VUAMP

Features tested

User subroutine VUAMP to define amplitudes.

Problem description

The finite element models for most test cases consist of simple linear truss or connector elements. User subroutine VUAMP is used to define amplitudes that are subsequently used to drive certain loading options such as concentrated loads, boundary conditions, and connector motions. In most cases the VUAMP user-defined amplitudes are simple linear ramps. The results from the analyses are compared against reference results obtained using identical models with equivalent tabular amplitude definitions.

User subroutine VUAMP can make use of sensor definitions and state variables, and a number of tests exercise these features. In certain tests (such as when a user-defined amplitude is used to drive the displacement boundary condition) the user subroutine may compute derivatives, integrals, and second derivatives of the amplitude function being defined. In addition, amplitude properties can be defined on the data line, which allows changes to the amplitude definition without modifing the user subroutine.

Results and discussion

The verification consists of comparing the results obtained from the model using user-defined amplitudes with the corresponding model using tabular amplitudes. The results match very well, as expected.

Input files

vuamp_ramp_simple_cload.inp: Concentrated load force scaled by an amplitude defined in user subroutine VUAMP in vuamp_ramp_simple.f.
vuamp_ramp_simple_bcdisp.inp: Displacement boundary condition scaled by an amplitude defined in user subroutine VUAMP in vuamp_ramp_simple.f.
vuamp_ramp_simple_restart.inp: Displacement boundary condition in a restart analysis scaled by an amplitude defined in user subroutine VUAMP in vuamp_ramp_simple.f.
vuamp_ramp_simple_bcvel.inp: Velocity boundary condition scaled by an amplitude defined in user subroutine VUAMP in vuamp_ramp_simple.f.
vuamp_ramp_simple_bcvel_props.inp: Velocity boundary condition scaled by an amplitude defined in user subroutine VUAMP in vuamp_ramp_simple_props.f.
vuamp_ramp_simple_bcacc.inp: Acceleration boundary condition scaled by an amplitude defined in user subroutine VUAMP in vuamp_ramp_simple.f.
vuamp_ramp_simple_connmot.inp: Displacement connector motion scaled by an amplitude defined in user subroutine VUAMP in vuamp_ramp_simple.f.
vuamp_ramp_state_connmot_props.inp: Displacement connector motion scaled by an amplitude defined in user subroutine VUAMP in vuamp_ramp_simple_props.f.
vuamp_ramp_simple.f: User subroutine VUAMP defining a simple ramp amplitude using state variables.
vuamp_ramp_simple_props.f: User subroutine VUAMP defining a simple ramp amplitude using state variables. The amplitude property, as defined, acts as the slope of the ramp function.
vuamp_ramp_state_cload.inp: Concentrated load force scaled by an amplitude defined in user subroutine VUAMP in vuamp_ramp_state.f.
vuamp_ramp_state_connmot.inp: Displacement connector motion scaled by an amplitude defined in user subroutine VUAMP in vuamp_ramp_state.f.
vuamp_ramp_state.f: User subroutine VUAMP defining a simple ramp amplitude using state variables.
vuamp_ramp_state_props.f: User subroutine VUAMP defining a simple ramp amplitude using state variables. The amplitude property, as defined, acts as the slope of the ramp function.
vuamp_deriv_bcdisp.inp: Displacement boundary condition scaled by an amplitude defined in user subroutine VUAMP in vuamp_deriv.f.
vuamp_deriv.f: User subroutine VUAMP defining cubic function amplitude which also computes derivatives.
vuamp_ramp_sensor_connmot.inp: Displacement connector motion scaled by an amplitude defined in user subroutine VUAMP in vuamp_ramp_sensor.f.
vuamp_ramp_sensor.f: User subroutine VUAMP defining a simple ramp amplitude using sensors.
vuamp_manysensors.inp: Displacement connector motion scaled by an amplitude defined in user subroutine VUAMP in vuamp_manysensors.f.
vuamp_manysensors.f: User subroutine VUAMP defining a simple ramp amplitude using sensors.