Tuesday, August 22, 2023

What is heat flux and what is its influence in numerical analyzes in CFD Ansys software

 Heat flux is a measure of the rate of heat transfer per unit area. It has the units of watts per square meter (W/m^2). There are three modes of heat transfer: conduction, convection, and radiation. Conduction is the transfer of heat within a solid or between solids in contact. Convection is the transfer of heat between a solid surface and a moving fluid. Radiation is the transfer of heat by electromagnetic waves, which can occur in a vacuum.

To perform a heat transfer analysis in Ansys, you need to use Ansys Mechanical, which is a finite element analysis software that can solve various types of problems, including thermal problems. You can use Ansys Mechanical to perform steady-state or transient heat transfer analyses, depending on whether the thermal loads are constant or vary over time. You can also apply different types of boundary conditions, such as temperature, heat flux, heat generation, convection, and radiation.

To learn more about heat transfer and how to use Ansys Mechanical for thermal analysis, you can check out the following resources:

  • Introduction to Heat Transfer: This is a PDF document that explains the basic concepts and equations of heat transfer, including Fourier’s law, convection coefficient, and Stefan-Boltzmann law.
  • How to Perform a Heat Transfer Analysis — Lesson 1: This is a video tutorial that shows you how to set up and run a steady-state thermal analysis in Ansys Mechanical using a simple example.
  • Ansys Mechanical Heat Transfer: This is a training course that covers the topics and features of Ansys Mechanical related to heat transfer analysis, such as thermal contact, thermal stress, thermal fatigue, and coupled-field analysis.

The influence of heat flux in numerical analyses in CFD Ansys programs depends on the type and mode of heat transfer that is being modeled. Heat flux is a measure of the rate of heat transfer per unit area, and it can affect the temperature distribution, fluid flow, and thermal stress in a system.

There are three modes of heat transfer: conduction, convection, and radiation. Conduction is the transfer of heat within a solid or between solids in contact. Convection is the transfer of heat between a solid surface and a moving fluid. Radiation is the transfer of heat by electromagnetic waves, which can occur in a vacuum.

In Ansys Fluent, you can model different types of heat transfer problems using various methods and boundary conditions. For example, you can use the following methods to model heat flux:

  • Surface heat flux: You can specify a constant or variable heat flux on a surface as a boundary condition. This can be used to model external heat sources or sinks, such as heaters, coolers, or solar radiation.
  • Heat generation: You can specify a volumetric heat source or sink within a solid or fluid domain as a source term. This can be used to model internal heat sources or sinks, such as chemical reactions, electrical currents, or nuclear fission.
  • Convection: You can specify a convective heat transfer coefficient and a reference temperature on a surface as a boundary condition. This can be used to model heat transfer between a solid surface and a fluid with known properties, such as air or water.
  • Radiation: You can use various radiation models to account for the effects of thermal radiation on the system. This can be used to model heat transfer between surfaces or between surfaces and the environment by electromagnetic waves.

The influence of heat flux on the numerical results depends on the magnitude, direction, and distribution of the heat flux, as well as the material properties, geometry, and boundary conditions of the system. For example, a higher heat flux can result in higher temperatures, faster fluid velocities, and larger thermal stresses in the system. A directional heat flux can create temperature gradients and induce natural convection in the system. A non-uniform heat flux can cause local hot spots or cold spots in the system.

To perform a reliable and accurate CFD analysis of heat transfer problems in Ansys Fluent, you need to choose an appropriate mesh size, time step, solver settings, convergence criteria, and validation methods. You also need to verify and validate your results with experimental data or analytical solutions.

If you want to learn more about how to use Ansys Fluent for CFD analysis of heat transfer problems, you can check out the following resources:

  • Ansys Fluent Theory Guide: This is a PDF document that explains the theoretical background and mathematical formulations of various models and methods used in Ansys Fluent.
  • Ansys Fluent User’s Guide: This is a PDF document that provides detailed instructions on how to use Ansys Fluent for various types of problems and applications.
  • Ansys Fluent Tutorials: These are video tutorials that demonstrate how to set up and solve different types of CFD problems using Ansys Fluent.

I hope this information was helpful for you. If you have any other questions or requests, please let me know. 😊

What are SMART and GPAD functionality in Ansys Mechanical and examples to use

Fatique analysis in Ansys Mechanical (with models description)

How to improve (reduce) skewness factor in Ansys Mechanical and CFD

Monday, August 21, 2023

What are SMART and GPAD functionality in Ansys Mechanical and examples to use

 I'm glad you are interested in using the SMART function in Ansys Mechanical. The SMART function is a feature that allows you to simulate the crack growth in engineering structures under fatigue or static loading conditions. SMART stands for **S**tress-intensity factor based **M**esh **A**daptive **R**e-meshing **T**echnique¹. 

Some examples of using the SMART function in Ansys Mechanical are:

- [A video tutorial](^1^) that demonstrates how to use the SMART function to simulate Mode I dominant fatigue or static crack growth in a pump housing. The video shows how to set up the initial crack geometry and mesh, the boundary conditions and loads, and the crack growth parameters and criteria. The video also shows how to view the results of the crack growth simulation, such as the stress intensity factors, the crack front shape, and the crack opening displacement.

- [A white paper](^2^) that explains the benefits and features of the SMART function, such as the Unstructured Mesh Method (UMM) that reduces the preprocessing time by using an automatically generated all-tetrahedral mesh for crack fronts. The white paper also provides some case studies of using the SMART function for different applications, such as a surface crack in a pressure vessel, a through-thickness crack in a pipe elbow, and a corner crack in a plate.

- [A lecture note](^3^) that introduces the basics of using Ansys Workbench and Ansys Mechanical for structural and thermal analyses. The lecture note covers topics such as the user interface, the geometry import and creation, the meshing process, the material properties, the boundary conditions and loads, the solution settings and controls, and the post-processing tools. The lecture note also includes some exercises and examples of using Ansys Mechanical for different types of analyses, such as static structural, modal, harmonic response, transient dynamic, thermal, and thermal-stress.

