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