FEA Elements
To carry out finite element analysis the geometry or solid we model is assigned a particular element depending on the types of loading on the part. Below mentioned are the common elements used in FEA.
2D Bar/Rod Element
Bar or Rod element can be visualized as long rods with ball joints at their ends can transmit force axially and can be defined by material and cross-section. These elements allow for translation only and no rotation therefore these elements do not bend. E.g. trusses used in structures, towers and bridges.
2D Beam Element
Beam element can transmit force axially as well as moments and can be defined by material, cross-section, area moment of inertia and torsional stiffness. These elements allow for translation and rotation at each end therefore these elements can undergo bending. E.g. beams used in steel structures.
2D Membrane Element
Membrane Elements support only translational DOF not rotational and in-plane loading. These elements will not support or transmit a moment load or stress normal to the surface. The thickness of the membrane must be small relative to its length or width. The geometry is drawn at the midplane with zero thickness shown, similar to a plate element.
2D Shell Element
Shell elements support translational DOF as well as rotational DOF. These elements are selected when plates are under out of plane loads and undergo bending. They are typically used to model structures comprised of shells such as pressure vessels, automobile bodies and ship hulls.
3D Elements
3D elements are complex models where 2D simplification is not possible. Commonly used 3D elements are brick, wedge and tetrahedron. These elements represent all 3 dimensions of model and no inputs are required.
Pressure Vessel guide 