V. AISC N690 1994 Pipe Section With SLC
Verify the design of a pipe section used for a beam member per the AISC N690 1994 code.
References
Gere, J. M. and S. P. Timoshenko. 1984. Mechanics of Materials, 2nd Edition. Boston, MA: PWS Publishers. p.238.
Details
- a 10 kip axial tension force,
- a 10 kip axial compression force,
- a uniformly distributed load of 0.3 kip/ft in the Global Y directions, the member selfweight (acts in Global Y), and the tension load from case 1
- a uniformly distributed load of 0.3 kip/ft in the Global Y directions, the member selfweight (acts in Global Y), and the compression load from case 2
The member is Pipe 5-Sched. 40 (standard) pipe section with Grade A36 steel. The self-weight is 14.6 lbs/ft.
Validation
Slenderness Ratio
The slenderness ratio is the same about either local z or y axes: KL/r = 120 in / 1.888 in = 63.56 < 300, OK
Axial Tension
From section Q1.5.1.1, the allowable tensile stress:
The actual tensile stress from load case 1:
Stress ratio = 2.49 / 21.6 = 0.115, hence OK.
Axial Compression
Allowable compressive stress per Cl Q1.9.2.3:
Since Kl/r < Cc, per eq. Q1.5-1, the allowable axial compressive stress:
The actual compressive stress from load case 2:
Stress ratio = 2.49 / 17.08 = 0.146, hence OK.
Bending
Section is compact per Cl Q1.5.1.4.1:
Allowable bending stress about both axes: Fb = 0.66×Fy = 23.76 ksi
Moment due to load case 3 or 4 on a propped cantilever (ref. AISC Steel Construction Manual):
Actual bending stress about the major axis:
(actual bending about the minor axis: )
Stress ratio: 9.17 / 23.76 = 0.386, hence OK.
Combined Bending and Axial Tension
Interaction per Cl Q1.6.2 in load case 3 (tension + bending):
(Eq. Q1.6-1b) |
Combined Bending and Axial Compression
Interaction per Cl Q1.6 in load case 4 (compression + bending):
(Eq. Q1.6-2) |
Shear
Actual shear (at supports):
Shear area (calculated as per Gere & Timoshenko reference):
where= | ||
= |
Thus, the shear area along both axes = 2.008 in2.
(shear stress in major axis = 0)
The allowable shear stress:
Stress ratio in Y (minor axis): 0.98/14.4 = 0.068, hence OK.
Results
Parameter | Hand Calculation | STAAD.Pro | Difference | Comments |
---|---|---|---|---|
Slenderness ratio | 63.56 | 63.55 | negligible | |
Actual axial tensile stress (ksi) | 2.49 | 2.49 | none | |
Allowable axial tensile stress (ksi) | 21.6 | 21.6 | none | |
Tensile stress ratio (LC1) | 0.115 | 0.115 | none | |
Actual axial compressive stress (ksi) | 2.49 | 2.49 | none | |
Allowable axial compressive stress (ksi) | 17.08 | 17.08 | none | |
Compressive stress ratio (LC2) | 0.146 | 0.146 | none | |
Allowable bending stress (ksi) | 23.76 | 23.8 | negligible | |
Actual bending stress (ksi) | 9.17 | 9.15 | negligible | |
Combined axial tension and bending stress ratio (LC3) | 0.364 | 0.363 | negligible | |
Combined axial compression and bending stress ratio (LC4) | 0.388 | 0.386 | negligible | |
Allowable shear stress (ksi) | 14.4 | 14.4 | none | |
Actual shear stress (ksi) | 0.98 | 0.97 | negligible | |
Shear stress ratio, Y | 0.068 | 0.067 | negligible |
STAAD Input
The file C:\Users\Public\Public Documents\STAAD.Pro 2023\Samples \Verification Models\09 Steel Design\US\AISC\AISC N690 1994 Pipe Section With SLC.std is typically installed with the program.
