EX. US-9 Modeling Slabs and Shear Walls Using Finite Elements
The space frame structure in this example consists of frame members and finite elements (plates). The finite element part is used to model floor slabs and a shear wall. Concrete design of an element is performed.
This problem is installed with the program by default to C:\Users\Public\Public Documents\STAAD.Pro CONNECT Edition\Samples\Sample Models\US\US-9 Modeling Slabs and Shear Walls Using Finite Elements.STD when you install the program.
Actual input is shown in bold lettering followed by explanation.
STAAD SPACE
* EXAMPLE PROBLEM WITH FRAME MEMBERS AND FINITE ELEMENTS
Every STAAD input file has to begin with the word STAAD. The word SPACE signifies that the structure is a space frame and the geometry is defined through X, Y and Z axes. The second line forms the title to identify this project.
UNIT FEET KIP
The units for the data that follows are specified above.
JOINT COORD
1 0 0 0 ; 2 0 0 20
REP ALL 2 20 0 0
7 0 15 0 11 0 15 20
12 5 15 0 14 15 15 0
15 5 15 20 17 15 15 20
18 20 15 0 22 20 15 20
23 25 15 0 25 35 15 0
26 25 15 20 28 35 15 20
29 40 15 0 33 40 15 20
34 20 3.75 0 36 20 11.25 0
37 20 3.75 20 39 20 11.25 20
The joint numbers and their coordinates are defined through the above set of commands. The automatic generation facility has been used several times in the above lines. See TR.11 Joint Coordinates Specification where the joint coordinate generation facilities are described.
MEMBER INCI
*COLUMNS
1 1 7 ; 2 2 11
3 3 34 ; 4 34 35 ; 5 35 36 ; 6 36 18
7 4 37 ; 8 37 38 ; 9 38 39 ; 10 39 22
11 5 29 ; 12 6 33
*BEAMS IN Z DIRECTION AT X=0
13 7 8 16
*BEAMS IN Z DIRECTION AT X=20
17 18 19 20
*BEAMS IN Z DIRECTION AT X=40
21 29 30 24
*BEAMS IN X DIRECTION AT Z = 0
25 7 12 ; 26 12 13 ; 27 13 14 ; 28 14 18
29 18 23 ; 30 23 24 ; 31 24 25 ; 32 25 29
*BEAMS IN X DIRECTION AT Z = 20
33 11 15 ; 34 15 16 ; 35 16 17 ; 36 17 22
37 22 26 ; 38 26 27 ; 39 27 28 ; 40 28 33
The member incidences are defined through the above set of commands. For some members, the member number followed by the start and end joint numbers are defined. In other cases, STAAD's automatic generation facilities are utilized. Refer to TR.12 Member Incidences Specification for additional details.
DEFINE MESH
A JOINT 7
B JOINT 11
C JOINT 22
D JOINT 18
E JOINT 33
F JOINT 29
G JOINT 3
H JOINT 4
The above lines define the nodes of super-elements. Super-elements are plate/shell surfaces from which a number of individual plate/shell elements can be generated. In this case, the points describe the outer corners of a slab and that of a shear wall. Our goal is to define the slab and the wall as several plate/shell elements.
GENERATE ELEMENT
MESH ABCD 4 4
MESH DCEF 4 4
MESH DCHG 4 4
The above lines form the instructions to generate individual 4-noded elements from the super-element profiles. For example, the command MESH ABCD 4 4 means that STAAD.Pro has to generate 16 elements from the surface formed by the points A, B, C and D with 4 elements along the edges AB & CD and 4 elements along the edges BC & DA.
MEMB PROP
1 TO 40 PRIS YD 1 ZD 1
Members 1 to 40 are defined as a rectangular prismatic section with 1 ft depth and 1 ft width.
ELEM PROP
41 TO 88 TH 0.5
Elements 41 to 88 are defined to be 0.5 ft thick.
UNIT INCH
DEFINE MATERIAL START
ISOTROPIC CONCRETE
E 3000
POISSON 0.17
DENSITY 8.7e-005
ALPHA 5e-006
DAMP 0.05
G 1346.15
TYPE CONCRETE
STRENGTH FCU 4
END DEFINE MATERIAL
CONSTANTS
MATERIAL CONCRETE 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 TO 6 FIXED
Joints 1 to 6 are defined as fixed supported.
UNIT FEET
LOAD 1 DEAD LOAD FROM FLOOR
ELEMENT LOAD
41 TO 72 PRESSURE -1.0
Load 1 consists of a pressure load of 1 Kip/sq.ft. intensity on elements 41 to 72. The negative sign (and the default value for the axis) indicates that the load acts opposite to the positive direction of the element local z-axis.
