Why fea is needed

The mesh is programmed to contain all the material, properties, and other factors that constitute the structure and determine how it will react to certain load conditions, such as thermal, gravitational, pressure, or point loads.

The nodes are then assigned a density throughout the material, all depending on the stress levels anticipated in a certain area. In general, points with more stress such as corners of a building or contact points on a car frame will usually have a higher node density than those with little or no stress.

The importance of FEA lies in its ability to take a complex design and offer insight into its efficiency and robustness of the design. With FEA, engineers can gain early information on system failures and improper design techniques. The finite element method involves constructing a digital mesh of the design.

This design comprises of innumerable smaller elements. We can then map data for each of the finite elements. This breaks a large-scale equation down into multiple, smaller equations for each element. These equations then combine to give a picture of the dynamics acting on the design.

The equations usually required for this kind of calculation are often partial differential equations. In FEA, engineers can tweak the prediction accuracy of a complicated domain to maintain focus on the core problem. Login Login. Members' Portal. Click here to see our latest technical engineering podcasts on YouTube.

Partial Differential Equations As mentioned above, finite element analysis is used to solve partial differential equations, but some PDEs are more suitable. Reduced Integration in Finite Element Analysis Most finite element FE codes find a solution by calculating the element stiffness matrix and then inverting it to solve for the displacements in the element Element Type for Welded Structure Finite Element Modelling Finite element codes usually provide both 'structural' and 'continuum' elements For more information please email: contactus twi.

Eigenfrequencies and eigenmodes of a structure due to vibration can be simulated using modal analysis. The peak response of a structure or system under a given load can be simulated with harmonic analysis. An example is the start of an engine.

As discussed earlier in the section on PDEs, traditional FEM technology has demonstrated shortcomings in modeling problems related to fluid mechanics, wave propagation, etc. Several improvements have been made over the last two decades to improve the solution process and extend the applicability of finite element analysis to a wide genre of problems. Some of the important ones still being used include:.

The Bubnov-Galerkin method requires continuity of displacements across elements. Problems like contact, fracture, and damage, however, involve discontinuities and jumps that cannot be directly handled by Finite Element Methods.

To overcome this shortcoming, XFEM was born in the s. XFEM works through the expansion of the shape functions with Heaviside step functions. Extra degrees-of-freedom are assigned to the nodes around the point of discontinuity so that the jumps can be considered. It combines the features of traditional FEM software and meshless methods. Shape functions are primarily defined in the global coordinates and further multiplied by partition-of-unity to create local elemental shape functions.

One of the advantages of GFEM is the prevention of re-meshing around singularities. In several problems, like contact or incompressibility, constraints are imposed using Lagrange multipliers. These extra degrees of freedom arising from Lagrange multipliers are solved independently. The equations are solved like a coupled system. This is not the same as doing h- and p- refinements separately. When automatic hp-refinement is used, and an element is divided into smaller elements h-refinement , each element can have different polynomial orders as well.

In addition, it has also shown promise in bending and incompressible problems which are commonly observed in most material processes. Here additional constraints are added to the weak form that include a penalty parameter to prevent interpenetration and terms for other equilibrium of stresses between the elements.

The FEA software component of SimScale enables you to virtually test and predict the behavior of structures and hence solve complex structural engineering problems subjected to static and dynamic loading conditions. The FEA simulation platform uses scalable numerical methods that can calculate mathematical expressions that would otherwise be very challenging due to complex loading, geometries, or material properties.

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Strictly Necessary Cookie should be enabled at all times so that we can save your preferences for cookie settings. If you disable this cookie, we will not be able to save your preferences. This means that every time you visit this website you will need to enable or disable cookies again. Sign Up. Figure 1: FEA Simulation of a piston rod.

The different colors are indicators of variable values that help predict mechanical behavior. Figure 2: Temperature distribution along a bar length with linear approximation between the nodal values.