Writing element matrix output records

This problem contains basic test cases for one or more Abaqus elements and features.

This page discusses:

ProductsAbaqus/Standard

Elements tested

  • B21
  • C3D8
  • DS3
  • DS4
  • S4
  • S4R
  • S4R5
  • S8R

Features tested

The output and input of element matrices are tested.

Problem description

These tests verify that the matrices written out by the element matrix output procedure are valid and that they can be input into an analysis and used again. The validity of the element matrices is tested by an analysis that uses the matrices to solve a linear problem.

Results and discussion

xemob21o.inp, xemob21u.inp

The maximum displacement in this problem is 332.04. The computed displacements in both problems match this value, and the displacements at the other nodes match as well.

xemoc38o.inp, xemoc38u.inp

The maximum displacement of −2.0E−4 occurs at nodes 3 and 7 in this problem. Both runs have identical displacement fields.

xemods3o.inp, xemods4u.inp

The temperature variation through the plate in this example is the same at all nodes. The bottom has a temperature of 0.0, the middle temperature is 746.0, and the top has a temperature of 994.7. The results for both cases are the same.

xemods4o.inp, xemods4u.inp

The temperature variation through the plate in this example is the same at all nodes. The bottom has a temperature of 0.0, the middle temperature is 746.2, and the top has a temperature of 994.69. The results for both runs are the same.

xemos45o.inp, xemos45u.inp

The maximum displacement of −8.6667E−5 occurs at node 4 in both problems. However, the problem which uses the previously computed matrices is missing the rotation at node 1. This extra degree of freedom in the first run is a result of special procedures that activate the rotation if a boundary or loading condition is applied there. The precomputed element stiffness matrix does not have this capability.

xemos4o.inp, xemos4u.inp

The maximum displacement of −8.6667E−5 occurs at node 4 in both problems. Both runs have identical displacement fields, including the rotations. There is no conditional activation of rotation degrees of freedom with the S4 elements as there is with the S4R5 elements.

xemos4ro.inp, xemos4ru.inp

The maximum displacement of −8.6667E−5 occurs at node 4 in both problems. Both runs have identical displacement fields, including the rotations. There is no conditional activation of rotation degrees of freedom with the S4R elements, as there is with the S4R5 elements.

xemos8ro.inp, xemos8ru.inp

The maximum displacement of −3.6376 occurs at node 89. Both runs have the same displacements.

Input files

Output of element matrix:
xemob21o.inp

Cantilever made up of five B21 elements with a point load at the end. A static step is used to test the matrices.

xemoc38o.inp

One C3D8 element with distributed and concentrated loads. A static step is used to test the matrix.

xemods3o.inp

One DS3 element with a distributed flux. A steady-state heat transfer step is used to test the matrix.

xemods4o.inp

One DS4 element with a distributed flux. A steady-state heat transfer step is used to test the matrix.

xemos45o.inp

One S4R5 element with concentrated loads. A static step is used to test the matrix.

xemos4o.inp

One S4 element with concentrated loads. A static step is used to test the matrix.

xemos4ro.inp

One S4R element with concentrated loads. A static step is used to test the matrix.

xemos8ro.inp

One S8R element with distributed loads. A static step is used to test the matrix.

Input of element matrix:
xemob21u.inp

Cantilever made up of five B21 elements with a point load at the end. A static step is used to test the matrices.

xemoc38u.inp

One C3D8 element with distributed and concentrated loads. A static step is used to test the matrix.

xemods3u.inp

One DS3 element with a distributed flux. A steady-state heat transfer step is used to test the matrix.

xemods4u.inp

One DS4 element with a distributed flux. A steady-state heat transfer step is used to test the matrix.

xemos45u.inp

One S4R5 element with concentrated loads. A static step is used to test the matrix.

xemos4u.inp

One S4 element with concentrated loads. A static step is used to test the matrix.

xemos4ru.inp

One S4R element with concentrated loads. A static step is used to test the matrix.

xemos8ru.inp

One S8R element with distributed loads. A static step is used to test the matrix.