To prepare a proper mesh for structural analysis in Ansys Workbench, you need to follow some steps and consider some factors. Here are some tips and resources that might help you:
- Before you start meshing, you need to upload your CAD model or geometry into Ansys Mechanical and decide what features need to be meshed and what features can be defeatured. Defeaturing means removing unnecessary details from your geometry to save time and simplify the meshing process. For example, you can use Ansys SpaceClaim to defeature a name plate on your geometry if it is not relevant for your analysis 1.
- You also need to choose the type of mesh you want to create: structured or unstructured. Structured meshes have regular shapes and patterns, while unstructured meshes have irregular shapes and sizes. Structured meshes are usually more efficient and accurate, but they are harder to generate for complex geometries. Unstructured meshes are more flexible and easy to generate, but they may require more elements and computational resources 1.
- To create a structured mesh in Ansys Meshing, you can use various methods such as sweep, multizone, hex-dominant, or mapped face meshing. These methods allow you to control the shape and size of the elements along the geometry. You can also use inflation layers to refine the mesh near the boundaries where gradients are high 2.
- To create an unstructured mesh in Ansys Meshing, you can use methods such as tetrahedral, hexahedral, or polyhedral meshing. These methods allow you to fill the volume of the geometry with different types of elements. You can also use sizing controls to adjust the element size based on various criteria such as curvature, proximity, or relevance 1.
- To ensure the quality of your mesh, you need to check some parameters such as aspect ratio, skewness, orthogonality, smoothness, and Jacobian. These parameters indicate how well the elements represent the geometry and how suitable they are for the solver. You can use Ansys Meshing tools such as statistics, histogram, or mesh metrics to evaluate these parameters and identify any problematic areas in your mesh 1.
- To perform a transient structural analysis in Ansys Mechanical, you need to define the material properties, boundary conditions, loads, and time steps for your model. You also need to select the appropriate solver settings and options for your analysis type and goals. You can use Ansys Mechanical tools such as solution information, convergence plots, or result tracking to monitor the progress and accuracy of your solution 3.
The difference between structured and unstructured mesh is mainly in the way the elements are connected and arranged in the mesh. A structured mesh is a regular lattice, such as an array, with implied connectivity between elements. A structured mesh has orthogonal quadrilateral (2D) or hexahedral (3D) elements that are easy to identify and access. A structured mesh is more efficient and accurate, but it is harder to generate for complex geometries 1.
An unstructured mesh is a mesh with general connectivity (GCON) whose structure is arbitrary and therefore the connectivity of elements must be defined and stored. An unstructured mesh has non-orthogonal elements, such as triangles (2D) and tetrahedra (3D), that are more flexible and can conform to any desired geometry. An unstructured mesh is more easy to generate, but it may require more elements and computational resources 2.
I hope this answer helps you understand the difference between structured and unstructured mesh. If you want to learn more about the types of mesh and how to use them in Ansys Workbench, you can check out these resources:
- Meshing in FEA: Structured vs Unstructured meshes | OnScale
- Types of mesh - Wikipedia
- Mesh generation - Wikipedia
- What is the difference between structured mesh and unstructured mesh …
- What is Mesh and what are the types of Meshing - Prescient
Structured meshes are meshes with a regular and structured arrangement of cells, which are typically quadrilaterals or hexahedra in two and three dimensions, respectively. The sides of the cells are usually parallel, and the grid spacing is uniform. Structured meshes have the following advantages and disadvantages 1:
- Advantages:
- They are easier to generate, as the grid cells have a regular and structured arrangement that can be generated automatically.
- They are faster to solve, as the computation of the finite element solution can be simplified.
- They are more accurate in simple geometries, where the regularity of the mesh can help to reduce errors caused by distorted cells.
- They have lower computational cost, due to the regularity of the mesh.
- Disadvantages:
- They have limited flexibility, as the regularity of the mesh can limit its ability to conform to complex geometries or regions with curved boundaries.
- They have increased computational cost in regions where the solution is smooth, as the uniform spacing of nodes in structured meshes can lead to an excessive number of nodes in those regions.