Source: 

(1) ANSYS Mechanical: Fatigue Crack Growth Analysis using SMART ... - YouTube. https://www.youtube.com/watch?v=8fy0hmTITEQ.

(2) ANSYS Mechanical: Fatigue Crack Growth Analysis using SMART ... - YouTube. https://www.youtube.com/watch?v=8fy0hmTITEQ.

(3) Ansys SMART Crack Growth & Fracture Modeling White Paper | Ansys. https://www.ansys.com/resource-center/white-paper/smart-fracture.

(4) Lecture 1 Introduction to ANSYS Workbench - Rice University. https://www.clear.rice.edu/mech517/WB16/lectures_trainee/Mechanical_Intro_16.0_L01_Intro.pdf.

Examples to use SMART function 

- [A video tutorial](^1^) that demonstrates how to use the SMART function to simulate Mode I dominant fatigue or static crack growth in a pump housing. The video shows how to set up the initial crack geometry and mesh, the boundary conditions and loads, and the crack growth parameters and criteria. The video also shows how to view the results of the crack growth simulation, such as the stress intensity factors, the crack front shape, and the crack opening displacement.

- [A white paper](^2^) that explains the benefits and features of the SMART function, such as the Unstructured Mesh Method (UMM) that reduces the preprocessing time by using an automatically generated all-tetrahedral mesh for crack fronts. The white paper also provides some case studies of using the SMART function for different applications, such as a surface crack in a pressure vessel, a through-thickness crack in a pipe elbow, and a corner crack in a plate.

- [A lecture note](^3^) that introduces the basics of using Ansys Workbench and Ansys Mechanical for structural and thermal analyses. The lecture note covers topics such as the user interface, the geometry import and creation, the meshing process, the material properties, the boundary conditions and loads, the solution settings and controls, and the post-processing tools. The lecture note also includes some exercises and examples of using Ansys Mechanical for different types of analyses, such as static structural, modal, harmonic response, transient dynamic, thermal, and thermal-stress.

I hope these examples help you to learn more about using the SMART function in Ansys Mechanical. If you have any questions or feedback, please let me know. 😊

Source:

(1) ANSYS Mechanical: Fatigue Crack Growth Analysis using SMART ... - YouTube. https://www.youtube.com/watch?v=8fy0hmTITEQ.

(2) ANSYS Mechanical: Fatigue Crack Growth Analysis using SMART ... - YouTube. https://www.youtube.com/watch?v=8fy0hmTITEQ.

(3) Ansys SMART Crack Growth & Fracture Modeling White Paper | Ansys. https://www.ansys.com/resource-center/white-paper/smart-fracture.

(4) Lecture 1 Introduction to ANSYS Workbench - Rice University. https://www.clear.rice.edu/mech517/WB16/lectures_trainee/Mechanical_Intro_16.0_L01_Intro.pdf.

GPAD function 

The GPAD function is a feature in Ansys Mechanical that allows you to perform adaptive meshing based on the geometry of the model. GPAD stands for **G**eometry-**P**reserving **A**daptive **D**iscretization³. The GPAD function enables you to start a simulation with a coarser mesh, and, as the model is solved, the solver monitors quantities like variation of stress in regions and automatically refines the mesh³. The mesh refinement is based on the underlying CAD geometry, not the initial coarse mesh. This means that the mesh refinement works closer to the true shape of the model².

The GPAD function can improve the accuracy and efficiency of structural mechanics simulations, especially in cases where the detailed geometry of the system plays a critical role in determining its physical behavior². For example, the GPAD function can be useful for simulating crack growth, extrusion, hyper-elasticity, and other nonlinear phenomena¹.

To use the GPAD function in Ansys Mechanical, you need to activate the Nonlinear Adaptive Region option in the Solution branch of the Outline tree. You can also specify the parameters for the adaptive meshing, such as the maximum number of remeshing cycles, the remeshing criterion, and the remeshing method¹.

You can find more information and examples about using the GPAD function in Ansys Mechanical in these videos¹⁴ and this white paper². I hope this answers your question. 😊


Source:

(1) Top 5 Features in Ansys Mechanical 2023 R1. https://www.ansys.com/blog/mechanical-2023-r1.

(2) Adaptive Meshing Preserves Geometry in Ansys Mechanical Release. https://simutechgroup.com/adaptive-meshing-preserves-geometry-in-ansys-mechanical-release/.

(3) How to Use Non-Linear Adaptive Meshing in Ansys Mechanical. https://www.youtube.com/watch?v=T90iGxHkmvQ.

(4)  https://go.edrmedeso.com/edrmedeso-tr.

(5)  https://www.linkedin.com/company/edr&.

(6) https://www.facebook.com/edrmedeso.

(7)https://twitter.com/EDRMedeso.

(8)  https://digitallabs.edrmedeso.com/new.

Some examples of using the GPAD function in Ansys Mechanical are:

- [A blog post](^1^) that lists the top 5 features in Ansys Mechanical 2023 R1, including the GPAD function. The blog post explains the benefits and features of the GPAD function, such as improved accuracy and efficiency, reduced preprocessing time, and automatic remeshing. The blog post also shows a screenshot of how to activate the GPAD function in the Solution branch of the Outline tree.

- [A video tutorial] that demonstrates how to use the GPAD function to simulate a crack growth problem in a pressure vessel. The video shows how to set up the initial crack geometry and mesh, the boundary conditions and loads, and the crack growth parameters and criteria. The video also shows how to view the results of the crack growth simulation, such as the stress intensity factors, the crack front shape, and the crack opening displacement.

- [A white paper](^2^) that explains the technical details of the GPAD function, such as the Unstructured Mesh Method (UMM) that reduces the preprocessing time by using an automatically generated all-tetrahedral mesh for crack fronts. The white paper also provides some case studies of using the GPAD function for different applications, such as a surface crack in a pressure vessel, a through-thickness crack in a pipe elbow, and a corner crack in a plate.

