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 2023\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
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
FINISHSTAAD Output File
PAGE NO. 1 **************************************************** * * * STAAD.Pro 2023 * * Version 23.00.02.*** * * Proprietary Program of * * Bentley Systems, Inc. * * Date= DEC 15, 2023 * * Time= 16: 0:38 * * * * Licensed to: Bentley Systems Inc * **************************************************** 1. STAAD PLANE EXAMPLE FOR COMPRESSION-ONLY MEMBERS INPUT FILE: D:\Documentation\STAAD.Pro\_Automated_Py\output\2023-12-15\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= DEC 15,2023 TIME= 16: 0:38 **** ************************************************************ * For technical assistance on STAAD.Pro, please visit * * http://www.bentley.com/en/support/ * * * * Details about additional assistance from * * Bentley and Partners can be found at program menu * * Help->Technical Support * * * * Copyright (c) Bentley Systems, Inc. * * http://www.bentley.com * ************************************************************