Hi, I have some questions regarding member check to AISC 360-10.
So I was doing some check on a simple member (attached output file), and then I checked it using hand calculation to verify the numbers (I need to know how the program do simpler problem before doing harder analysis not solvable by hand) and found some problem.
1. I came into the conclusion that the check for minor axis shear (Z-axis) uses shear area Aw of 4/3 bf*tf (width and thickness of flange) while the code suggests bf*tf (section G7). Is this intentional? And if it is, please sugggest the reasoning behind the 4/3 factor.
2. While doing the check for torsion, I also came to the conclusion that the formula that is used to calculate pure flexure shear stress at flange-web junction to be a bit weird, as I think the shear stress should be obtained by dividing the contribution by strong axis shear by the thickness of the web, and weak axis shear by the thickness of the flange, not otherwise (see below picture). Again please suggest the reasoning behind this, or if I used the wrong formula.
Thank you.
PAGE NO. 1 **************************************************** * * * STAAD.Pro V8i SELECTseries5 * * Version 20.07.10.65 * * Proprietary Program of * * Bentley Systems, Inc. * * Date= APR 15, 2015 * * Time= 9:51:36 * * * * USER ID: EMAS * **************************************************** 1. STAAD SPACE INPUT FILE: S2.STD 2. START JOB INFORMATION 3. ENGINEER DATE 10-APR-15 4. END JOB INFORMATION 5. INPUT WIDTH 79 6. UNIT METER KN 7. JOINT COORDINATES 8. 1 0 0 0; 2 0 14.9998 0 9. MEMBER INCIDENCES 10. 1 1 2 11. DEFINE MATERIAL START 12. ISOTROPIC STEEL 13. E 2.05E+008 14. POISSON 0.3 15. DENSITY 76.8195 16. ALPHA 1.2E-005 17. DAMP 0.03 18. TYPE STEEL 19. STRENGTH FY 253200 FU 407800 RY 1.5 RT 1.2 20. END DEFINE MATERIAL 21. MEMBER PROPERTY AMERICAN 22. 1 TABLE ST W24X192 23. CONSTANTS 24. MATERIAL STEEL ALL 25. SUPPORTS 26. 1 2 FIXED 27. LOAD 1 LOADTYPE NONE TITLE LOAD CASE 1 **WARNING** - ALL DEGREES OF FREEDOM FIXED. STAAD WILL INFINITESIMALLY RELEASE MOMENT-X AT FIRST JOINT ENTERED. 28. MEMBER LOAD 29. 1 CON GY 300 5 0 30. 1 CON GX -75 5 0 31. 1 CON GZ 25 5 0 32. 