V. ASME NF 3000 1974 Pipe
Verify the design of a pipe section used for a beam member per the ASME NF 3000 1974 code.
Details
The simply supported beam is 50 inches long. The beam is loaded with a 1.5 kip concentrated load at midspan and a uniformly distributed load of 1 kip/in over the entire length.
The member is PIPS 120 pipe section with Grade A36 steel.
Validation
Maximum shear force,
Maximum moment,
Slenderness ratio = (KL/r) = 9.72 < 300
Bending About Major Axis (Z-Axis)
Section is compact:
Allowable bending stress: Fb = 0.66×Fy = 23.76 ksi
Actual bending stress:
Stress ratio: 0.339
Shear
From the reference, the shear area:
Shear area: Ay = 6.8 in2
Actual shear stress (at supports): fv = 25.75 / 6.8 = 3.78 ksi
Actual shear stress (at midspan): fv = 0.75 / 6.8 = 0.110 ksi
Allowable shear stress, Fv = 0.4×Fy = 14.4 ksi
Stress ratio: 3.78/14.4 = 0.263
Results
Parameter | Hand Calculation | STAAD.Pro | Difference | Comments |
---|---|---|---|---|
Slenderness ratio | 9.72 | 9.72 | none | |
Allowable bending stress (ksi) | 23.8 | 23.8 | none | |
Actual bending stress (ksi) | 8.06 | 8.06 | none | |
Critical stress ratio | 0.339 | 0.339 | none | |
Allowable shear stress (ksi) | 14.4 | 14.4 | none | |
Shear stress ratio | 0.201 | 0.201 | none |
STAAD Input
The file C:\Users\Public\Public Documents\STAAD.Pro 2024\Samples \Verification Models\09 Steel Design\US\ASME\ASME NF 3000 1974 Pipe.std is typically installed with the program.
STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 17-Aug-18
END JOB INFORMATION
SET SHEAR
INPUT WIDTH 79
UNIT INCHES POUND
JOINT COORDINATES
1 0 0 0; 2 50 0 0;
MEMBER INCIDENCES
1 1 2;
DEFINE MATERIAL START
ISOTROPIC STEEL
E 2.9e+007
POISSON 0.3
DENSITY 0.283
ALPHA 1.2e-005
DAMP 0.03
TYPE STEEL
STRENGTH FY 36000 FU 58000 RY 1.5 RT 1.2
END DEFINE MATERIAL
MEMBER PROPERTY AMERICAN
1 TABLE ST PIPS120
CONSTANTS
MATERIAL STEEL ALL
SUPPORTS
1 PINNED
2 FIXED BUT FX MY MZ
LOAD 1 LOADTYPE None TITLE LOAD CASE 1
MEMBER LOAD
1 CON GY -1500 25 0
1 UNI GY -1000 0 50
PERFORM ANALYSIS
PARAMETER 1
CODE NF3000 1974
CMY 1 ALL
CMZ 1 ALL
CT 0.85 ALL
FU 58000 ALL
FYLD 36000 ALL
KY 0.85 ALL
KZ 0.85 ALL
UNT 50 ALL
UNB 50 ALL
MAIN 200 ALL
NSF 0.9 ALL
RATIO 1 ALL
TMAIN 300 ALL
UNB 25 ALL
UNT 25 ALL
TRACK 2 ALL
CHECK CODE ALL
FINISH
STAAD Output
STAAD.PRO CODE CHECKING - ( ASME NF3000-74) v2.0
********************************************
ALL UNITS ARE - POUN INCH (UNLESS OTHERWISE Noted)
MEMBER TABLE RESULT/ CRITICAL COND/ RATIO/ LOADING/
FX MY MZ LOCATION
=======================================================================
1 ST PIPS120 (AISC SECTIONS)
PASS NF-74-EQN-21 0.339 1
0.00 T 0.00 -331249.97 25.00
|-----------------------------------------------------------------------------|
| SLENDERNESS CHECK: ACTUAL RATIO: 9.72 ALLOWABLE RATIO: 300.00 |
| ALLOWABLE STRESSES: (UNIT - POUN INCH) |
| AXIAL: 2.12E+04 FCZ: 2.38E+04 FCY: 2.38E+04 FTZ: 2.38E+04 FTY: 2.38E+04 |
| SHEAR: 1.44E+04 |
| ACTUAL STRESSES: (UNIT - POUN INCH) |
| AXIAL: 0.00E+00 FBZ: 8.06E+03 FBY: 0.00E+00 SHEAR: 8.43E+01 |
|-----------------------------------------------------------------------------|
| SECTION PROPERTIES: (UNIT - INCH) |
| AXX: 13.70 AYY: 7.01 AZZ: 7.01 RZZ: 4.37 RYY: 4.37 |
| SZZ: 41.10 SYY: 41.10 |
|-----------------------------------------------------------------------------|
| PARAMETER: (UNIT - POUN INCH) |
| KL/R-Z: 9.72 KL/R-Y: 9.72 UNL: 25.0 CMZ: 1.00 CMY: 1.00 |
| CB: 1.00 FYLD: 36000.00 FU: 58000.00 NET SECTION FACTOR: 0.90 |
| KS:1.000 KV:1.000 KBK:1.000 |
|-----------------------------------------------------------------------------|
| CRITICAL LOADS FOR EACH CLAUSE CHECK (UNITS POUN-INCH) |
| CLAUSE RATIO LOAD FX VY VZ MZ MY |
| TENSION 0.000 0 0.00E+00 - - - - |
| COMPRESSION 0.000 0 0.00E+00 - - - - |
| COMP&BEND 0.339 1 0.00E+00 - - 3.31E+05 0.00E+00 |
| TEN&BEND 0.000 0 0.00E+00 - - 0.00E+00 0.00E+00 |
| SHEAR-Y 0.201 1 - 2.57E+04 - - - |
| SHEAR-Z 0.000 0 - - 0.00E+00 - - |
|-----------------------------------------------------------------------------|