Hybrid elements are intended primarily for use with incompressible and almost incompressible material behavior. When the material response is incompressible, the solution to a problem cannot be obtained in terms of the displacement history only, since a purely hydrostatic pressure can be added without changing the displacements. Hybrid elements have more internal variables than their nonhybrid counterparts and are slightly more expensive computationally.

Modified parabolic tetrahedral elements result in improved computational performance for components involved in contact interactions.

Abaqus uses numerical techniques to integrate various quantities over the volume of each element, thus allowing complete generality in material behavior. Using Gaussian quadrature for most elements, Abaqus evaluates the material response at each integration point in each element. Some elements in Abaqus can use full or reduced integration, a choice that can have a significant effect on the accuracy of the element for a given problem. Reduced integration uses a lower-order integration to form the element stiffness. The mass matrix and distributed loadings use full integration. Reduced integration reduces running time, especially in three dimensions.

Linear hexahedral elements with incompatible modes perform much better in pure bending applications than the standard linear hexahedron but with much less computational expense than parabolic elements.

Continuum shell elements resemble three-dimensional solid elements in that they model an entire three-dimensional body, and their thickness is determined from the element nodal geometry. However, continuum shell elements are formulated so that their kinematic and constitutive behavior is similar to conventional shell elements. See Assigning Continuum Shell Properties to Solids for more information.

Gasket elements are three-dimensional solid elements used to model thin sealing components that can be used between structural components in an assembly. See Assigning Gasket Properties to Solids for more information.

Membrane elements are two-dimensional elements that transmit in-plane forces only. Membrane elements do not transmit moments, and they have no bending stiffness. See Assigning Membrane Properties to Surfaces for more information.