LOAD 2 WIND LOAD
JOINT LOAD
11 33 FZ -20.
22 FZ -100.
Load 2 consists of joint loads in the Z direction at joints 11, 22, and 33.
LOAD COMB 3
1 0.9 2 1.3
Load 3 is a combination of 0.9 times load case 1 and 1.3 times load case 2.
PERFORM ANALYSIS
The command to perform an elastic analysis is specified above.
LOAD LIST 1 3
PRINT SUPP REAC
PRINT MEMBER FORCES LIST 27
PRINT ELEMENT STRESSES LIST 47
Support reactions, members forces and element stresses are printed for load cases 1 and 3.
START CONCRETE DESIGN
CODE ACI
DESIGN ELEMENT 47
END CONCRETE DESIGN
The above set of command form the instructions to STAAD to perform a concrete design on element 47. Design is done according to the ACI 318 code. Note that design will consist only of flexural reinforcement calculations in the longitudinal and transverse directions of the elements for the moments MX and MY.
FINI
The STAAD run is terminated.
Input File
STAAD SPACE
* EXAMPLE PROBLEM WITH FRAME MEMBERS AND
* FINITE ELEMENTS
UNIT FEET KIP
JOINT COORD
1 0 0 0 ; 2 0 0 20
REP ALL 2 20 0 0
7 0 15 0 11 0 15 20
12 5 15 0 14 15 15 0
15 5 15 20 17 15 15 20
18 20 15 0 22 20 15 20
23 25 15 0 25 35 15 0
26 25 15 20 28 35 15 20
29 40 15 0 33 40 15 20
34 20 3.75 0 36 20 11.25 0
37 20 3.75 20 39 20 11.25 20
MEMBER INCI
*COLUMNS
1 1 7 ; 2 2 11
3 3 34 ; 4 34 35 ; 5 35 36 ; 6 36 18
7 4 37 ; 8 37 38 ; 9 38 39 ; 10 39 22
11 5 29 ; 12 6 33
*BEAMS IN Z DIRECTION AT X=0
13 7 8 16
*BEAMS IN Z DIRECTION AT X=20
17 18 19 20
*BEAMS IN Z DIRECTION AT X=40
21 29 30 24
*BEAMS IN X DIRECTION AT Z = 0
25 7 12 ; 26 12 13 ; 27 13 14 ; 28 14 18
29 18 23 ; 30 23 24 ; 31 24 25 ; 32 25 29
*BEAMS IN X DIRECTION AT Z = 20
33 11 15 ; 34 15 16 ; 35 16 17 ; 36 17 22
37 22 26 ; 38 26 27 ; 39 27 28 ; 40 28 33
DEFINE MESH
A JOINT 7
B JOINT 11
C JOINT 22
D JOINT 18
E JOINT 33
F JOINT 29
G JOINT 3
H JOINT 4
GENERATE ELEMENT
MESH ABCD 4 4
MESH DCEF 4 4
MESH DCHG 4 4
MEMB PROP
1 TO 40 PRIS YD 1 ZD 1
ELEM PROP
41 TO 88 TH 0.5
UNIT INCH
DEFINE MATERIAL START
ISOTROPIC CONCRETE
E 3000
POISSON 0.17
DENSITY 8.7e-005
ALPHA 5e-006
DAMP 0.05
G 1346.15
TYPE CONCRETE
STRENGTH FCU 4
END DEFINE MATERIAL
CONSTANTS
MATERIAL CONCRETE ALL
SUPPORT
1 TO 6 FIXED
UNIT FEET
LOAD 1 DEAD LOAD FROM FLOOR
ELEMENT LOAD
41 TO 72 PRESSURE -1.0
LOAD 2 WIND LOAD
JOINT LOAD
11 33 FZ -20.
