EX. US-25 Analysis of a Structure with Compression-Only Members
This example demonstrates the usage of compression-only members. Since the structural condition is load dependent, the PERFORM ANALYSIS
command is specified once for each primary load case.
This problem is installed with the program by default to C:\Users\Public\Public Documents\STAAD.Pro 2024\Samples \Sample Models\US\US-25 Analysis of a Structure with Compression-Only Members.STD when you install the program.
UNIT FEET KIP
Units for the commands to follow are specified above.
JOINT COORDINATES
1 0 0 ; 2 0 10 ; 3 0 20 ; 4 15 20 ; 5 15 10 ; 6 15 0
MEMBER PROPERTY AMERICAN
1 TO 10 TA ST W12X26
Properties for members 1 to 10 are defined as the STandard W12X26 section from the American AISC steel table.
MEMBER PROPERTY BRITISH
1 TO 10 TA ST UC152X152X30
DEFINE MATERIAL START
ISOTROPIC STEEL
E 29000
POISSON 0.3
DENSITY 283e-006
ALPHA 6e-006
DAMP 0.03
TYPE STEEL
STRENGTH FY 36 FU 58 RY 1.5 RT 1.2
END DEFINE MATERIAL
CONSTANT
MATERIAL STEEL ALL
The DEFINE MATERIAL
command is used to specify material properties and the CONSTANT
is used to assign the material to all members.
SUPPORT
1 6 PINNED
Joints 1 and 6 are declared as pinned-supported.
LOAD 1
JOINT LOAD
2 FX 15
3 FX 10
LOAD 2
JOINT LOAD
4 FX -10
5 FX -15
LOAD 3
JOINT LOAD
2 FX 15
3 FX 10
4 FX -15
5 FX –10
PERFORM ANALYSIS
Input File
STAAD PLANE EXAMPLE FOR COMPRESSION-ONLY MEMBERS
UNIT FEET KIP
SET NL 3
JOINT COORDINATES
1 0 0 ; 2 0 10 ; 3 0 20 ; 4 15 20 ; 5 15 10 ; 6 15 0
MEMBER INCIDENCES
1 1 2 5
6 1 5 ; 7 2 6 ; 8 2 4 ; 9 3 5 ; 10 2 5
MEMBER COMPRESSION
6 TO 9
MEMBER PROPERTY AMERICAN
1 TO 10 TA ST W12X26
UNIT INCH
DEFINE MATERIAL START
ISOTROPIC STEEL
E 29000
POISSON 0.3
DENSITY 283e-006
ALPHA 6e-006
DAMP 0.03
TYPE STEEL
STRENGTH FY 36 FU 58 RY 1.5 RT 1.2
END DEFINE MATERIAL
CONSTANT
MATERIAL STEEL ALL
SUPPORT
1 6 PINNED
LOAD 1
JOINT LOAD
2 FX 15
3 FX 10
PERFORM ANALYSIS
CHANGE
MEMBER COMPRESSION
6 TO 9
LOAD 2
JOINT LOAD
4 FX -10
5 FX -15
PERFORM ANALYSIS
CHANGE
MEMBER COMPRESSION
6 TO 9
LOAD 3
REPEAT LOAD
1 1.0 2 1.0
PERFORM ANALYSIS
CHANGE
LOAD LIST ALL
PRINT ANALYSIS RESULTS
FINISH
PAGE NO. 1
****************************************************
* *
* STAAD.Pro 2023 *
* Version 23.00.03.** *
* Proprietary Program of *
* Bentley Systems, Inc. *
* Date= JUL 4, 2024 *
* Time= 11:27:25 *
* *
* Licensed to: Bentley Systems Inc *
****************************************************
1. STAAD PLANE EXAMPLE FOR COMPRESSION-ONLY MEMBERS
INPUT FILE: D:\Documentation\STAAD.Pro\_Automated_Py\output\2024-07-04\SPro_Output_Input_Files\Sample .. .STD
2. UNIT FEET KIP
3. SET NL 3
4. JOINT COORDINATES
5. 1 0 0 ; 2 0 10 ; 3 0 20 ; 4 15 20 ; 5 15 10 ; 6 15 0
6. MEMBER INCIDENCES
7. 1 1 2 5
8. 6 1 5 ; 7 2 6 ; 8 2 4 ; 9 3 5 ; 10 2 5
9. MEMBER COMPRESSION
10. 6 TO 9
11. MEMBER PROPERTY AMERICAN
12. 1 TO 10 TA ST W12X26
13. UNIT INCH
14. DEFINE MATERIAL START
15. ISOTROPIC STEEL
16. E 29000
17. POISSON 0.3
18. DENSITY 283E-006
19. ALPHA 6E-006
20. DAMP 0.03
21. TYPE STEEL
22. STRENGTH FY 36 FU 58 RY 1.5 RT 1.2
23. END DEFINE MATERIAL
24. CONSTANT
25. MATERIAL STEEL ALL
26. SUPPORT
27. 1 6 PINNED
28. LOAD 1
29. JOINT LOAD
30. 2 FX 15
31. 3 FX 10
32. PERFORM ANALYSIS
EXAMPLE FOR COMPRESSION-ONLY MEMBERS -- PAGE NO. 2
P R O B L E M S T A T I S T I C S
-----------------------------------
NUMBER OF JOINTS 6 NUMBER OF MEMBERS 10
NUMBER OF PLATES 0 NUMBER OF SOLIDS 0
NUMBER OF SURFACES 0 NUMBER OF SUPPORTS 2
Using 64-bit analysis engine.
