ProductsAbaqus/StandardAbaqus/Explicit Elements tested
Features testedComputation of rigid body mass properties, repositioning of the rigid body reference node at the center of mass of the rigid body. Problem descriptionThis suite of problems tests the mass property computations of rigid bodies consisting of continuum and structural elements in Abaqus/Standard analyses and continuum, structural, and rigid elements in Abaqus/Explicit analyses. Five different rigid body geometry cases are considered:
The mass, center of mass, and rotary inertia of each rigid body are computed automatically by Abaqus to take into account the section properties and densities of each of the constituent elements. The reference node for each rigid body is located at the center of mass. The computed mass properties of rigid bodies can be verified by checking the printed quantities in the data (.dat) file. Further quantitative and qualitative verification is accomplished by performing two analyses. In the first analysis each geometry case is subjected to a concentrated force of magnitude 1.0 × 106 in the x-direction acting at the rigid body reference node. In the second analysis each geometry case is subjected to a concentrated moment of magnitude 1.0 × 108 acting about the z-axis at the rigid body reference node. Results and discussionFor each geometry case the mass and inertia properties of the rigid body are found to match their analytical values closely. In Cases 1 and 4 the application of a concentrated force at the rigid body reference node does not cause any rotation of the rigid body about the out-of-plane axis, which verifies that the reference node has been positioned at the center of mass of the rigid body. Similarly for Cases 2, 3, and 5, for the concentrated force loading, there are no rotations observed about either the global x-, y-, or z-axes. The moment loading in each case causes large rigid body rotations about the reference node. The final rotated configuration in each case is found to be consistent with the geometry of the problem and the magnitude of the applied moment. The original and final configurations of the rigid body in Case 1 for the moment load case are shown in Figure 1 and Figure 2. Input filesAbaqus/Standard analyses
Abaqus/Explicit analyses
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