I hope these examples help you to learn more about using the GPAD function in Ansys Mechanical. If you have any questions or feedback, please let me know. 😊

Source: 

(3) Top 5 Features in Ansys Mechanical 2023 R1. https://www.ansys.com/blog/mechanical-2023-r1.

(4) Adaptive Meshing Preserves Geometry in Ansys Mechanical Release .... https://simutechgroup.com/adaptive-meshing-preserves-geometry-in-ansys-mechanical-release/.

Fatique analysis in Ansys Mechanical (with models description)

How to improve (reduce) skewness factor in Ansys Mechanical and CFD

What is Ansys Speos and how to use

Fatique analysis in Ansys Mechanical (with models description)

 ANSYS Mechanical is a software that can help you perform fatigue analysis on your models and predict the fatigue life and damage of your materials. ANSYS Mechanical offers various tools and features to help you set up, run, and post-process your fatigue analysis. For example:

I searched the web  and found some results that might be helpful. The first result is a course overview of ANSYS Mechanical Fatigue that covers the use of the Fatigue tool to perform stress-based and strain-based fatigue analysis in both the time and frequency domains. The second result is a video tutorial that explains how to perform fatigue analysis in ANSYS Workbench. The third result is another video tutorial that shows how to use the Fatigue tool in ANSYS Mechanical. The fourth result is a PDF document that provides an introduction to ANSYS fatigue analysis.

Below You can see the models of SN curve, EN curve and Morrow models. These are some of the models that are used to predict the fatigue life of a material based on the stress or strain cycles.

  • SN curve: This is a stress-life (S-N) curve that plots the stress amplitude versus the number of cycles to failure for a material. The SN curve is usually obtained from experimental tests under constant amplitude loading and fully reversed loading (R=-1), where R is the ratio of minimum to maximum stress. The SN curve can have different slopes depending on the stress level and the material behavior. For example, some materials may exhibit a fatigue limit, which is a stress level below which the material can endure an infinite number of cycles without failure. Other materials may not have a fatigue limit and show a continuous decrease in fatigue life with increasing stress. The SN curve can be used to estimate the fatigue life of a material when the stress is mostly elastic and the mean stress is low.
  • EN curve: This is a strain-life (E-N) curve that plots the strain amplitude versus the number of cycles to failure for a material. The EN curve is also obtained from experimental tests under constant amplitude loading and fully reversed loading (R=-1), but it considers both the elastic and plastic components of strain. The EN curve can be divided into three regions: low-cycle fatigue (LCF), high-cycle fatigue (HCF), and transition fatigue. In the LCF region, the plastic strain dominates and the material fails after a relatively small number of cycles. In the HCF region, the elastic strain dominates and the material fails after a relatively large number of cycles. In the transition region, both elastic and plastic strains are significant and the material exhibits an intermediate fatigue life. The EN curve can be used to estimate the fatigue life of a material when the strain is partly plastic and the mean stress is high.
  • Morrow model: This is a mean stress correction model that modifies the EN curve to account for the effect of mean stress on fatigue life. The mean stress is the average of the maximum and minimum stress in a cycle. The mean stress can influence the fatigue life of a material by changing the effective strain amplitude and causing either damage accumulation or damage recovery. The Morrow model assumes that only the plastic strain amplitude is affected by the mean stress, while the elastic strain amplitude remains constant. The Morrow model uses a modified endurance limit to calculate the corrected plastic strain amplitude based on the mean stress. The Morrow model can be used to improve the accuracy of fatigue life prediction when the mean stress is not zero.

I hope this description helps you understand more about these models. 😊

How to improve (reduce) skewness factor in Ansys Mechanical and CFD

What is Ansys Speos and how to use

What is Young Modulus in Ansys Mechanical (impact of this factor for structural analysis)

How to define porosity (porous medium) in Ansys CFD (Fluent, CFX)

How to improve (reduce) skewness factor in Ansys Mechanical and CFD

 Skewness is a measure of how much a cell deviates from an ideal shape. It is one of the most important indicators of mesh quality, as highly skewed cells can reduce the accuracy and stability of the numerical solution. Skewness is defined differently for different types of cells, such as triangles, tetrahedra, hexahedra, or polyhedra. In general, skewness is calculated as the difference between the shape of the cell and the shape of an equilateral cell of equivalent volume. The skewness value ranges from 0 to 1, where 0 means no skewness and 1 means maximum skewness. A good mesh should have low skewness values for most of the cells.

In ANSYS Mechanical and CFD, you can check the skewness of your mesh using various methods. For example, you can use the Report Quality button in the General task page to print a message to the console that shows the maximum cell skewness in your mesh. You can also use the Equivolume Skewness option in the Mesh Metric dropdown list in the Mesh Control task page to display a contour plot of the skewness on your mesh3. You can also use the Mesh Quality Criteria dialog box to set the minimum acceptable skewness value for your mesh and generate a report that shows how many cells violate this criterion.

There are different ways to improve your mesh quality and reduce the skewness in ANSYS. Here are some suggestions that you can try:

  • Modify your geometry to avoid sharp angles, small gaps, or thin features that can cause highly skewed cells. You can use the Geometry tool in ANSYS to edit your model and simplify it if possible.
  • Choose an appropriate element type for your mesh, such as tetrahedra, hexahedra, or polyhedra. Different element types have different skewness definitions and criteria. Generally, hexahedral elements have lower skewness than tetrahedral elements, but they are more difficult to generate for complex geometries. Polyhedral elements can adapt to any geometry and have lower skewness than tetrahedral elements, but they require more memory and computational time.
  • Adjust your element size to balance between accuracy and efficiency. A smaller element size can capture more details of the geometry and the physics, but it can also increase the number of cells and the skewness. A larger element size can reduce the number of cells and the skewness, but it can also lose some important information and introduce errors. You can use the Size Function option in ANSYS Meshing to control the element size based on various criteria, such as curvature, proximity, or sphere of influence.
  • Apply different meshing methods to different parts of your geometry, such as patch conforming, patch independent, or cutcell. Different meshing methods have different advantages and disadvantages in terms of quality, speed, and robustness. You can use the Method option in ANSYS Meshing to select the best meshing method for each part of your model.
  • Refine your mesh based on the change in cell volume or the gradient of cell volume. This can improve the smoothness of your mesh and reduce the skewness. You can use the Refinement option in ANSYS Meshing to refine your mesh based on various criteria, such as face size, face proximity, or face curvature.

