Product: ABAQUS/Explicit
This verification test consists of a set of single-element models for each element type in analyses that use the small-displacement theory (NLGEOM=NO on the *STEP option). All degrees of freedom are prescribed so that the results do not include any dynamic effects. Each element is subjected to all applicable fundamental modes of deformation. The total strains are large to show that the results are linear and remain unaffected by changes to the element's current configuration.
The material is linear elastic with a Young's modulus of 1.0 × 105, Poisson's ratio of .33, and density of 1000.
All element types tested yield the appropriate results for their applicable fundamental modes of deformation. Results for the two-dimensional truss element are illustrated here.
There are two global modes of deformation for a two-dimensional truss: longitudinal and lateral. The longitudinal mode is driven by fixing one end of the truss and prescribing a longitudinal displacement at the other. The axial stresses in the truss element as a result of longitudinal deformation for both small-displacement theory (NLGEOM=NO) and large-displacement theory (NLGEOM=YES) are shown in Figure 3.2.6–1. As the strains become large, the results diverge because the large-displacement theory accounts for the thinning of the truss as it stretches. The global lateral mode is invoked by prescribing a lateral displacement at one end of the truss element while holding all other degrees of freedom fixed. Results for the lateral case are shown in Figure 3.2.6–2. The nonlinear geometric effect is accounted for only in the large-displacement analysis. The small-displacement analysis ignores the extension of the truss due to its rotation and, therefore, sees no extensional strain due to the prescribed lateral displacements.
B21 elements.
B22 elements.
B31 elements.
B32 elements.
C3D8R elements.
C3D8R elements with *ORIENTATION.
CAX4R elements.
CAX4R elements with *ORIENTATION.
CPE4R elements.
CPE4R elements with *ORIENTATION.
CPS4R elements.
CPS4R elements with *ORIENTATION.
Dashpot elements.
M3D4R elements.
M3D4R elements with *ORIENTATION.
S4R elements.
S4R elements with *ORIENTATION.
S4R elements with the *SHELL GENERAL SECTION option.
S4R elements with the *SHELL GENERAL SECTION option and *ORIENTATION.
S4RS elements.
S4RS elements with *ORIENTATION.
S4RS elements with the *SHELL GENERAL SECTION option.
S4RS elements with the *SHELL GENERAL SECTION option and *ORIENTATION.
S4RSW elements.
S4RSW elements with *ORIENTATION.
S4RSW elements with the *SHELL GENERAL SECTION option.
S4RSW elements with the *SHELL GENERAL SECTION option and *ORIENTATION.
SAX1 elements.
SAX1 elements with the *SHELL GENERAL SECTION option.
Spring elements.
Two-dimensional truss elements.
Three-dimensional truss elements.
