VUEL

Features tested

User subroutine VUEL to define the element mass matrix, the force vector, and the stable time increment.

Problem description

The finite element model for most test cases consists of linear truss or spring elements defined using user subroutine VUEL. In most cases the results from the analysis are compared against reference results obtained using an identical model with Abaqus elements T3D2 and CONN3D2. A truss element lying along the global X-axis is defined in a user subroutine. This user element is used in a model with single or multiple user elements subjected to concentrated loads. The results are then compared with models using T3D2 elements.

The field and temperature-dependent variation in material properties can be defined in the user element. To test this capability, a truss element is defined with a linear variation of elastic modulus with temperature and field variables. The results are then compared with temperature and field variable dependencies in properties in a T3D2 element.

A number of uncoupled linear spring elements are defined using the user subroutine interface. Both two-dimensional and three-dimensional elements are tested. The following features are tested with three-dimensional spring elements: an element with more than two nodes, an element with degrees of freedom ordered in a nonstandard way, and an element with a different number of degrees of freedom at its nodes.

User-defined elements with acoustic degrees of freedom and with heat transfer capabilities are also tested.

Results and discussion

The verification consists of comparing the results obtained from the model using user-defined elements with the corresponding model using regular Abaqus elements. The results are as expected.

Input files

vuel_truss_3d_1el.inp: Analysis of a one-element truss defined in user subroutine VUEL in vuel_truss.f.
vuel_truss_3d_1el_dload.inp: Analysis of a one-element truss defined in user subroutine VUEL in vuel_truss.f using user-coded external loads.
vuel_truss_3d_250el.inp: Analysis of multiple truss elements connected in series; the truss element is defined in user subroutine VUEL in vuel_truss.f.
vuel_truss.f: User subroutine VUEL defining a three-dimensional truss element along the global x-direction.
abq_truss_3d_1el.inp: Analysis of a one-element truss defined using the T3D2 element; reference solution for vuel_truss_3d_1el.inp.
abq_truss_3d_250el.inp: Analysis of multiple truss elements defined using the T3D2 element; reference solution for vuel_truss_3d_250el.inp.
vuel_truss_3d_1el_fieldvar.inp: A one-element truss with field variable-dependent material properties. The element is defined in user subroutine VUEL in vuel_truss_fieldvar.f.
vuel_truss_fieldvar.f: User subroutine VUEL defining a three-dimensional truss element with field variable-dependent material properties.
abq_truss_3d_1el_fieldvar.inp: A T3D2 element with field variable-dependent material properties; reference solution for vuel_truss_3d_1el_fieldvar.inp.
vuel_truss_3d_1el_temp.inp: A one-element truss with temperature-dependent material properties. The element is defined in user subroutine VUEL in vuel_truss_temp.f.
vuel_truss_temp.f: User subroutine VUEL defining a three-dimensional truss element with temperature-dependent material properties.
abq_truss_3d_1el_temp.inp: A T3D2 element with temperature-dependent material properties; reference solution for vuel_truss_3d_1el_temp.inp.
vuel_springs_3d_freevibx.inp: Free vibration in the global x-direction of a linear spring defined using user subroutine VUEL in vuel_springs_3d.f.
abq_connector_freevibx.inp: Free vibration in the global x-direction of a linear spring defined using connector element CONN3D2; reference solution for vuel_springs_3d_freevibx.inp.
vuel_springs_3d_freevibrotx.inp: Free rotational vibration about the global x-direction of a linear spring defined using user subroutine VUEL in vuel_springs_3d.f.
abq_connector_freevibrotx.inp: Free rotational vibration about the global x-direction of a linear spring defined using connector element CONN3D2; reference solution for vuel_springs_3d_freevibrotx.inp.
vuel_springs_3d_1el.inp: A one-element linear spring subjected to tensile loading; the element is defined using user subroutine VUEL in vuel_springs_3d.f.
vuel_springs_3d_10el.inp: Multiple linear springs subjected to tensile loading; the element is defined using user subroutine VUEL in vuel_springs_3d.f.
vuel_springs_3d.f: User subroutine VUEL defining a three-dimensional linear spring element.
vuel_springs_3d_3node.inp: A one-element linear spring with three nodes subjected to tensile loading; the element is defined using user subroutine VUEL in vuel_springs_3d_3node.f.
vuel_springs_3d_3node.f: User subroutine VUEL defining a three-dimensional linear spring element with three nodes.
vuel_springs_3d_diffDofs.inp: A one-element linear spring with a different number of degrees of freedom defined at its nodes—the first node has six degrees of freedom, whereas the second node has only three degrees of freedom; the element is defined in user subroutine VUEL in vuel_springs_3d_diffDofs.f.
vuel_springs_3d_diffDofs.f: User subroutine VUEL defining a three-dimensional spring element with a different number of degrees of freedom at its two nodes.
vuel_springs_3d_jumpDofs.inp: A one-element linear spring with degrees of freedom ordered in a nonstandard way; the first degree of freedom from all the nodes is listed first, followed by second degree of freedom from all the nodes, and so on.
vuel_springs_3d_jumpDofs.f: User subroutine VUEL defining a three-dimensional spring element with degrees of freedom ordered in a nonstandard way.
vuel_springs_2d_1el.inp: A one-element two-dimensional linear spring. The element is defined in user subroutine VUEL in vuel_springs_2d.f.
vuel_springs_2d.f: User subroutine VUEL defining a two-dimensional linear spring element.
vuel_acoustic_1el.inp: A one-element input file to test acoustic user elements defined in user subroutine VUEL in vuel_acoustic.f.
vuel_acoustic.f: User subroutine VUEL defining an acoustic element.
vuel_heat_transf_1el.inp: A one-element input file to test a heat transfer user element defined in user subroutine VUEL in vuel_heat_transf.f.
vuel_heat_transf.f: User subroutine VUEL defining a heat transfer element.

VUEL

Elements tested

Features tested

Problem description

Results and discussion

Input files