Product: ABAQUS/Standard
B21 B21H B22 B22H B23 B23H B31 B31H B32 B32H B33 B33H
C3D4 C3D6 C3D8 C3D10 C3D15 C3D20
CAX3 CAX4 CAX4R CAX6 CAX8 CAX8R
CPEG3 CPEG3H CPEG4 CPEG4H CPEG4R CPEG4RH CPEG4I CPEG4IH CPEG6 CPEG6H CPEG8 CPEG8H CPEG8R CPEG8RH
CPE3 CPE3H CPE4 CPE4H CPE4R CPE4RH CPE4I CPE4IH CPE6 CPE6H
CPE8 CPE8H CPE8R CPE8RH
CPS3 CPS4 CPS4R CPS6 CPS8 CPS8R
ELBOW31 ELBOW31B ELBOW31C ELBOW32
M3D3 M3D4 M3D4R M3D6 M3D8 M3D8R M3D9 M3D9R MASS
PIPE21 PIPE21H PIPE31 PIPE31H PIPE32 PIPE32H ROTARYI PIPE22 PIPE22H
S3R S4 S4R S4R5 S8R S8R5 S9R5 STRI3 STRI65
The output variables XC, UC (URC), VC (VRC), HC, HO, RI, MASS, and VOL give the equivalent rigid body motion for any general dynamic motion. These output variables are valid only for *DYNAMIC analyses. The accuracy of these output variables is verified with a test suite that encompasses all elements that have mass and/or rotary inertia.
The equivalent rigid body motion output variables are specified in *EL PRINT and/or *EL FILE options. They can only be requested when using the *DYNAMIC procedure. These variables are considered whole element set variables, meaning that the quantity requested is summed over the element set specified. If no element set is specified, the quantity is summed over the entire model. The element set specified may contain elements which do not have mass (SPRINGs, DASHPOTs, etc.), but these elements will be ignored during the summation process. Specifying an element set in which all elements have no mass will elicit a warning message from ABAQUS.
All of the verification problems below impose a rigid body motion on single element models. Each input file contains separate and distinct single element meshes corresponding to the many specific elements within that element category. For instance, the xrbmcpes.inp input file tests all of the CPE type elements and contains single element meshes for the CPE3, CPE4, CPE4R, CPE6, CPE8, CPE8R elements (and hybrid versions of all these elements). Most of the problems impose a planar 90° rotation about the z-axis; the three-dimensional continuum problem imposes an oblique rotation. Separate *EL FILE output requests are given for each element set in the model.
These verification problems all impose a simple rigid body motion. In all cases the magnitude of the rigid body output variables should agree with the imposed motion. For some problems (such as those with an imposed constant velocity) the expected magnitudes of the output variables can be calculated directly from the imposed motion. In other problems the expected output variable magnitudes can be calculated from the imposed motion and the element geometry.
Tests all axisymmetric elements, including axisymmetric shells. A constant z-velocity is imposed (there is no valid rotation in axisymmetric problems).
Tests all beam elements (excludes open section beams). A rigid 90° rotation is imposed about the z-axis.
Uses results of xrbmbeam.inp to verify the *POST OUTPUT option.
Tests all three-dimensional truss elements.
Tests all three-dimensional continuum elements. A rigid rotation is imposed about the direction (.707, .707, 0.0).
Tests all generalized plane strain elements.
Tests all plane strain elements.
Restart of xrbmcpes.inp. Tests *RESTART without END STEP.
Tests all plane stress elements.
Tests all elbow elements.
Tests the mass element. A constant x-velocity is imposed. Tests are done with and without the *TRANSFORM option.
Tests all membrane elements. A rigid rotation is imposed about the z-axis. Shell elements overlay the membranes for stability purposes.
Four separate tests of the rotary inertia element. The first test uses a constant velocity. The second imposes both a translation and rotation. The third is similar to the second, but adds the use of the *TRANSFORM option. The fourth test is similar to the second, but adds both *TRANSFORM and *ORIENTATION.
Tests all shell elements. A rigid 90° rotation is imposed about the z-axis.
This model consists of an axisymmetric solid and a three-dimensional beam element. A constant y-velocity is imposed. A rigid body output request is made for the axisymmetric element, and another is made for the whole model. This tests the format of the printed output. The axisymmetric printed output is limited to specific directions. With the addition of a three-dimensional beam, the whole model output must be given for all directions.
This test is similar to xrbmaxb1.inp, but the order of the element generation is reversed. The printed output should be identical to the output for xrbmaxb1.inp.
This test is similar to xrbmaxb1.inp but uses a two-dimensional beam element. Again, the purpose is to compare the format of the printed output for the axisymmetric element to the output for the whole model.
This model consists of a spring and a beam. A rigid body variable request is made for an element set containing only the spring. This should trigger a warning message from ABAQUS. Another output request is made for the whole model. The output should agree with the imposed rigid rotation of the beam element.