You can check the skewness of your mesh using various methods in ANSYS Mechanical and CFD. For example:

There are other ways to improve the skewness factor besides the ones I mentioned in my previous response. Here are some additional suggestions that you can try:

I hope these suggestions help you further improve your skewness factor in ANSYS. 😊

If U want to read more interesting tips and tutorials try links below 

Cooling process of the gear on Transient Thermal (Ansys Workbench)

What is Ansys Speos and how to use

What is Young Modulus in Ansys Mechanical (impact of this factor for structural analysis)

How to define porosity (porous medium) in Ansys CFD (Fluent, CFX)

Sunday, August 20, 2023

Cooling process of the gear on Transient Thermal (Ansys Workbench)

 Transient Thermal module is a type of analysis that allows you to simulate the temperature changes and heat transfer in a system over time. It is useful for studying problems that involve time-dependent thermal loads, such as heat treatment, electronic cooling, engine heating, etc.

In Transient Thermal module, you need to specify the initial temperature distribution, the material properties (such as density, specific heat, and thermal conductivity), the boundary conditions (such as convection, radiation, and heat flux), and the time steps for the analysis. The module will solve the heat conduction equation for each time step and generate the results for the temperature, heat flux, heat transfer coefficient, etc.

You can also use Transient Thermal module to perform coupled thermal-structural analysis, where the thermal results are transferred to a structural analysis to calculate the thermal stresses and strains. This can help you evaluate the effects of thermal expansion, contraction, and deformation on your system.

If you want to learn more about Transient Thermal module in Ansys workbench, you can check out some of these resources:

- [Intro to Transient Thermal Analysis - ANSYS Innovation Courses](^5^): This is a PDF document that introduces the basics of transient thermal analysis and the governing equation.

- [Transient Thermal Analysis in ANSYS](^1^): This is a YouTube video that shows you how to do a transient thermal analysis in Ansys workbench with an example problem.

- [Transient heat transfer analysis using ANSYS workbench](^2^): This is another YouTube video that demonstrates how to perform transient heat transfer analysis using Ansys workbench with a different example problem.

I hope this helps you understand what is Transient Thermal module in Ansys workbench.

Source:

(1) Intro to Transient Thermal Analysis - ANSYS Innovation Courses. https://courses.ansys.com/wp-content/uploads/2020/05/Lesson-1-Introduction-to-transient-analysis.pdf.

(2) Transient Thermal Analysis in ANSYS - YouTube. https://www.youtube.com/watch?v=4Jj0s-DAvfg.

(3) Transient heat transfer analysis using ANSYS workbench. https://www.youtube.com/watch?v=wJW6IIovyPo.

(4) ANSYS Transient Thermal Tutorial - Convection of a Bar in Air. https://www.youtube.com/watch?v=fd0xQQ1IGvw.

(5) Setup Transient Thermal Analysis - ANSYS Innovation Courses. https://courses.ansys.com/index.php/courses/radiation-between-surfaces/lessons/physics-setup-lesson-5-16/topic/setup-transient-thermal-analysis/.

Friday, August 18, 2023

What is Ansys Speos and how to use

 ANSYS Speos is a software that can simulate and optimize the optical performance of systems, such as lighting, cameras, sensors, displays, etc. It can help you design and validate optical systems that meet your specifications and requirements. You can use ANSYS Speos when you want to:

  • Predict the illumination and optical behavior of your system in realistic conditions
  • Evaluate the impact of optical elements on human vision and perception
  • Optimize the optical design to improve efficiency, quality, and safety
  • Integrate optical simulation with other ANSYS products for multiphysics analysis
  • Reduce prototyping time and costs by using virtual testing and validation

Some of the features and capabilities of ANSYS Speos are:

I hope this gives you more information about ANSYS Speos and its features. If you want to learn more about how to use ANSYS Speos effectively, you can check out these sources: Ansys, Ansys Training, CADFEM.

To model in ANSYS Speos, you need to follow some general steps, such as:

  • Define the geometry of your optical system using ANSYS SpaceClaim or import it from another CAD software.
  • Define the optical properties of your materials, sources, and sensors using the Speos Optical Properties panel.
  • Define the simulation settings, such as the type of analysis, the wavelength range, the ray tracing options, etc., using the Speos Simulation panel.
  • Run the simulation and view the results using the Speos Results panel or the Speos Live Preview feature.
  • Post-process and analyze the results using various tools, such as sensors, probes, cameras, etc., or export them to other ANSYS products for multiphysics analysis.

These steps may vary depending on the specific application and complexity of your optical system. You can find more detailed instructions and examples on how to model in ANSYS Speos from these sources: Ansys Training, Ansys, Ansys Optics.

What is Young Modulus in Ansys Mechanical (impact of this factor for structural analysis)

 

Young’s modulus is a mechanical property that measures the stiffness of a solid material. It defines the relationship between stress (force per unit area) and strain (proportional deformation) in a material in the linear elasticity regime of a uniaxial deformation. Mathematically, this can be expressed as:


Young’s modulus is one of the input parameters when performing structural analysis in ANSYS Workbench. It affects the deformation and stress distribution of the material under external loads. A higher Young’s modulus means a stiffer material that resists deformation more. A lower Young’s modulus means a more flexible material that deforms more easily.