STAAD SPACE
START JOB INFORMATION
ENGINEER DATE 05-Apr-19
END JOB INFORMATION
INPUT WIDTH 79
SET SHEAR
UNIT FEET KIP
JOINT COORDINATES
1 0 0 0; 2 10 0 0;
MEMBER INCIDENCES
1 1 2;
DEFINE MATERIAL START
ISOTROPIC STEEL
E 4.176e+006
POISSON 0.3
DENSITY 0.489024
ALPHA 1.2e-005
DAMP 0.03
END DEFINE MATERIAL
UNIT INCHES KIP
MEMBER PROPERTY AMERICAN
1 TABLE ST PIPS50
UNIT FEET KIP
CONSTANTS
MATERIAL STEEL ALL
SUPPORTS
1 PINNED
2 FIXED BUT FX
LOAD 1 TENSION ONLY
JOINT LOAD
2 FX 10
LOAD 2 COMPRESSION ONLY
JOINT LOAD
2 FX -10
LOAD 3 TENSION+BENDING
SELFWEIGHT Y -1
MEMBER LOAD
1 UNI GY -0.3
JOINT LOAD
2 FX 10
LOAD 4 COMPRESSION+BENDING
SELFWEIGHT Y -1
MEMBER LOAD
1 UNI GY -0.3
JOINT LOAD
2 FX -10
PERFORM ANALYSIS PRINT LOAD DATA
PRINT MEMBER PROPERTIES ALL
UNIT INCHES KIP
*
LOAD LIST 1
PARAMETER 1
CODE AISC N690 1994
CB 1 ALL
CMY 1 ALL
CMZ 1 ALL
FYLD 36 ALL
FU 58 ALL
KY 1 ALL
KZ 1 ALL
MAIN 200 ALL
NSF 1 ALL
RATIO 1 ALL
TMAIN 300 ALL
TRACK 2 ALL
UNB 30 ALL
UNT 30 ALL
CT 0.75 ALL
CHECK CODE ALL
*
LOAD LIST 2
PARAMETER 2
CODE AISC N690 1994
CB 1 ALL
CMY 1 ALL
CMZ 1 ALL
FYLD 36 ALL
FU 58 ALL
KY 1 ALL
KZ 1 ALL
MAIN 200 ALL
NSF 1 ALL
RATIO 1 ALL
TMAIN 300 ALL
TRACK 2 ALL
UNB 30 ALL
UNT 30 ALL
CT 0.75 ALL
CHECK CODE ALL
*
LOAD LIST 3
PARAMETER 3
CODE AISC N690 1994
CB 1 ALL
CMY 1 ALL
CMZ 1 ALL
FYLD 36 ALL
FU 58 ALL
KY 1 ALL
KZ 1 ALL
MAIN 200 ALL
NSF 1 ALL
RATIO 1 ALL
SMZ 1.4 ALL
SMY 1.4 ALL
SFT 1.3 ALL
SFC 1.3 ALL
TMAIN 300 ALL
TRACK 2 ALL
UNB 30 ALL
UNT 30 ALL
CT 0.75 ALL
CHECK CODE ALL
*
LOAD LIST 4
PARAMETER 4
CODE AISC N690 1994
CB 1 ALL
CMY 1 ALL
CMZ 1 ALL
FYLD 36 ALL
FU 58 ALL
KY 1 ALL
KZ 1 ALL
MAIN 200 ALL
NSF 1 ALL
RATIO 1 ALL
SMZ 1.4 ALL
SMY 1.4 ALL
SFT 1.3 ALL
SFC 1.3 ALL
TMAIN 300 ALL
TRACK 2 ALL
UNB 30 ALL
UNT 30 ALL
CT 0.75 ALL
CHECK CODE ALL
*
LOAD LIST ALL
PARAMETER 5
CODE AISC N690 1994
CB 1 ALL
CMY 1 ALL
CMZ 1 ALL
FYLD 36 ALL
FU 58 ALL
KY 1 ALL
KZ 1 ALL
MAIN 200 ALL
NSF 1 ALL
RATIO 1 ALL
SMZ 1.4 ALL
SMY 1.4 ALL
SFT 1.3 ALL
SFC 1.3 ALL
TMAIN 300 ALL
TRACK 2 ALL
UNB 30 ALL
UNT 30 ALL
CT 0.75 ALL
CHECK CODE ALL
FINISH
STAAD Output
STAAD.PRO CODE CHECKING - ( ANSI N690-1994) v1.0 ******************************************** |--------------------------------------------------------------------------| | Y PROPERTIES | |************* | IN INCH UNIT | | * |=============================| ==| |== ------------ | |MEMBER 1 * | AISC SECTIONS | | | AX = 4.01 | | * | ST PIPS50 | | | --Z AY = 2.02 | |DESIGN CODE * | | | | AZ = 2.02 | |ANSI N690-94* =============================== ==| |== SY = 5.14 | | * SZ = 5.14 | | * |<---LENGTH (FT)= 10.00 --->| RY = 1.89 | |************* RZ = 1.89 | | | | 0.0 (KIP-FEET) | |PARAMETER |L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 