22 FZ -100.
LOAD COMB 3
1 0.9 2 1.3
PERFORM ANALYSIS
LOAD LIST 1 3
PRINT SUPP REAC
PRINT MEMBER FORCES LIST 27
PRINT ELEMENT STRESSES LIST 47
START CONCRETE DESIGN
CODE ACI
DESIGN ELEMENT 47
END CONCRETE DESIGN
FINI
STAAD Output File
PAGE NO. 1 **************************************************** * * * STAAD.Pro CONNECT Edition * * Version 22.12.00.*** * * Proprietary Program of * * Bentley Systems, Inc. * * Date= OCT 27, 2022 * * Time= 15:10:33 * * * * Licensed to: Bentley Systems Inc * **************************************************** 1. STAAD SPACE INPUT FILE: US-9 Modeling Slabs and Shear Walls Using Finite Elements.STD 2. * EXAMPLE PROBLEM WITH FRAME MEMBERS AND 3. * FINITE ELEMENTS 4. UNIT FEET KIP 5. JOINT COORD 6. 1 0 0 0 ; 2 0 0 20 7. REP ALL 2 20 0 0 8. 7 0 15 0 11 0 15 20 9. 12 5 15 0 14 15 15 0 10. 15 5 15 20 17 15 15 20 11. 18 20 15 0 22 20 15 20 12. 23 25 15 0 25 35 15 0 13. 26 25 15 20 28 35 15 20 14. 29 40 15 0 33 40 15 20 15. 34 20 3.75 0 36 20 11.25 0 16. 37 20 3.75 20 39 20 11.25 20 17. MEMBER INCI 18. *COLUMNS 19. 1 1 7 ; 2 2 11 20. 3 3 34 ; 4 34 35 ; 5 35 36 ; 6 36 18 21. 7 4 37 ; 8 37 38 ; 9 38 39 ; 10 39 22 22. 11 5 29 ; 12 6 33 23. *BEAMS IN Z DIRECTION AT X=0 24. 13 7 8 16 25. *BEAMS IN Z DIRECTION AT X=20 26. 17 18 19 20 27. *BEAMS IN Z DIRECTION AT X=40 28. 21 29 30 24 29. *BEAMS IN X DIRECTION AT Z = 0 30. 25 7 12 ; 26 12 13 ; 27 13 14 ; 28 14 18 31. 29 18 23 ; 30 23 24 ; 31 24 25 ; 32 25 29 32. *BEAMS IN X DIRECTION AT Z = 20 33. 33 11 15 ; 34 15 16 ; 35 16 17 ; 36 17 22 34. 37 22 26 ; 38 26 27 ; 39 27 28 ; 40 28 33 35. DEFINE MESH 36. A JOINT 7 37. B JOINT 11 38. C JOINT 22 STAAD SPACE -- PAGE NO. 2 * EXAMPLE PROBLEM WITH FRAME MEMBERS AND 39. D JOINT 18 40. E JOINT 33 41. F JOINT 29 42. G JOINT 3 43. H JOINT 4 44. GENERATE ELEMENT 45. MESH ABCD 4 4 46. MESH DCEF 4 4 47. MESH DCHG 4 4 48. MEMB PROP 49. 1 TO 40 PRIS YD 1 ZD 1 50. ELEM PROP 51. 41 TO 88 TH 0.5 52. UNIT INCH 53. DEFINE MATERIAL START 54. ISOTROPIC CONCRETE 55. E 3000 56. POISSON 0.17 57. DENSITY 8.7E-005 58. ALPHA 5E-006 59. DAMP 0.05 60. G 1346.15 61. TYPE CONCRETE 62. STRENGTH FCU 4 63. END DEFINE MATERIAL 64. CONSTANTS 65. MATERIAL CONCRETE ALL 66. SUPPORT 67. 1 TO 6 FIXED 68. UNIT FEET 69. LOAD 1 DEAD LOAD FROM FLOOR 70. ELEMENT LOAD 71. 41 TO 72 PRESSURE -1.0 72. LOAD 2 WIND LOAD 73. JOINT LOAD 74. 11 33 FZ -20. 75. 22 FZ -100. 76. LOAD COMB 3 77. 1 0.9 2 1.3 78. PERFORM ANALYSIS P R O B L E M S T A T I S T I C S ----------------------------------- NUMBER OF JOINTS 69 NUMBER OF MEMBERS 40 NUMBER OF PLATES 48 NUMBER OF SOLIDS 0 NUMBER OF SURFACES 0 NUMBER OF SUPPORTS 6 Using 64-bit analysis engine. STAAD SPACE -- PAGE NO. 3 * EXAMPLE PROBLEM WITH FRAME MEMBERS AND SOLVER USED IS THE IN-CORE ADVANCED MATH SOLVER TOTAL PRIMARY LOAD CASES = 2, TOTAL DEGREES OF FREEDOM = 378 TOTAL LOAD COMBINATION CASES = 1 SO FAR. 79. LOAD LIST 1 3 80. PRINT