1 CMOM GY 35 5 0 33. PERFORM ANALYSIS PRINT ALL STAAD SPACE -- PAGE NO. 2 P R O B L E M S T A T I S T I C S ----------------------------------- NUMBER OF JOINTS 2 NUMBER OF MEMBERS 1 NUMBER OF PLATES 0 NUMBER OF SOLIDS 0 NUMBER OF SURFACES 0 NUMBER OF SUPPORTS 2 SOLVER USED IS THE OUT-OF-CORE BASIC SOLVER ORIGINAL/FINAL BAND-WIDTH= 1/ 1/ 1 DOF TOTAL PRIMARY LOAD CASES = 1, TOTAL DEGREES OF FREEDOM = 1 TOTAL LOAD COMBINATION CASES = 0 SO FAR. SIZE OF STIFFNESS MATRIX = 0 DOUBLE KILO-WORDS REQRD/AVAIL. DISK SPACE = 12.0/ 675.0 MB STAAD SPACE -- PAGE NO. 3 LOADING 1 LOADTYPE NONE TITLE LOAD CASE 1 ----------- MEMBER LOAD - UNIT KN METE MEMBER UDL L1 L2 CON L LIN1 LIN2 1 300.0000 GY 5.00 1 -75.0000 GX 5.00 1 25.0000 GZ 5.00 1 35.000 GY 5.00 CONCENTRATED MOMENT FOR LOADING - 1 APPLIED JOINT EQUIVALENT LOADS JOINT FORCE-X FORCE-Y FORCE-Z MOM-X MOM-Y MOM-Z 1-5.55551E+01 1.99999E+02 1.85184E+01 5.55548E+01 2.33332E+01 1.66664E+02 2-1.94449E+01 1.00001E+02 6.48163E+00-2.77780E+01 1.16668E+01-8.33339E+01 STATIC LOAD/REACTION/EQUILIBRIUM SUMMARY FOR CASE NO. 1 LOADTYPE NONE TITLE LOAD CASE 1 CENTER OF FORCE BASED ON X FORCES ONLY (METE). (FORCES IN NON-GLOBAL DIRECTIONS WILL INVALIDATE RESULTS) X = 0.000000000E+00 Y = 0.500000001E+01 Z = -0.466666709E+00 CENTER OF FORCE BASED ON Y FORCES ONLY (METE). (FORCES IN NON-GLOBAL DIRECTIONS WILL INVALIDATE RESULTS) X = 0.277768515E+00 Y = 0.500000025E+01 Z = -0.925895147E-01 CENTER OF FORCE BASED ON Z FORCES ONLY (METE). (FORCES IN NON-GLOBAL DIRECTIONS WILL INVALIDATE RESULTS) X = -0.140000015E+01 Y = 0.500000040E+01 Z = 0.000000000E+00 TOTAL APPLIED LOAD 1 ***TOTAL APPLIED LOAD ( KN METE ) SUMMARY (LOADING 1 ) SUMMATION FORCE-X = -75.00 SUMMATION FORCE-Y = 300.00 SUMMATION FORCE-Z = 25.00 SUMMATION OF MOMENTS AROUND THE ORIGIN- MX= 125.00 MY= 35.00 MZ= 375.00 STAAD SPACE -- PAGE NO. 4 TOTAL REACTION LOAD 1 ***TOTAL REACTION LOAD( KN METE ) SUMMARY (LOADING 1 ) SUMMATION FORCE-X = 75.00 SUMMATION FORCE-Y = -300.00 SUMMATION FORCE-Z = -25.00 SUMMATION OF MOMENTS AROUND THE ORIGIN- MX= -125.00 MY= -35.00 MZ= -375.00 MAXIMUM DISPLACEMENTS ( CM /RADIANS) (LOADING 1) MAXIMUMS AT NODE X = 0.00000E+00 0 Y = 0.00000E+00 0 Z = 0.00000E+00 0 RX= 4.91696E-08 1 RY= 0.00000E+00 0 RZ= 0.00000E+00 0 EXTERNAL AND INTERNAL JOINT LOAD SUMMARY ( KN METE )- JT EXT FX/ EXT FY/ EXT FZ/ EXT MX/ EXT MY/ EXT MZ/ INT FX INT FY INT FZ INT MX INT MY INT MZ SUPPORT=1 1 -55.56 200.00 18.52 55.55 23.33 166.66 0.00 0.00 0.00 0.00 0.00 0.00 111111 2 -19.44 100.00 6.48 -27.78 11.67 -83.33 0.00 0.00 0.00 0.00 0.00 0.00 111111 ************ END OF DATA FROM INTERNAL STORAGE ************ 34. PARAMETER 1 35. CODE AISC UNIFIED 2010 36. METHOD ASD 37. BEAM 1 ALL 38. CB 1 ALL 39. FLX 1 ALL 40. FU 410000 ALL 41. FYLD 245000 ALL 42. STP 