STRESSES | |IN KIP INCH |L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 IN KIP INCH | |--------------- +L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 -------------| | KL/R-Y= 63.55 |L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 FA = 21.60 | | KL/R-Z= 63.55 +L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 fa = 2.49 | | UNL = 30.00 |L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 FCZ = 23.76 | | CB = 1.00 +L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 FTZ = 23.76 | | CMY = 1.00 |L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 FCY = 23.76 | | CMZ = 1.00 +L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 FTY = 23.76 | | FYLD = 36.00 |L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 fbz = 0.00 | | NSF = 1.00 +---+---+---+---+---+---+---+---+---+---| fby = 0.00 | | DFF = 0.00 0.0 Fey = 36.98 | | dff= 0.00 ABSOLUTE MZ ENVELOPE Fez = 36.98 | | (KL/R)max = 63.55 (WITH LOAD NO.) FV = 14.40 | | fv = 0.00 | | | | MAX FORCE/ MOMENT SUMMARY (KIP-FEET) | | ------------------------- | | | | AXIAL SHEAR-Y SHEAR-Z MOMENT-Y MOMENT-Z | | | | VALUE -10.0 0.0 0.0 0.0 0.0 | | LOCATION 0.0 0.0 0.0 0.0 0.0 | | LOADING 1 0 0 0 0 | | | |**************************************************************************| |* *| |* DESIGN SUMMARY (KIP-FEET) *| |* -------------- *| |* *| |* RESULT/ CRITICAL COND/ RATIO/ LOADING/ *| | FX MY MZ LOCATION | | ====================================================== | | PASS ANSI Q1.6-3 0.115 1 | | 10.00 T 0.00 0.00 0.00 | |* *| | | |--------------------------------------------------------------------------| STAAD SPACE -- PAGE NO. 7 70. * 71. LOAD LIST 2 72. PARAMETER 2 73. CODE AISC N690 1994 74. CB 1 ALL 75. CMY 1 ALL 76. CMZ 1 ALL 77. FYLD 36 ALL 78. FU 58 ALL 79. KY 1 ALL 80. KZ 1 ALL 81. MAIN 200 ALL 82. NSF 1 ALL 83. RATIO 1 ALL 84. TMAIN 300 ALL 85. TRACK 2 ALL 86. UNB 30 ALL 87. UNT 30 ALL 88. CT 0.75 ALL 89. CHECK CODE ALL STEEL DESIGN STAAD SPACE -- PAGE NO. 8 STAAD.PRO CODE CHECKING - ( ANSI N690-1994) v1.0 ******************************************** |--------------------------------------------------------------------------| | Y PROPERTIES | |************* | IN INCH UNIT | | * |=============================| ==| |== ------------ | |MEMBER 1 * | AISC SECTIONS | | | AX = 4.01 | | * | ST PIPS50 | | | --Z AY = 2.02 | |DESIGN CODE * | | | | AZ = 2.02 | |ANSI N690-94* =============================== ==| |== SY = 5.14 | | * SZ = 5.14 | | * |<---LENGTH (FT)= 10.00 --->| RY = 1.89 | |************* RZ = 1.89 | | | | 0.0 (KIP-FEET) | |PARAMETER |L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 STRESSES | |IN KIP INCH |L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 IN KIP