SUPP REAC SUPP REAC STAAD SPACE -- PAGE NO. 4 * EXAMPLE PROBLEM WITH FRAME MEMBERS AND SUPPORT REACTIONS -UNIT KIP FEET STRUCTURE TYPE = SPACE ----------------- JOINT LOAD FORCE-X FORCE-Y FORCE-Z MOM-X MOM-Y MOM Z 1 1 9.11 82.56 11.46 56.95 -0.01 -45.28 3 8.23 74.62 10.65 54.04 0.03 -40.81 2 1 9.11 82.56 -11.46 -56.95 0.01 -45.28 3 8.19 73.98 -9.97 -48.33 0.19 -40.77 3 1 0.00 234.89 75.78 -39.25 0.00 0.00 3 0.00 345.09 160.48 -19.17 0.00 0.00 4 1 0.00 234.89 -75.78 39.25 0.00 0.00 3 0.00 77.69 20.17 50.98 0.00 0.00 5 1 -9.11 82.56 11.46 56.95 0.01 45.28 3 -8.23 74.62 10.65 54.04 -0.03 40.81 6 1 -9.11 82.56 -11.46 -56.95 -0.01 45.28 3 -8.19 73.98 -9.97 -48.33 -0.19 40.77 ************** END OF LATEST ANALYSIS RESULT ************** 81. PRINT MEMBER FORCES LIST 27 MEMBER FORCES LIST 27 STAAD SPACE -- PAGE NO. 5 * EXAMPLE PROBLEM WITH FRAME MEMBERS AND MEMBER END FORCES STRUCTURE TYPE = SPACE ----------------- ALL UNITS ARE -- KIP FEET (LOCAL ) MEMBER LOAD JT AXIAL SHEAR-Y SHEAR-Z TORSION MOM-Y MOM-Z 27 1 13 0.73 -13.21 -0.07 25.88 0.18 -80.00 14 -0.73 13.21 0.07 -25.88 0.18 13.96 3 13 5.42 -11.85 -0.21 23.44 0.51 -72.04 14 -5.42 11.85 0.21 -23.44 0.53 12.79 ************** END OF LATEST ANALYSIS RESULT ************** 82. PRINT ELEMENT STRESSES LIST 47 ELEMENT STRESSES LIST 47 STAAD SPACE -- PAGE NO. 6 * EXAMPLE PROBLEM WITH FRAME MEMBERS AND ELEMENT STRESSES FORCE,LENGTH UNITS= KIP FEET ---------------- STRESS = FORCE/UNIT WIDTH/THICK, MOMENT = FORCE-LENGTH/UNIT WIDTH ELEMENT LOAD SQX SQY MX MY MXY VONT VONB SX SY SXY TRESCAT TRESCAB 47 1 1.71 0.50 -11.52 -14.78 1.47 330.22 326.90 -1.21 -1.70 0.52 370.35 366.37 TOP : SMAX= -263.74 SMIN= -370.35 TMAX= 53.30 ANGLE= 21.2 BOTT: SMAX= 366.37 SMIN= 261.89 TMAX= 52.24 ANGLE=-69.1 3 1.53 0.45 -10.40 -13.30 1.29 299.11 292.24 -1.83 -2.46 4.00 336.09 326.02 TOP : SMAX= -236.95 SMIN= -336.09 TMAX= 49.57 ANGLE= 22.4 BOTT: SMAX= 326.02 SMIN= 238.44 TMAX= 43.79 ANGLE=-71.0 **** MAXIMUM STRESSES AMONG SELECTED PLATES AND CASES **** MAXIMUM MINIMUM MAXIMUM MAXIMUM MAXIMUM PRINCIPAL PRINCIPAL SHEAR VONMISES TRESCA STRESS STRESS STRESS STRESS STRESS 3.663715E+02 -3.703516E+02 5.330365E+01 3.302169E+02 3.703516E+02 PLATE NO. 47 47 47 47 47 CASE NO. 1 1 1 1 1 ********************END OF ELEMENT FORCES******************** 83. START CONCRETE DESIGN STAAD SPACE -- PAGE NO. 7 * EXAMPLE PROBLEM WITH FRAME MEMBERS AND CONCRETE DESIGN 84. CODE ACI 85. DESIGN ELEMENT 47 STAAD SPACE -- PAGE NO. 8 * EXAMPLE PROBLEM WITH FRAME MEMBERS AND **WARNING** - ELEMENT DESIGN to ACI 318-14 is not available in this version of STAAD.Pro 86. END CONCRETE DESIGN 87. FINI *********** END OF THE STAAD.Pro RUN *********** **** DATE= OCT 27,2022 TIME= 15:10:33 **** ************************************************************ * 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 * ************************************************************