1 ALL 43. TORSION 1 ALL 44. TRACK 2 ALL 45. CHECK CODE ALL STEEL DESIGN STAAD SPACE -- PAGE NO. 5 STAAD.PRO CODE CHECKING - ( AISC-360-10-ASD) v1.3a ******************************************** ALL UNITS ARE - KIP INCH (UNLESS OTHERWISE Noted) -------------------- START OF DESIGN OUTPUT OF MEMBER 1 -------------------- *MEMBER NO: 1 CRITICAL RATIO: 1.207(FAIL) LOAD: 1 LOCATION (ft): 0.00 CONDITION: Eq. H3-7 SECTION: ST W24X192 (AISC SECTIONS) UNIT: KIP FEET STRENGTH CHECKS: CRITICAL RATIO: 1.207(FAIL) LOAD CASE: 1 LOCATION (ft): 0.00 CONDITION: Eq. H3-7 DESIGN FORCES: Fx: 44.96(T) Fy: -12.49 Fz: -4.16 Mx: -1.72E+01 My: 4.10E+01 Mz: -1.23E+02 SECTION PROPERTIES: AZZ: 25.209 AYY: 20.631 CW: 76383.609 SZZ: 491.559 SYY: 81.853 IZZ: 6260.000 IYY: 530.000 MATERIAL PROPERTIES: FYLD: 35.534 FU: 59.465 ACTUAL MEMBER LENGTH(ft): 49.210 PARAMETERS: KZ: 1.000 KY: 1.000 NSF: 1.000 SLF: 1.000 CSP: 1.000 SLENDERNESS: ACTUAL SLENDERNESS RATIO: 192.472 LOAD: 1 LOC.(ft): 0.000 ALLOWABLE SLENDERNESS RATIO: 300.000 SECTION CLASS: FLANGE:/ l: lp: lr: WEB: COMPRESSION: Non-Slender 4.435 N/A 16.199 Non-Slender 27.840 N/A 43.100 FLEXURE: Compact 4.435 10.992 28.926 Compact 27.840 108.763 164.880 TENSION: FORCE: CAPACITY: RATIO: CRITERIA: LOAD CASE: LOCATION(ft): YIELDING: 44.961 1197.951 0.038 Eq. D2-1 1 0.000 RUPTURE: 44.961 1673.953 0.027 Eq. D2-2 1 0.000 STAAD SPACE -- PAGE NO. 6 STAAD.PRO CODE CHECKING - ( AISC-360-10-ASD) v1.3a ******************************************** ALL UNITS ARE - KIP INCH (UNLESS OTHERWISE Noted) COMPRESSION: FORCE: CAPACITY: RATIO: CRITERIA: LOAD CASE: LOCATION(ft): MAJOR: 22.481 1021.885 0.022 Eq. E3-1 1 49.210 MINOR: 22.481 234.202 0.096 Eq. E3-1 1 49.210 INTERMEDIATE: Ag: KL/r: Fcr: Fe: Pn: MAJOR: 56.300 56.004 30.312 93.561 1706.548 MINOR: 56.300 192.472 6.947 7.921 391.117 FLEX TOR BUCK: FORCE: CAPACITY: RATIO: CRITERIA: LOAD CASE: LOCATION(ft): 22.481 941.262 0.024 Eq. E4-1 1 49.210 INTERMEDIATE: Ag: Fcr: Pn: 56.300 27.920 1571.908 SHEAR: FORCE: CAPACITY: RATIO: CRITERIA: LOAD CASE: LOCATION(ft): MAJOR(VZ): 4.163 321.834 0.013 Eq. G2-1 1 0.000 MINOR(VY): -12.489 293.239 0.043 Eq. G2-1 1 0.000 INTERMEDIATE: Aw: Cv: Kv: h/tw: Vn: MAJOR(VZ): 25.209 1.000 1.200 4.435 537.463 MINOR(VY): 20.631 1.000 0.000 27.840 439.858 UNIT: KIP FEET YIELDING: FORCE: CAPACITY: RATIO: CRITERIA: LOAD CASE: LOCATION(ft): MAJOR: 1.23E+02 9.91E+02 0.124 Eq. F2-1 1 0.000 MINOR: 4.10E+01 2.23E+02 0.183 Eq. F6-1 1 0.000 INTERMEDIATE: Mnr: My: Cb: MAJOR: 1.66E+03 0.00E+00 1.000 MINOR: 3.73E+02 0.00E+00 1.000 UNIT: KIP FEET LAT TOR BUCK: FORCE: CAPACITY: RATIO: CRITERIA: LOAD CASE: LOCATION(ft): MAJOR: 1.23E+02 6.57E+02 0.187 Eq. F2-2 1 0.000 INTERMEDIATE: Mn: Me: Cb: Lp: Lr: Lb: MAJOR: 1.10E+03 0.00E+00 1.000 13.016 54.296 49.210 UNIT: KIP FEET INTERACTION: RATIO: CRITERIA: LOAD CASE: LOCATION(ft): FLEXURE COMP: 0.370 Eq. H1-1b 1 0.000 FLEXURE TENS: 0.389 Eq. H1-1b 1 0.000 INTERMEDIATE: Mcx: Mcy: Mrx: Mry: Pc: Pr: FLEXURE COMP: 6.57E+02 2.23E+02 1.23E+02 4.10E+01 234.202 0.000 FLEXURE TENS: 6.57E+02 2.23E+02 1.23E+02 4.10E+01 1197.951 44.961 STAAD SPACE -- PAGE NO. 7 STAAD.PRO CODE CHECKING - ( AISC-360-10-ASD) v1.3a ******************************************** ALL UNITS ARE - KIP INCH (UNLESS OTHERWISE Noted) UNIT: KIP FEET INTERACTION: RATIO: CRITERIA: LOAD CASE: LOCATION(ft): IN PLANE FLEX: 0.044 Eq. H1-1b 1 41.008 OUT PLANE FLEX: 0.072 Eq. H1-2 1 41.008 INTERMEDIATE: Pc: Pr: Mc: Mr: IN PLANE FLEX: 1.02E+03 1.12E+01 657.052 25.609 OUT PLANE FLEX: 2.34E+02 1.12E+01 657.052 25.609 -------------------- END OF DESIGN OUTPUT OF MEMBER 1 -------------------- ****** AISC DESIGN GUIDE 9 ****** MEMBER: 1 SECTION: W24X192 AISC END CONDITION: FIX-FIX SHEAR CAPACITY: 12.77 SHEAR CRITERIA: Eq. H3-8 NORMAL CAPACITY: 21.28 NORMAL CRITERIA: Eq. H3-7 STRESS LOC SHEAR RATIO LOAD CASE/ | STRESS LOC NORMAL RATIO LOAD CASE/ SECTION | SECTION MID FLANGE 0.78 0.06 1 | FLANGE EDGE 25.67 1.21 1 0.00 | 0.00 FL-WB JUNC 6.38 0.50 1 | 0.17 | MID WEB 3.72 0.29 1 | 0.17 | PURE TORSION SHEAR STRESS CRITERIA: DG9 Eq. 4.1 FLANGE EDGE: 5.43 WEB EDGE: 3.01 WARPING SHEAR STRESS CRITERIA: DG9 Eq. 4.2a MID FLANGE: 0.73 WARPING NORMAL STRESS CRITERIA: DG9 Eq. 4.3a FLANGE EDGE: 15.87 PURE FLEXURE SHEAR STRESS CRITERIA: DG9 Eq. 4.6 MID FLANGE: 0.05 FLANGE-WEB JUNC: 0.61 MID WEB: 0.71 DIRECT AXIAL BENDING STRESS CRITERIA: DG9 Eq. 4.5 FLANGE EDGE: 9.81 46. FINISH STAAD SPACE -- PAGE NO. 8 *********** END OF THE STAAD.Pro RUN *********** **** DATE= APR 15,2015 TIME= 9:51:41 **** ************************************************************ * For technical assistance on STAAD.Pro, please visit * * http://selectservices.bentley.com/en-US/ * * * * Details about additional assistance from * * Bentley and Partners can be found at program menu * * Help->Technical Support * * * * Copyright (c) 1997-2014 Bentley Systems, Inc. * http://www.bentley.com * ************************************************************