SOLVER USED IS THE IN-CORE ADVANCED MATH SOLVER
TOTAL PRIMARY LOAD CASES = 1, TOTAL DEGREES OF FREEDOM = 14
TOTAL LOAD COMBINATION CASES = 0 SO FAR.
*** LOAD CASE 1 -- START ITERATION NO. 2
**NOTE-Tension/Compression converged after 2 iterations, Case= 1
33. CHANGE
34. MEMBER COMPRESSION
35. 6 TO 9
36. LOAD 2
37. JOINT LOAD
38. 4 FX -10
39. 5 FX -15
40. PERFORM ANALYSIS
*** LOAD CASE 2 -- START ITERATION NO. 2
**NOTE-Tension/Compression converged after 2 iterations, Case= 2
41. CHANGE
42. MEMBER COMPRESSION
43. 6 TO 9
44. LOAD 3
45. REPEAT LOAD
46. 1 1.0 2 1.0
47. PERFORM ANALYSIS
**NOTE-Tension/Compression converged after 1 iterations, Case= 3
48. CHANGE
EXAMPLE FOR COMPRESSION-ONLY MEMBERS -- PAGE NO. 3
49. LOAD LIST ALL
50. PRINT ANALYSIS RESULTS
ANALYSIS RESULTS
EXAMPLE FOR COMPRESSION-ONLY MEMBERS -- PAGE NO. 4
JOINT DISPLACEMENT (INCH RADIANS) STRUCTURE TYPE = PLANE
------------------
JOINT LOAD X-TRANS Y-TRANS Z-TRANS X-ROTAN Y-ROTAN Z-ROTAN
1 1 0.00000 0.00000 0.00000 0.00000 0.00000 -0.00041
2 0.00000 0.00000 0.00000 0.00000 0.00000 0.00050
3 0.00000 0.00000 0.00000 0.00000 0.00000 -0.00004
2 1 0.04314 0.01262 0.00000 0.00000 0.00000 -0.00025
2 -0.05088 -0.00373 0.00000 0.00000 0.00000 0.00024
3 0.00364 0.00080 0.00000 0.00000 0.00000 -0.00001
3 1 0.07775 0.01618 0.00000 0.00000 0.00000 -0.00022
2 -0.07766 -0.00381 0.00000 0.00000 0.00000 0.00015
3 0.00255 0.00215 0.00000 0.00000 0.00000 0.00001
4 1 0.07766 -0.00381 0.00000 0.00000 0.00000 -0.00015
2 -0.07775 0.01618 0.00000 0.00000 0.00000 0.00022
3 -0.00255 0.00215 0.00000 0.00000 0.00000 -0.00001
5 1 0.05088 -0.00373 0.00000 0.00000 0.00000 -0.00024
2 -0.04314 0.01262 0.00000 0.00000 0.00000 0.00025
3 -0.00364 0.00080 0.00000 0.00000 0.00000 0.00001
6 1 0.00000 0.00000 0.00000 0.00000 0.00000 -0.00050
2 0.00000 0.00000 0.00000 0.00000 0.00000 0.00041
3 0.00000 0.00000 0.00000 0.00000 0.00000 0.00004
EXAMPLE FOR COMPRESSION-ONLY MEMBERS -- PAGE NO. 5
SUPPORT REACTIONS -UNIT KIP INCH STRUCTURE TYPE = PLANE
-----------------
JOINT LOAD FORCE-X FORCE-Y FORCE-Z MOM-X MOM-Y MOM Z
1 1 -0.13 -23.33 0.00 0.00 0.00 0.00
2 24.87 23.33 0.00 0.00 0.00 0.00
3 2.18 0.00 0.00 0.00 0.00 0.00
6 1 -24.87 23.33 0.00 0.00 0.00 0.00
2 0.13 -23.33 0.00 0.00 0.00 0.00
3 -2.18 0.00 0.00 0.00 0.00 0.00
EXAMPLE FOR COMPRESSION-ONLY MEMBERS -- PAGE NO. 6
MEMBER END FORCES STRUCTURE TYPE = PLANE
-----------------
ALL UNITS ARE -- KIP INCH (LOCAL )
MEMBER LOAD JT AXIAL SHEAR-Y SHEAR-Z TORSION MOM-Y MOM-Z
1 1 1 -23.33 0.13 0.00 0.00 0.00 0.00