INCH | |--------------- +L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 -------------| | KL/R-Y= 63.55 |L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 FA = 17.08 | | KL/R-Z= 63.55 +L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 fa = 2.49 | | UNL = 30.00 |L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 FCZ = 23.76 | | CB = 1.00 +L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 FTZ = 23.76 | | CMY = 1.00 |L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 FCY = 23.76 | | CMZ = 1.00 +L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 FTY = 23.76 | | FYLD = 36.00 |L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 L0 fbz = 0.00 | | NSF = 1.00 +---+---+---+---+---+---+---+---+---+---| fby = 0.00 | | DFF = 0.00 0.0 Fey = 36.98 | | dff= 0.00 ABSOLUTE MZ ENVELOPE Fez = 36.98 | | (KL/R)max = 63.55 (WITH LOAD NO.) FV = 14.40 | | fv = 0.00 | | | | MAX FORCE/ MOMENT SUMMARY (KIP-FEET) | | ------------------------- | | | | AXIAL SHEAR-Y SHEAR-Z MOMENT-Y MOMENT-Z | | | | VALUE 10.0 0.0 0.0 0.0 0.0 | | LOCATION 0.0 0.0 0.0 0.0 0.0 | | LOADING 2 0 0 0 0 | | | |**************************************************************************| |* *| |* DESIGN SUMMARY (KIP-FEET) *| |* -------------- *| |* *| |* RESULT/ CRITICAL COND/ RATIO/ LOADING/ *| | FX MY MZ LOCATION | | ====================================================== | | PASS ANSI Q1.6-2 0.146 2 | | 10.00 C 0.00 0.00 0.00 | |* *| | | |--------------------------------------------------------------------------| STAAD SPACE -- PAGE NO. 9 90. * 91. LOAD LIST 3 92. PARAMETER 3 93. CODE AISC N690 1994 94. CB 1 ALL 95. CMY 1 ALL 96. CMZ 1 ALL 97. FYLD 36 ALL 98. FU 58 ALL 99. KY 1 ALL 100. KZ 1 ALL 101. MAIN 200 ALL 102. NSF 1 ALL 103. RATIO 1 ALL 104. SMZ 1.4 ALL 105. SMY 1.4 ALL 106. SFT 1.3 ALL 107. SFC 1.3 ALL 108. TMAIN 300 ALL 109. TRACK 2 ALL 110. UNB 30 ALL 111. UNT 30 ALL 112. CT 0.75 ALL 113. CHECK CODE ALL STEEL DESIGN STAAD SPACE -- PAGE NO. 10 STAAD.PRO CODE CHECKING - ( ANSI N690-1994) v1.0 ******************************************** |--------------------------------------------------------------------------| | Y PROPERTIES | |************* | IN INCH UNIT | | * |=============================| ==| |== ------------ | |MEMBER 1 * | AISC SECTIONS | | | AX = 4.01 | | * | ST PIPS50 | | | --Z AY = 2.02 | |DESIGN CODE * | | | | AZ = 2.02 | |ANSI N690-94* =============================== ==| |== SY = 5.14 | | * SZ = 5.14 | | * |<---LENGTH (FT)= 10.00 --->| RY = 1.89 | |************* RZ = 1.89 | | | | 3.9 (KIP-FEET) | |PARAMETER | L3 STRESSES | |IN KIP INCH | IN KIP INCH | |--------------- + -------------| | KL/R-Y= 63.55 | L3 FA = 21.60 | | KL/R-Z= 63.55 + L3 fa = 2.49 | | UNL = 30.00 | L3 L3 FCZ = 23.76 | | CB = 1.00 + L3 L3 FTZ = 23.76 | | CMY = 1.00 | L3 L3 FCY = 23.76 | | CMZ = 1.00 + FTY = 23.76 | | FYLD = 36.00 |L0 L0 fbz = 9.15 | | NSF = 1.00 +---+---+---+---+---+---+---+---+---+---| fby = 0.00 | | DFF = 0.00 -0.2 Fey = 36.98 | | dff= 0.00 ABSOLUTE MZ ENVELOPE Fez = 36.98 | | (KL/R)max = 63.55 (WITH LOAD NO.) FV = 14.40 | | fv = 0.97 | | | | MAX FORCE/ MOMENT SUMMARY (KIP-FEET) | | ------------------------- | | | | AXIAL SHEAR-Y SHEAR-Z MOMENT-Y MOMENT-Z | | | | VALUE -10.0 2.0 0.0 0.0 3.9 | | LOCATION 0.0 10.0 0.0 0.0 10.0 | | LOADING 3 3 0 0 3 | | | |**************************************************************************| |* *| |* DESIGN SUMMARY (KIP-FEET) *| |* -------------- *| |* *| |* RESULT/ CRITICAL COND/ RATIO/ LOADING/ *| | FX MY MZ LOCATION | | ====================================================== | | PASS ANSI Q1.6-3 0.364 3 | | 10.00 T 0.00 3.92 10.00 | |* *| | | |--------------------------------------------------------------------------| STAAD SPACE -- PAGE NO. 11 114. * 115. LOAD LIST 4 116. PARAMETER 4 117. CODE AISC N690 1994 118. CB 1 ALL 119. CMY 1 ALL 120. CMZ 1 ALL 121. FYLD 36 ALL 122. FU 58 ALL 123. KY 1 ALL 124. KZ 1 ALL 125. MAIN 200 ALL 126. NSF 1 ALL 127. RATIO 1 ALL 128. SMZ 1.4 ALL 129. SMY 1.4 ALL 130. SFT 1.3 ALL 131. SFC 1.3 ALL 132. TMAIN 300 ALL 133. TRACK 2 ALL 134. UNB 30 ALL 135. UNT 30 ALL 136. CT 0.75 ALL 137. CHECK CODE ALL STEEL DESIGN STAAD SPACE -- PAGE NO. 12 STAAD.PRO CODE CHECKING - ( ANSI N690-1994) v1.0 ******************************************** |--------------------------------------------------------------------------| | Y PROPERTIES | |************* | IN INCH UNIT | | * |=============================| ==| |== ------------ | |MEMBER 1 * | AISC SECTIONS | | | AX = 4.01 | | * | ST PIPS50 | | | --Z AY = 2.02 | |DESIGN CODE * | | | | AZ = 2.02 | |ANSI N690-94* =============================== ==| |== SY = 5.14 | | * SZ = 5.14 | | * |<---LENGTH (FT)= 10.00 --->| RY = 1.89 | |************* RZ = 1.89 | | | | 3.9 (KIP-FEET) | |PARAMETER | L4 STRESSES | |IN KIP INCH | IN KIP INCH | |--------------- + -------------| | KL/R-Y= 63.55 | L4 FA = 17.08 | | KL/R-Z= 63.55 + L4 fa = 2.49 | | UNL = 30.00 | L4 L4 FCZ = 23.76 | | CB = 1.00 + L4 L4 FTZ = 23.76 | | CMY = 1.00 | L4 L4 FCY = 23.76 | | CMZ = 1.00 + FTY = 23.76 | | FYLD = 36.00 |L0 L0 fbz = 9.15 | | NSF = 1.00 +---+---+---+---+---+---+---+---+---+---| fby = 0.00 | | DFF = 0.00 -0.2 Fey = 36.98 | | dff= 0.00 ABSOLUTE MZ ENVELOPE Fez = 36.98 | | (KL/R)max = 63.55 (WITH LOAD NO.) FV = 14.40 | | fv = 0.97 | | | | MAX FORCE/ MOMENT SUMMARY (KIP-FEET) | | ------------------------- | | | | AXIAL SHEAR-Y SHEAR-Z MOMENT-Y MOMENT-Z | | | | VALUE 