To perform structural analysis in ANSYS Workbench, you need to define the geometry, the material properties, the mesh, the boundary conditions, and the loads of your problem. Then, you need to solve the problem and post-process the results. You can use ANSYS Mechanical or ANSYS APDL to perform structural analysis12.

For more information on Young’s modulus and its impact on ANSYS Workbench, you can check out these sources: Ansys Learning Forum, Omnexus, Wikipedia.

The impact of Young’s modulus on the results in ANSYS Mechanical depends on the type of analysis and the material behavior. Young’s modulus is a measure of the stiffness of a material, which affects how much it deforms and stresses under external loads. Generally, a higher Young’s modulus means a lower deformation and a higher stress, while a lower Young’s modulus means a higher deformation and a lower stress.

For example, if you are performing a linear static analysis, which assumes that the material is elastic and the deformation is small, the Young’s modulus directly affects the displacement and stress results. The displacement is inversely proportional to the Young’s modulus, while the stress is directly proportional to the Young’s modulus. This means that if you increase the Young’s modulus of a material, you will get smaller displacements and larger stresses, and vice versa1.

However, if you are performing a nonlinear analysis, which accounts for large deformations, plasticity, or other nonlinear effects, the Young’s modulus is not the only factor that affects the results. You also need to consider other material properties, such as the yield strength, the hardening model, the Poisson’s ratio, etc. The Young’s modulus still affects the initial stiffness and elastic response of the material, but it may not be the dominant factor in determining the final deformation and stress results2.

Therefore, to understand the impact of Young’s modulus on the results in ANSYS Mechanical, you need to know the type of analysis you are performing, the material model you are using, and the boundary conditions and loads you are applying. You can also perform a parametric study or a sensitivity analysis to see how changing the Young’s modulus affects the results3. For more information on how to perform structural analysis in ANSYS Mechanical, you can check out these sources: Ansys Learning Forum, Ansys Blog, YouTube.

Interesting facts about Young Modulus 

Young’s modulus is a numerical constant that describes the elastic properties of a solid material when it is stretched or compressed in one direction. It is named after the 18th-century British scientist Thomas Young, who first proposed the concept of elasticity in 18071. However, the concept was developed earlier by Leonhard Euler in 1727, and the first experiments that used Young’s modulus in its current form were performed by Giordano Riccati in 1782.

Young’s modulus is a measure of the stiffness of a material, or how much it resists deformation under an applied force. A material with a high Young’s modulus is more rigid and less elastic than a material with a low Young’s modulus. For instance, steel has a Young’s modulus of about 200 GPa, which is about three times higher than that of aluminum. This means that steel is much harder to stretch or compress than aluminum.

Young’s modulus is only valid for small deformations that are reversible, meaning that the material returns to its original shape when the force is removed. This is called the elastic region of the material. If the force is increased beyond a certain point, the material will undergo permanent deformation, or plasticity. This is called the plastic region of the material. The point at which the material transitions from elastic to plastic behavior is called the yield point or yield strength of the material.

Young’s modulus is an important parameter in engineering and design, as it helps to determine how much a material can withstand stress without breaking or deforming. It also affects other properties of materials, such as thermal expansion, vibration, sound propagation, and elasticity of springs.

I hope this information was helpful and interesting for you. If you have any other questions or requests, please let me know. 😊

How to define porosity (porous medium) in Ansys CFD (Fluent, CFX)

 To model porosity in ANSYS Fluent, you need to define the porous zone and the porous media properties in the setup. You can follow these steps:

  • In the Fluent interface, go to the Cell Zone Conditions panel and select the zone that you want to make porous. Check the Porous Zone option and click Edit.
  • In the Porous Zone panel, you can choose between two methods to specify the porous media resistance: the Superficial Velocity method or the Physical Velocity method. The Superficial Velocity method uses the superficial velocity (the velocity of the fluid if there were no porosity) to calculate the pressure drop across the porous zone. The Physical Velocity method uses the physical velocity (the velocity of the fluid inside the pores) to calculate the pressure drop across the porous zone. You can also choose between isotropic or anisotropic porosity, depending on whether the porosity is uniform or varies in different directions.
  • Depending on the method and the type of porosity you choose, you need to enter different parameters for the porous media. For example, if you choose the Superficial Velocity method and isotropic porosity, you need to enter the following parameters:
  • Click OK to apply your settings and close the panel.

You can also use user-defined functions (UDFs) to specify more complex or variable porous media properties. For more information on how to model porosity in ANSYS Fluent, you can check out these sources: YouTube, YouTube, YouTube, Ansys Learning Forum.

To model porosity in ANSYS CFX, you need to define the porous zone and the porous media properties in the setup. You can follow these steps:

  • In the CFX interface, go to the Cell Zone Conditions panel and select the zone that you want to make porous. Check the Porous Zone option and click Edit.
  • In the Porous Zone panel, you can choose between two methods to specify the porous media resistance: the Superficial Velocity method or the Physical Velocity method. The Superficial Velocity method uses the superficial velocity (the velocity of the fluid if there were no porosity) to calculate the pressure drop across the porous zone. The Physical Velocity method uses the physical velocity (the velocity of the fluid inside the pores) to calculate the pressure drop across the porous zone. You can also choose between isotropic or anisotropic porosity, depending on whether the porosity is uniform or varies in different directions.
  • Depending on the method and the type of porosity you choose, you need to enter different parameters for the porous media. For example, if you choose the Superficial Velocity method and isotropic porosity, you need to enter the following parameters:
  • Click OK to apply your settings and close the panel.

You can also use user-defined functions (UDFs) to specify more complex or variable porous media properties. For more information on how to model porosity in ANSYS CFX, you can check out these sources: YouTube, YouTube, YouTube, CFD Online.

