Change Command and Material Properties

Yes you can change the material after a CHANGE command.

Yes you can change the material after a CHANGE command.

How can I change the material after the CHANGE command? I've tried a few things, but I've received errors or warnings each time. Additionally I need to change the support conditions after the CHANGE command? Any recommendations on how to do that? Here's the input file I'm using on a small test model:

STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 20-May-15
END JOB INFORMATION
INPUT WIDTH 79
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0; 2 25 0 0; 3 0 12.5 0; 4 12.5 12.5 0; 5 25 12.5 0; 6 0 25 0;
7 12.5 25 0; 8 25 25 0; 9 0 37.5 0; 10 12.5 37.5 0; 11 25 37.5 0;
MEMBER INCIDENCES
1 1 3; 2 4 1; 3 2 4; 4 5 2; 5 3 4; 6 4 5; 7 3 6; 8 4 6; 9 8 4; 10 8 5; 11 6 7;
12 7 8; 13 6 9; 14 10 6; 15 8 10; 16 11 8; 17 9 10; 18 10 11;
*
DEFINE MATERIAL START
ISOTROPIC STEEL
E 4.176e+006
POISSON 0.3
DENSITY 0.489024
ALPHA 6e-006
DAMP 0.03
TYPE STEEL
*
* Material property assigned to all vertical braces for expected strength analysis
ISOTROPIC THERMAL_BRACE
E 4.176
POISSON 0.3
DENSITY 0.489024
ALPHA 6
DAMP 0.03
END DEFINE MATERIAL
*
MEMBER PROPERTY AMERICAN
5 6 11 12 17 18 TABLE ST W12X79
1 4 7 10 13 16 TABLE ST W14X120
2 3 TABLE ST HSSP8.625X0.5
8 9 TABLE ST HSSP7.500X0.5
14 15 TABLE ST HSSP6.875X0.5
*
CONSTANTS
MATERIAL THERMAL_BRACE MEMB 2 3 8 9 14 15
MATERIAL STEEL MEMB 1 4 TO 7 10 TO 13 16 TO 18
SUPPORTS
1 2 FIXED BUT MY MZ
3 5 6 8 9 11 FIXED BUT FY MX MY MZ
MEMBER RELEASE
2 3 5 8 9 11 14 15 17 START MY MZ
2 3 6 8 9 12 14 15 18 END MY MZ
*
*
LOAD 1 LOADTYPE None TITLE THERMAL LOAD CASE FOR EXPECTED STRENGTH ANALYSIS
TEMPERATURE LOAD
14 TEMP -337.7
15 TEMP 272.62
8 TEMP 289.029
9 TEMP -338.131
2 TEMP -338.066
3 TEMP 311.021
*
PERFORM ANALYSIS
CHANGE
*
* Change material properties for all vertical braces back to steel
Constants
MATERIAL steel MEMB 2 3 8 9 14 15
*
* Change the lateral supports to prevent out of plane displacment only.
SUPPORTS
3 5 6 8 9 11 FIXED BUT FX FY MX MY MZ
*
LOAD 2 LOADTYPE None TITLE DEAD LOAD
MEMBER LOAD
5 6 11 12 17 18 UNI GY -1
*
LOAD 3 LOADTYPE None TITLE WIND LOAD
MEMBER LOAD
1 7 13 UNI GX 1
*
*
PERFORM ANALYSIS
FINISH

You may try to use these options as shown in the attached file.

6663.a2.std

Thanks for the response, but I received a few errors message when I opened that file.

I think I found a solution. After a CHANGE command you have to create a new material property for the braces. You can then assign this material property to braces. For the supports, you have to add supports to all nodes that at some point will have supports applied to them (for expected strength load case apply lateral supports to nodes, but then for dead load case these same nodes need supports too, but the supports would be completely released ie fixed but fx fy fz mx my mz).