10.0 2.0 0.0 0.0 3.9 | | LOCATION 0.0 10.0 0.0 0.0 10.0 | | LOADING 4 4 0 0 4 | | | |**************************************************************************| |* *| |* DESIGN SUMMARY (KIP-FEET) *| |* -------------- *| |* *| |* RESULT/ CRITICAL COND/ RATIO/ LOADING/ *| | FX MY MZ LOCATION | | ====================================================== | | PASS ANSI Q1.6-2 0.387 4 | | 10.00 C 0.00 3.92 10.00 | |* *| | | |--------------------------------------------------------------------------| STAAD SPACE -- PAGE NO. 13 138. * 139. LOAD LIST ALL 140. PARAMETER 5 141. CODE AISC N690 1994 142. CB 1 ALL 143. CMY 1 ALL 144. CMZ 1 ALL 145. FYLD 36 ALL 146. FU 58 ALL 147. KY 1 ALL 148. KZ 1 ALL 149. MAIN 200 ALL 150. NSF 1 ALL 151. RATIO 1 ALL 152. SMZ 1.4 ALL 153. SMY 1.4 ALL 154. SFT 1.3 ALL 155. SFC 1.3 ALL 156. TMAIN 300 ALL 157. TRACK 2 ALL 158. UNB 30 ALL 159. UNT 30 ALL 160. CT 0.75 ALL 161. CHECK CODE ALL STEEL DESIGN STAAD SPACE -- PAGE NO. 14 STAAD.PRO CODE CHECKING - ( ANSI N690-1994) v1.0 ******************************************** |--------------------------------------------------------------------------| | Y PROPERTIES | |************* | IN INCH UNIT | | * |=============================| ==| |== ------------ | |MEMBER 1 * | AISC SECTIONS | | | AX = 4.01 | | * | ST PIPS50 | | | --Z AY = 2.02 | |DESIGN CODE * | | | | AZ = 2.02 | |ANSI N690-94* =============================== ==| |== SY = 5.14 | | * SZ = 5.14 | | * |<---LENGTH (FT)= 10.00 --->| RY = 1.89 | |************* RZ = 1.89 | | | | 3.9 (KIP-FEET) | |PARAMETER | L3 STRESSES | |IN KIP INCH | IN KIP INCH | |--------------- + -------------| | KL/R-Y= 63.55 | L3 FA = 17.08 | | KL/R-Z= 63.55 + L3 fa = 2.49 | | UNL = 30.00 | L3 L3 FCZ = 23.76 | | CB = 1.00 + L3 L3 FTZ = 23.76 | | CMY = 1.00 | L3 L3 FCY = 23.76 | | CMZ = 1.00 + FTY = 23.76 | | FYLD = 36.00 |L0 L0 fbz = 9.15 | | NSF = 1.00 +---+---+---+---+---+---+---+---+---+---| fby = 0.00 | | DFF = 0.00 -0.2 Fey = 36.98 | | dff= 0.00 ABSOLUTE MZ ENVELOPE Fez = 36.98 | | (KL/R)max = 63.55 (WITH LOAD NO.) FV = 14.40 | | fv = 0.97 | | | | MAX FORCE/ MOMENT SUMMARY (KIP-FEET) | | ------------------------- | | | | AXIAL SHEAR-Y SHEAR-Z MOMENT-Y MOMENT-Z | | | | VALUE -10.0 2.0 0.0 0.0 3.9 | | LOCATION 0.0 10.0 0.0 0.0 10.0 | | LOADING 1 3 0 0 3 | | | |**************************************************************************| |* *| |* DESIGN SUMMARY (KIP-FEET) *| |* -------------- *| |* *| |* RESULT/ CRITICAL COND/ RATIO/ LOADING/ *| | FX MY MZ LOCATION | | ====================================================== | | PASS ANSI Q1.6-2 0.387 4 | | 10.00 C 0.00 3.92 10.00 | |* *| | | |--------------------------------------------------------------------------|