If U want learn some other interested topics about Ansys, check links below:

How to define Joint in Ansys Static Structural and examples to use

Types of contacts on Ansys Static Structural and examples to use

How to model cracking phenomena in Ansys Mechanical (Structural)

How to define symmetry in Ansys Mechanical and CFD (CFX, Fluent)

Thursday, August 17, 2023

How to model cracking phenomena in Ansys Mechanical (Structural)

 Cracking phenomena are the processes of initiation, propagation, and failure of cracks in materials or structures due to various factors, such as stress, temperature, fatigue, corrosion, etc. Cracking phenomena can affect the performance, safety, and reliability of engineering systems and components. Therefore, it is important to be able to model and analyze cracking phenomena using simulation tools such as Ansys Mechanical.

Ansys Mechanical is a software product that provides finite element analysis (FEA) solutions for modeling structural mechanics problems. Ansys Mechanical can handle linear and nonlinear, static and dynamic, and thermal and coupled physics problems. Ansys Mechanical can also simulate various types of materials, such as metals, plastics, composites, and biomaterials.

To model cracking phenomena in Ansys Mechanical, you need to use some special features and capabilities that are available in the software. Some of these features are:

  • Fracture: This is a feature that allows you to define and apply fracture criteria to your model based on stress intensity factors (SIFs), energy release rates (ERRs), or J-integrals. Fracture can be used to simulate linear elastic fracture mechanics (LEFM) or nonlinear fracture mechanics (NLFM) problems. Fracture can also be used to model different types of cracks, such as pre-meshed cracks, arbitrary cracks, or semi-elliptical cracks.
  • SMART Crack Growth: This is a feature that allows you to simulate the growth and propagation of cracks in your model using separating morphing adaptive remeshing technology (SMART). SMART Crack Growth can handle 2D or 3D crack problems with complex geometries and loading conditions. SMART Crack Growth can also account for mixed-mode loading, contact effects, plasticity effects, and thermal effects.
  • XFEM: This is a feature that allows you to model cracks without explicitly meshing them using the extended finite element method (XFEM). XFEM can enrich the standard finite element approximation with additional functions that capture the discontinuity and singularity of the crack. XFEM can be used to model stationary or propagating cracks with various criteria, such as maximum hoop stress, maximum circumferential stress, or Paris law.

These are some of the features that you can use to model cracking phenomena in Ansys Mechanical. You can also use other features and tools that are integrated with Ansys Mechanical, such as Ansys Workbench, Ansys Fluent, Ansys APDL, etc., to create and manage your simulation projects.

If you want to learn more about how to use these features and tools to model cracking phenomena in Ansys Mechanical, you can check out some of the sources that I found using Bing:

  • Ansys Multiphysics Simulation for Crack Propagation Analysis: This is a webinar that demonstrates a multiphysics simulation for crack propagation analysis using Ansys Workbench, Ansys Mechanical, and Ansys Fluent. You will learn how to use SMART Crack Growth to analyze crack growth due to thermo-mechanical fatigue (TMF).
  • Get Cracking with ANSYS Workbench 19.2: This is an article that revisits Ansys Workbench to carry out a series of fracture mechanics analyses using SMART Crack Growth. You will learn how to create and edit joints in Ansys Workbench, how to specify the degrees of freedom, stiffness, damping, and friction properties for the joints, how to apply loads and moments to the joints, and how to post-process the results of the joint analysis.
  • how to create a crack on a 3D surface body in ANSYS workbench?: This is a forum thread that discusses how to create a crack on a 3D surface body in Ansys Workbench using Pre-Meshed Crack option. You will learn how to select the crack edge, top surface, bottom surface, and coordinate system for the crack definition.
If you are looking for some material models that can handle the cracking phenomena in Ansys Mechanical, you are in luck! I have found some amazing models that can do just that. Let me tell you more about them:

- **Anisotropic Plasticity using Hill Potential**: This model is perfect for metals that have different strengths in different directions, like a sheet of paper. It can show you how the metal gets damaged and breaks due to bending or stretching.
- **Cast Iron**: This model is great for cast iron materials, which are very strong when you squeeze them, but very weak when you pull them apart. It can show you how the cast iron cracks and shatters under tension, and how it depends on the temperature, the speed of loading, and the shape of the grains.
- **Microplane**: This model is awesome for concrete, which is a mixture of rocks, cement, and water. It can show you how the concrete cracks and softens when you pull it, and how it crushes and expands when you push it.
- **Shape Memory Alloys**: This model is amazing for shape memory alloys, which are metals that can change their shape when you heat them or stress them. It can show you how the shape memory alloys transform from one phase to another, and how they recover their original shape after being deformed.

These are some of the material models that can help you with your cracking phenomena in Ansys Mechanical. You can learn more about them by clicking on the links I have provided. I hope you find this interesting and helpful. 

The sources for the text are:

- [Understand a Design’s Breaking Point with Simple Crack Propagation Simulations](^1^): This is a blog post from Ansys that explains how to use the unstructured mesh method (UMM) and the separating morphing and adaptive remeshing technology (SMART) to simulate crack propagation in Ansys Mechanical. It also compares the results of UMM with the traditional hexahedral mesh method.
- [Material property data for engineering materials](^2^): This is a PDF document from Ansys that provides some material property data for common engineering materials, such as density, thermal conductivity, elastic modulus, etc. It also includes some physical constants, such as the gas constant, the Boltzmann constant, etc.
- [Simulate Brittle Cracking](^3^): This is a forum post from Ansys Learning Forum that discusses how to simulate the cracking of a nutshell in Ansys static structural. It also provides some screenshots of the model and the boundary conditions.

(1) Understand a Design’s Breaking Point with Simple Crack ... - Ansys. https://www.ansys.com/blog/breaking-point-crack-propagation-strength-of-materials.
(2) Material property data for engineering materials - Ansys. https://www.ansys.com/content/dam/amp/2021/august/webpage-requests/education-resources-dam-upload-batch-2/material-property-data-for-eng-materials-BOKENGEN21.pdf.
(3) Simulate Brittle Cracking - Ansys Learning Forum. https://forum.ansys.com/forums/topic/simulate-brittle-cracking/.