- They are less accurate with complex geometries, as the regularity of the mesh may not be able to conform to the shape of the domain.
- Advantages:
Unstructured meshes are meshes with an irregular arrangement of grid cells, which can be any shape and size. The cells can be quadrilaterals and triangles in two dimensions, hexahedra and tetrahedra in three dimensions, and the grid spacing is not uniform. Unstructured meshes have the following advantages and disadvantages 1:
- Advantages:
- They are more flexible, as they can conform to any desired geometry with localized resolutions.
- They can handle complex geometries more easily, as they can fill the volume of the geometry with different types of elements.
- They can have arbitrary positions, as they do not depend on a predefined grid structure.
- Disadvantages:
- They require more memory, as they need to store more information about the connectivity and coordinates of each node and element.
- They are slower to solve, as they require more complex algorithms and computations to solve the finite element equations.
- They may have lower accuracy, as they may have distorted or poorly shaped elements that can affect the quality of the solution.
- Advantages:
I hope this answer helps you understand the advantages and disadvantages of structured and unstructured meshes. If you want to learn more about how to use them in Ansys Workbench, you can check out these resources:
- Meshing in FEA: Structured vs Unstructured meshes | OnScale
- Faster FEA: Structured vs Unstructured Meshing - Paulin Research Group
- [What is Mesh and what are the types of Meshing - Prescient]
- Open Ansys Workbench and create a new project. Drag and drop the Geometry component from the Toolbox to the Project Schematic. Double-click on the Geometry cell to launch Ansys SpaceClaim.
- In Ansys SpaceClaim, import or create your geometry that you want to mesh. You can use various tools to modify, repair, or simplify your geometry as needed. You can also create named selections for different parts or surfaces of your geometry that you want to apply different mesh settings later. Save and update your geometry in Ansys Workbench.
- Drag and drop the Mesh component from the Toolbox to the Project Schematic. Connect the Geometry cell to the Mesh cell. Double-click on the Mesh cell to launch Ansys Meshing.
- In Ansys Meshing, you can see your geometry in the Graphics window and the Tree Outline window. You can use various tools to manipulate the view of your geometry, such as zoom, pan, rotate, or fit. You can also use the Display Style toolbar to change the display mode of your geometry, such as wireframe, shaded, or transparent.
- To create an unstructured mesh, you can use methods such as tetrahedral, hexahedral, or polyhedral meshing. These methods allow you to fill the volume of the geometry with different types of elements. You can access these methods from the Mesh toolbar or the Tree Outline window.
- To apply a tetrahedral mesh method, select Tetrahedrons from the Mesh toolbar or right-click on Mesh in the Tree Outline window and select Insert > Method > Tetrahedrons. In the Details of Tetrahedrons window, you can select the Geometry that you want to apply this method to. You can also change the Element Size and Growth Rate settings to control the size and distribution of the elements.
- To apply a hexahedral mesh method, select Hex Dominant from the Mesh toolbar or right-click on Mesh in the Tree Outline window and select Insert > Method > Hex Dominant. In the Details of Hex Dominant window, you can select the Geometry that you want to apply this method to. You can also change the Element Size and Growth Rate settings to control the size and distribution of the elements.
- To apply a polyhedral mesh method, select Polyhedral from the Mesh toolbar or right-click on Mesh in the Tree Outline window and select Insert > Method > Polyhedral. In the Details of Polyhedral window, you can select the Geometry that you want to apply this method to. You can also change the Element Size and Growth Rate settings to control the size and distribution of the elements.
- To generate the mesh, click on Generate Mesh from the Mesh toolbar or right-click on Mesh in the Tree Outline window and select Generate Mesh. You can see your mesh in the Graphics window and check its statistics in the Statistics window. You can also use various tools to evaluate and improve your mesh quality, such as statistics, histogram, or mesh metrics.
- To export your mesh, click on Update Project from the Mesh toolbar or right-click on Mesh in the Tree Outline window and select Update Project. You can also save your mesh as a file by clicking on File > Export > Mesh.
I hope this answer helps you create an unstructured mesh in Ansys Meshing. If you want to learn more about how to use Ansys Meshing, you can check out these resources:
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