2 23.33 -0.13 0.00 0.00 0.00 15.87
2 1 6.90 -0.22 0.00 0.00 0.00 -0.00
2 -6.90 0.22 0.00 0.00 0.00 -25.90
3 1 -1.47 0.03 0.00 0.00 0.00 0.00
2 1.47 -0.03 0.00 0.00 0.00 3.24
2 1 2 -6.58 0.24 0.00 0.00 0.00 12.72
3 6.58 -0.24 0.00 0.00 0.00 15.70
2 2 0.15 -0.11 0.00 0.00 0.00 -2.32
3 -0.15 0.11 0.00 0.00 0.00 -11.30
3 2 -2.50 -0.03 0.00 0.00 0.00 -2.74
3 2.50 0.03 0.00 0.00 0.00 -0.79
3 1 3 0.11 -0.15 0.00 0.00 0.00 -15.70
4 -0.11 0.15 0.00 0.00 0.00 -11.30
2 3 0.11 0.15 0.00 0.00 0.00 11.30
4 -0.11 -0.15 0.00 0.00 0.00 15.70
3 3 6.28 0.00 0.00 0.00 0.00 0.79
4 -6.28 -0.00 0.00 0.00 0.00 -0.79
4 1 4 0.15 0.11 0.00 0.00 0.00 11.30
5 -0.15 -0.11 0.00 0.00 0.00 2.32
2 4 -6.58 -0.24 0.00 0.00 0.00 -15.70
5 6.58 0.24 0.00 0.00 0.00 -12.72
3 4 -2.50 0.03 0.00 0.00 0.00 0.79
5 2.50 -0.03 0.00 0.00 0.00 2.74
5 1 5 6.90 0.22 0.00 0.00 0.00 25.90
6 -6.90 -0.22 0.00 0.00 0.00 0.00
2 5 -23.33 -0.13 0.00 0.00 0.00 -15.87
6 23.33 0.13 0.00 0.00 0.00 0.00
3 5 -1.47 -0.03 0.00 0.00 0.00 -3.24
6 1.47 0.03 0.00 0.00 0.00 0.00
6 1 1 0.00 0.00 0.00 0.00 0.00 0.00
5 0.00 0.00 0.00 0.00 0.00 0.00
2 1 29.63 0.00 0.00 0.00 0.00 0.00
5 -29.63 0.00 0.00 0.00 0.00 0.00
3 1 2.66 0.00 0.00 0.00 0.00 0.00
5 -2.66 0.00 0.00 0.00 0.00 0.00
7 1 2 29.63 0.00 0.00 0.00 0.00 0.00
6 -29.63 0.00 0.00 0.00 0.00 0.00
EXAMPLE FOR COMPRESSION-ONLY MEMBERS -- PAGE NO. 7
MEMBER END FORCES STRUCTURE TYPE = PLANE
-----------------
ALL UNITS ARE -- KIP INCH (LOCAL )
MEMBER LOAD JT AXIAL SHEAR-Y SHEAR-Z TORSION MOM-Y MOM-Z
2 2 0.00 0.00 0.00 0.00 0.00 0.00
6 0.00 0.00 0.00 0.00 0.00 0.00
3 2 2.66 0.00 0.00 0.00 0.00 0.00
6 -2.66 0.00 0.00 0.00 0.00 0.00
8 1 2 0.00 0.00 0.00 0.00 0.00 0.00
4 0.00 0.00 0.00 0.00 0.00 0.00
2 2 11.60 0.00 0.00 0.00 0.00 0.00
4 -11.60 0.00 0.00 0.00 0.00 0.00
3 2 4.51 0.00 0.00 0.00 0.00 0.00
4 -4.51 0.00 0.00 0.00 0.00 0.00
9 1 3 11.60 0.00 0.00 0.00 0.00 0.00
5 -11.60 0.00 0.00 0.00 0.00 0.00
2 3 0.00 0.00 0.00 0.00 0.00 0.00
5 0.00 0.00 0.00 0.00 0.00 0.00
3 3 4.51 0.00 0.00 0.00 0.00 0.00
5 -4.51 0.00 0.00 0.00 0.00 0.00
10 1 2 -9.55 -0.32 0.00 0.00 0.00 -28.60
5 9.55 0.32 0.00 0.00 0.00 -28.21
2 2 -9.55 0.32 0.00 0.00 0.00 28.21
5 9.55 -0.32 0.00 0.00 0.00 28.60
3 2 8.98 -0.00 0.00 0.00 0.00 -0.50
5 -8.98 0.00 0.00 0.00 0.00 0.50
************** END OF LATEST ANALYSIS RESULT **************
51. FINISH
EXAMPLE FOR COMPRESSION-ONLY MEMBERS -- PAGE NO. 8
*********** END OF THE STAAD.Pro RUN ***********
**** DATE= JUL 4,2024 TIME= 11:27:27 ****
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