UTEMP, UFIELD, UMASFL, and UPRESS

This set of tests verifies that temperature and field variable values are properly transferred to a structure when the values are set using user subroutines. These tests are modifications of the tests described in Defining temperature, field variable, pressure stress, and pore fluid pressure values. Wherever results files were used in those tests, most have been replaced here with user subroutines. The structure being analyzed is a cantilevered truss made up of 10 T3D2 elements.

The tests are as follows:

utmpfvs1.inp

This file tests setting temperature and more than one field variable using user subroutines. The variation of temperature and all three field variables are linear with time as follows:

	Initial value	Final value
Temperature	100	200
Field variable 1	100	200
Field variable 2	200	250
Field variable 3	100	200

utmpfvs2.inp

This file tests setting a field variable from a user subroutine without temperature being present in the problem. This is an important test because of the way that temperatures and field variables are stored internally. The field variable varies linearly with time, as follows:

	Initial value	Final value
Field variable	100	200

(The problem that is analogous to test xtfvtrs3.inp in Defining temperature, field variable, pressure stress, and pore fluid pressure values is omitted, since this analysis would not test any features that were not already covered by the other tests in this section.)

utmpfvs4.inp

This is a three-step problem involving temperature and one field variable. In the first step an amplitude curve is used to set temperature to 200 and the field variable to 250. In the second step temperature and the field variable are set twice: first, values are read from results files, and then the user subroutines multiply all values by two. This results in ramping the temperature to 400 and the field variable to 500 over the step. The results files used are as follows:

xtfvtrt1.fil $\Rightarrow$ Temperature

xtfvtrt2.fil $\Rightarrow$ Field variable 1

(These two heat transfer problems are described further in Defining temperature, field variable, pressure stress, and pore fluid pressure values.) In the third step both the temperature and the field variable are reset to their initial conditions.

The following must be confirmed by this test:

• The user subroutine must mesh smoothly with other methods of setting temperature and field variables used in other steps.

• The user subroutine must have access to values set from a results file and must be able to modify those values.

• If temperature or a field variable is set by data line input and then modified by a user subroutine within the same step, the values given on the data lines must be ignored.

• The variable KSTEP must be available for use in both user subroutines.

utmpfvsr.inp

This analysis restarts utmpfvs4.inp from the third step. Temperature and the field variable are both set using user subroutines as follows:

	Initial value	Final value
Temperature	0	100
Field variable	0	50

utmpfvsn.inp

This file tests setting all of the field variables simultaneously in user subroutine UFIELD. The final results are the same as those obtained in utmpfvs1.inp.

This set of tests verifies the use of user subroutines UTEMP and UFIELD in conjunction with composite structural shells. These tests are modifications of the tests described in Defining temperature, field variable, pressure stress, and pore fluid pressure values. Values that were obtained from results files in those problems are set here with user subroutines. A three-layered composite shell with a prescribed temperature or field variable profile through the cross-section is analyzed. Three temperature points and five section integration points are used for each layer. The temperature and field variables are assigned to these five points through a linear interpolation of the three values available per layer from the user subroutine. The results of these analyses verify that this interpolation is correct.

The user subroutines are tested for 4-node shells and 8-node shells.

These tests verify that field variables and mass flow rates are properly transferred to a structure during heat transfer and coupled temperature-displacement analyses. These tests are modifications of the tests described in Thermal properties and GAPCON. The tests are cases of uniform one-dimensional heat flux using three-dimensional elements. Consequently, the temperature results are identical for all nodes located at a particular plane along the direction of heat flow. In all cases a steady-state heat transfer analysis is performed in several increments. Values of predefined field variables or mass flow rates vary during the solution, which in turn influences the conductivity across the interface and, thus, the solution.

These tests verify that equivalent pressure stresses are transferred properly to a structure during a mass diffusion analysis. The tests are cases of uniform one-dimensional mass diffusion using three-dimensional elements. Consequently, the concentration results are identical for all nodes located at a particular plane along the diffusion direction.