Category: Theory
What is Work Hardening ?
Work hardening or strain hardening is a process through which the yield strength and hardness of a metal are increased by plastic deformation. Consider the hypothetical stress strain curve shown below for a metallic specimen:
FEA Theory – Simplified in Seven Points
1) The underlying equation for structural FEA is {F}= [K]*{X} Where {F} is the input load vector and [K] is the global stiffness matrix. {X} is the unknown displacement vector which is solved for at each node in the model. 2) The above gives displacement results only at the nodes. There is no information yet…
Converting Total Strain into Elastic and Plastic Components
This spreadsheet lets you convert total strain into its elastic and plastic components. You have to input values for Young’s Modulus, Total Strain and Total Stress – Make sure that the Young’s Modulus and Total Stress have the same units: Strain Converter Stress Total Strain Elastic Strain Plastic Strain 0 0.00000 0.00000 0.00000 10,443 0.00049…
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What are integration points in FEA?
An FE solver computes displacement and force results at the element nodes . The shape function is used to interpolate the nodal results onto the interior of the element. Unlike displacements and forces, strains and stresses are not computed at the nodes. They are computed at specific locations called “integration points” within the element. Integration…
What is a Degree of Freedom?
Degrees of freedom refer to the parameters of a node that may vary independently of each other. In a structural analysis, a node may have up to six degrees of freedom – Three translations and three rotations (one each in X, Y, and Z direction). 3D elements have three DOF – Translations in X, Y,…
Linear vs Quadratic FE Elements
A linear element, or a lower order element is characterized by a linear shape function. The displacements of the mesh region between the nodes vary linearly with the distance between the nodes. Linear elements do not capture bending. A quadratic element, or a higher order element utilizes a non-linear shape function. The displacements between the…
What is a Shape Function?
A Finite Element mesh is the discretization of a continuous geometry into finite parts (elements). An FE solver calculates the displacements at individual nodes of the elements. We are also interested in what happens in the volume (or area for 2-D elements) of the element. But this information is not directly available from the nodal…