I hope this helps you understand how to model cracking phenomena in Ansys Mechanical. If you have any questions or feedback, please let me know. 😊



How to define symmetry in Ansys Mechanical and CFD (CFX, Fluent)

 Symmetry is a property of a system or a phenomenon that remains unchanged under certain transformations, such as reflection, rotation, or translation. Symmetry can be used to simplify the modeling and analysis of complex structures or problems by reducing the size and complexity of the model. Symmetry can also improve the accuracy and efficiency of the solution by eliminating unnecessary degrees of freedom and reducing numerical errors.


Ansys Mechanical is a software product that provides finite element analysis (FEA) solutions for modeling structural mechanics problems. Ansys Mechanical can handle linear and nonlinear, static and dynamic, and thermal and coupled physics problems. Ansys Mechanical can also simulate various types of materials, such as metals, plastics, composites, and biomaterials.

To model symmetry in Ansys Mechanical, you need to use some special features and capabilities that are available in the software. Some of these features are:

  • Symmetry Region: This is a feature that allows you to define and apply symmetry boundary conditions to your model based on the type and plane of symmetry. Symmetry Region can be used to model planar symmetry, cylindrical symmetry, spherical symmetry, or sector symmetry. Symmetry Region can also visually expand the results to show the full model for symmetric cases.
  • Slice: This is a feature that allows you to cut or split your model into smaller parts or slices based on a plane or a surface. Slice can be used to create symmetric parts or sectors from an original model. Slice can also preserve the material properties and mesh quality of the original model.
  • Coordinate System: This is a feature that allows you to create and align local coordinate systems based on the geometry or orientation of your model. Coordinate System can be used to define the direction and location of loads, supports, joints, or other features in your model. Coordinate System can also be used to specify the plane or axis of symmetry for your model.

Here are some examples of how to use these features to model symmetry in Ansys Mechanical for different types of problems:

  • Understanding When to Take Advantage of Symmetry Using Ansys Mechanical — Lesson 3: This is a video that shows how to use Symmetry Region to model planar symmetry and sector symmetry for a mechanical part with bolted connections. You will learn how to split bodies for symmetry in Ansys SpaceClaim, how to connect line bodies with solid bodies via Contact Region in Ansys Mechanical, how to create and align local Coordinate Systems based on geometry, how to define Bolt Pretension load in Ansys Mechanical, and how to visually expand symmetry results to show the full model.
  • How to setup Cyclic Symmetry model in ANSYS Workbench Mechanical: This is a video that shows how to use Slice and Coordinate System to model cylindrical symmetry for a turbine blade with centrifugal loading. You will learn how to slice a 3D body into a single-sector body in Ansys SpaceClaim, how to create a cylindrical coordinate system in Ansys Mechanical, how to apply rotational velocity and pressure loads in Ansys Mechanical, and how to post-process the results using cyclic expansion.
  • Understanding when to Take Advantage of Symmetry - Lesson 3: This is an article that revisits Ansys Workbench to carry out a series of fracture mechanics analyses using SMART Crack Growth. You will learn how to use Slice and Symmetry Region to model planar symmetry for a cracked plate with tensile loading. You will also learn how to apply fracture criteria based on stress intensity factors (SIFs) or energy release rates (ERRs) in Ansys Mechanical.

CFD Software 

Ansys Fluent and Ansys CFX are software products that provide computational fluid dynamics (CFD) solutions for modeling fluid flow and heat transfer phenomena. Ansys Fluent and Ansys CFX can handle various types of fluid flow problems, such as laminar or turbulent, compressible or incompressible, steady or transient, etc. Ansys Fluent and Ansys CFX can also simulate various types of fluids, such as gases, liquids, multiphase, reacting, etc.

To model symmetry in Ansys Fluent and Ansys CFX, you need to use some special features and capabilities that are available in the software. Some of these features are:

  • Symmetry Boundary Condition: This is a feature that allows you to define and apply symmetry boundary conditions to your model based on the type and plane of symmetry. Symmetry boundary condition can be used to model planar symmetry, cylindrical symmetry, spherical symmetry, or sector symmetry. Symmetry boundary condition can also visually expand the results to show the full model for symmetric cases.
  • Slice: This is a feature that allows you to cut or split your model into smaller parts or slices based on a plane or a surface. Slice can be used to create symmetric parts or sectors from an original model. Slice can also preserve the material properties and mesh quality of the original model.
  • Coordinate System: This is a feature that allows you to create and align local coordinate systems based on the geometry or orientation of your model. Coordinate System can be used to define the direction and location of loads, supports, boundaries, or other features in your model. Coordinate System can also be used to specify the plane or axis of symmetry for your model.

I see that you want to see some examples of how to use symmetry in Ansys CFX and Ansys Fluent. Symmetry is a property of a system or a phenomenon that remains unchanged under certain transformations, such as reflection, rotation, or translation. Symmetry can be used to simplify the modeling and analysis of complex fluid flow problems by reducing the size and complexity of the model. Symmetry can also improve the accuracy and efficiency of the solution by eliminating unnecessary degrees of freedom and reducing numerical errors.

Ansys CFX and Ansys Fluent are software products that provide computational fluid dynamics (CFD) solutions for modeling fluid flow and heat transfer phenomena. Ansys CFX and Ansys Fluent can handle various types of fluid flow problems, such as laminar or turbulent, compressible or incompressible, steady or transient, etc. Ansys CFX and Ansys Fluent can also simulate various types of fluids, such as gases, liquids, multiphase, reacting, etc.

To use symmetry in Ansys CFX and Ansys Fluent, you need to use some special features and capabilities that are available in the software. Some of these features are:

  • Symmetry Boundary Condition: This is a feature that allows you to define and apply symmetry boundary conditions to your model based on the type and plane of symmetry. Symmetry boundary condition can be used to model planar symmetry, cylindrical symmetry, spherical symmetry, or sector symmetry. Symmetry boundary condition can also visually expand the results to show the full model for symmetric cases.
  • Slice: This is a feature that allows you to cut or split your model into smaller parts or slices based on a plane or a surface. Slice can be used to create symmetric parts or sectors from an original model. Slice can also preserve the material properties and mesh quality of the original model.
  • Coordinate System: This is a feature that allows you to create and align local coordinate systems based on the geometry or orientation of your model. Coordinate System can be used to define the direction and location of loads, supports, boundaries, or other features in your model. Coordinate System can also be used to specify the plane or axis of symmetry for your model.

