When building a mesh for FEA, there are different types of elements that can be used: - Line elements (https://fea-solutions.co.uk/line-elements/). - Surface elements (https://fea-solutions.co.uk/surface-elements/), e.g. plate or shell elements. - Solid elements (https://fea-solutions.co.uk/solid-elements/), also called volume elements or 3D elements. Because the mathematical model used for line elements consider...
When using solid elements in FEA (https://fea-solutions.co.uk/solid-elements/), they can be found to be unrealistically stiff when evaluating bodies which are subject to bending loads. This results in unrealistic low deflections, and consequently in unrealistic low stresses. This happens because in Continuum Mechanics, which is the underlying...
For any FEA model, the results have to be validated. There are different methods how do this: - Plausibility check - Comparison with hand calculations - Mesh quality check - Comparison with test data The first and most important step for FEA validation is the plausibility check. This is to...
Verification and Validation (V&V) are procedures that are used to check that a process meets the requirements and that it meets its intended purpose. Applying these procedures to FEA, there are commonly used definitions for both Verification and Validation, and what they are used for: -...
When referring to convergence in FEA, it could mean one of two things: - Mesh Convergence (https://fea-solutions.co.uk/mesh-convergence/) - Analysis Convergence Analysis convergence is the calculation of the equilibrium of externally applied forces to internally developed forces in a non-linear analysis (https://fea-solutions.co.uk/non-linear-behaviour/). In a non-linear analysis, loads are gradually applied...
When referring to convergence in FEA, it could mean one of two things: - Mesh Convergence - Analysis Convergence (https://fea-solutions.co.uk/analysis-convergence/) Mesh convergence determines how many elements are needed in a model so that the FEA results, in particular the peak stresses, are not affected by further refining the...
As FEA results are calculated at the nodes (https://fea-solutions.co.uk/nodal-stress-calculation/), they depend on the quality of the mesh (https://fea-solutions.co.uk/fea-terminology/). To achieve a high quality mesh, it must be refined in areas of small geometric details or high curvature. Thus, the geometric effect on results can be...
When meshing a geometry in FEA, the resulting elements (https://fea-solutions.co.uk/fea-terminology/) used are defined not only by their type (https://fea-solutions.co.uk/fea-element-types/), but also by their order. The order of element describes how many nodes are on an element edge. 1st order elements have nodes only at the...
A stress singularity is a location where the stress is theoretically infinite. As stress is equal to force/area, stress singularities occur where the area is 0. There are some common places for stress singularities to occur: Point loads or point supports Sharp inside corners A stress...
Stresses of a FE analysis are calculated for elements at their integration points (https://fea-solutions.co.uk/nodal-stress-calculation/). To come up with a nodal stress, the common procedure is to calculate the average of the extrapolated element stresses at that node. There are two methods for stress averaging: - Topological method -...