Here are some examples of how to use these features to model symmetry in Ansys CFX and Ansys Fluent for different types of problems:

  • Show Symmetry at CFD-POST (Results): This is a forum thread that shows how to use Symmetry Boundary Condition to model planar symmetry and sector symmetry for a half structure with an obstacle in the flow. You will learn how to set Symmetry (at Z axis) in Ansys Fluent, how to enable Beta Options in Workbench, and how to visually expand symmetry results in CFD-POST.
  • ANSYS Fluent Tutorial | Parametric Analysis In ANSYS Fluent | ANSYS Fluent Beginners Tutorial | CFD: This is a video that shows how to use Slice and Coordinate System to model planar symmetry for an airfoil with angle of attack variation. You will learn how to slice a 2D body into a half body in Ansys SpaceClaim, how to create a Cartesian coordinate system in Ansys Fluent, how to apply inlet velocity and outlet pressure boundary conditions in Ansys Fluent, and how to post-process the results using parametric analysis.

I hope these examples help you learn how to use symmetry in Ansys CFX, Fluent and Mechanical. If you have any questions or feedback, please let me know. 😊


How to define Joint in Ansys Static Structural and examples to use

  Joint boundary condition is a type of connection element that allows you to model the relative motion and interaction between two or more bodies in a structural analysis. Joint boundary condition can be used to simulate various types of joints, such as revolute, cylindrical, spherical, planar, slot, universal, and fixed joints. Joint boundary condition can also be used to apply loads and moments to the connected bodies.

To use joint boundary condition in Ansys Static Structural, you need to follow these steps:

  • In the Model tree, right-click Connections and select Insert > Joint.
  • In the Details view, select the type of joint you want to create from the drop-down list.
  • In the Geometry section, select the two or more bodies that you want to connect with the joint. You can also specify the location and orientation of the joint coordinate system (JCS) using the options available.
  • In the Definition section, specify the degrees of freedom (DOF) that you want to allow or restrict for the joint. You can also define stiffness, damping, and friction properties for the joint if needed.
  • In the Loads section, you can apply forces and moments to the joint in any direction. You can also define time-dependent or frequency-dependent loads using tables or functions.
  • Click Generate to create the joint boundary condition.

You can also modify or delete the joint boundary condition by right-clicking it in the Model tree and selecting Edit or Delete.

Here are some examples of how to use joint boundary condition in Ansys Static Structural for different types of joints:

  • Revolute Joint: This example shows how to model a revolute joint between a crank and a connecting rod of an engine. The revolute joint allows rotation about one axis and restricts all other DOF. A torque is applied to the crank and a force is applied to the connecting rod. The results show the stress distribution and displacement of the parts due to the joint motion.
  • Cylindrical Joint: This example shows how to model a cylindrical joint between a piston and a cylinder of an engine. The cylindrical joint allows translation and rotation along one axis and restricts all other DOF. A pressure load is applied to the piston and a fixed support is applied to the cylinder. The results show the stress distribution and displacement of the parts due to the joint motion.
  • Spherical Joint: This example shows how to model a spherical joint between a ball and a socket of a hip implant. The spherical joint allows rotation about three axes and restricts all other DOF. A force is applied to the ball and a fixed support is applied to the socket. The results show the stress distribution and displacement of the parts due to the joint motion.

I have searched the web for some relevant sources that show how to use joint boundary condition in Ansys Mechanical for different types of joints, such as revolute, cylindrical, spherical, planar, slot, universal, and fixed joints. You can watch some videos or read some articles that explain how to create and edit joints in Ansys Mechanical, how to specify the degrees of freedom, stiffness, damping, and friction properties for the joints, how to apply loads and moments to the joints, and how to post-process the results of the joint analysis. Here are some links that you can check out:

  • Working with Joints in ANSYS Mechanical | CAE Associates | ANSYS e-Learning: This video shows some of the tools and capabilities in Ansys Workbench v14.5 for defining and working with joints. It covers how to create joints using geometry scoping or remote points, how to modify or delete joints, how to use joint probes to plot joint forces and moments, and how to use joint loads to apply prescribed motion or displacement to joints.
  • ANSYS Explicit Dynamics: Using Joints, Joint Loads and Probes: This video shows how you can use joints in an Ansys Explicit Dynamics analysis to simulate the actual failure of an engine piston rod, which would not be possible with rigid bodies. It shows various joint types, joint loads, and joint probes that are available in Ansys Explicit Dynamics.
  • How to Model Joints via Constraints in Ansys Workbench Mechanical: This video shows how you can model joints via constraints in Ansys Workbench Mechanical using the command snippet feature. It explains how to use the MPC184 element type to create different types of joints, such as revolute, cylindrical, spherical, etc., and how to export the joint forces and moments using APDL commands.
  • Ansys Mechanical: All About Joints: This article covers some MAPDL commands to export joint element forces and moments as well as some strategies for working with joints in Ansys Mechanical. It explains why joints are useful for modeling complex mechanisms and interactions between bodies, and how to define and post-process joints using MAPDL.
  • Lecture 5 Modeling Connections: This lecture slides provide an overview of the different types of connections available in Ansys Mechanical, such as contact, bonded contact, bolted connection, spot welds, beam connection, etc. It also introduces the concept of joint boundary condition and shows some examples of using joints in Ansys Mechanical.

I hope these examples help you learn how to use joint boundary condition in Ansys Mechanical. If you have any questions or feedback, please let me know. 😊

If U want learn some other interested topics about Ansys, check links below:

Types of contacts on Ansys Static Structural and examples to use




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