A \frac{1}{2}-in by 2-in rectangular-cross-section 1015 bar carries a static load of 16.5 kip.
It is welded to a gusset plate with a \frac{3}{8}-in fillet weld 2 in long on both sides with an E70XX electrode as depicted in Fig. 9–18. Use the welding code method.
(a) Is the weld metal strength satisfactory?
(b) Is the attachment strength satisfactory?
(a) From Table 9–6, allowable force per unit length for a {3}{8}-in E70 electrode metal is
5.57 kip/in of weldment; thusF = 5.57l = 5.57 \left(4\right) = 22.28 \ kip
Table 9–6
Allowable Steady Loads and Minimum Fillet Weld Sizes
| Schedule A: Allowoble Load for Various Sixes of Fillet Welds | |||||||
| Strength Level of Weld Metal (EXX) | |||||||
| 60* | 70* | 80 | 90* | 100 | 110* | 120 | |
| Allowable shear stres. on throat. ksi ( I000 psi) of fillec weld or partial penetration groove weld | |||||||
| \tau= | 18.0 | 21.0 | 24.0 | 27.0 | 30.0 | 33.0 | 36.0 |
| Allowable Unj1 Force 011Fillec Weld.kip/l inear in | |||||||
| ^{†}f = | 12.73h | 14.85h | 16.97h | 19.09h | 21.21h | 23.33h | 25.45h |
| Leg Size h, in | |||||||
| Allowable Unit Force for Various Sizes of Fillet Welds kip/linear in | |||||||
| I | 12.73 | 14.85 | 16.97 | 19.09 | 21.2 1 | 23.33 | 25.45 |
| 7/8 | I 1.14 | 12.99 | 14.85 | 16.7 | 18.57 | 20.4 1 | 22.27 |
| 3/4 | 9.55 | 1 1.14 | 12.73 | 14.32 | 15.92 | 17.5 | 19.09 |
| 5/8 | 7.96 | 9.28 | 10.61 | I 1.93 | 13.27 | 14.58 | 15.91 |
| 1/2 | 6.37 | 7.42 | 8.48 | 9.54 | 10.61 | 1 1.67 | 12.73 |
| 7/16 | 5.57 | 6.5 | 7.42 | 8.35 | 9.28 | 10.2 1 | 1 1.14 |
| 3/8 | 4.77 | 5.57 | 6.36 | 7.16 | 7.95 | 8.75 | 9.54 |
| 5/16 | 3.98 | 4.64 | 5.3 | 5.97 | 6.63 | 7.29 | 1.95 |
| 1/4 | 3.18 | 3.71 | 4.24 | 4.77 | 5.3 | 5.83 | 6.36 |
| 3/16 | 2.39 | 2.78 | 3.18 | 3.58 | 3.98 | 4.38 | 4.77 |
| 1/8 | 1.59 | 1.86 | 2.12 | 2.39 | 2.65 | 2.92 | 3.18 |
| 1/16 | 0.795 | 0.93 | 1.06 | 1.19 | 1.33 | 1.46 | 1.59 |
| *Fillet welds actually tested by the joint AISC-AWS Task Committee. ^{†}f = 0.707h \tau_{all}. |
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Since 22.28 \gt 16.5 \ kip, weld metal strength is satisfactory.(b) Check shear in attachment adjacent to the welds. From Table A–20,S_y= 27.5 \ kpsi.
Then, from Table 9–4, the allowable attachment shear stress is
| Table A–20 | |||||||
| Deterministic ASTM Minimum Tensile and Yield Strengths for Some Hot-Rolled (HR) and Cold-Drawn (CD) Steels [The strengths listed are estimated ASTM minimum values in the size range 18 to 32 mm (\frac{3}{4}to 11 4in). These strengths are suitable for use with the design factor defined in Sec. 1–10, provided the materials conform to ASTM A6 or A568 requirements or are required in the purchase specifications. Remember that a numbering system is not a specification.] Source: 1986 SAE Handbook, p. 2.15. | |||||||
| 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 |
| UNS No. | SAE and/or AISI No. |
Processing | Tensile MPa (kpsi) Strength, |
Yield Strength, MPa (kpsi) |
Elongation in 2 in, % |
Reduction in Area, % |
Brinell Hardness |
| G10060 | 1006 | HR | 300 (43) | 170 (24) | 30 | 55 | 86 |
| CD | 330 (48) | 280 (41) | 20 | 45 | 95 | ||
| G10100 | 1010 | HR | 320 (47) | 180 (26) | 28 | 50 | 95 |
| CD | 370 (53) | 300 (44) | 20 | 40 | 105 | ||
| G10150 | 1015 | HR | 340 (50) | 190 (27.5) | 28 | 50 | 101 |
| CD | 390 (56) | 320 (47) | 18 | 40 | 111 | ||
| G10180 | 1018 | HR | 400 (58) | 220 (32) | 25 | 50 | 116 |
| CD | 440 (64) | 370 (54) | 15 | 40 | 126 | ||
| G10200 | 1020 | HR | 380 (55) | 210 (30) | 25 | 50 | 111 |
| CD | 470 (68) | 390 (57) | 15 | 40 | 131 | ||
| G10300 | 1030 | HR | 470 (68) | 260 (37.5) | 25 | 42 | 137 |
| CD | 520 (76) | 440 (64) | 15 | 35 | 149 | ||
| G10350 | 1035 | HR | 500 (72) | 270 (39.5) | 20 | 40 | 143 |
| CD | 550 (80) | 460 (67) | 12 | 35 | 163 | ||
| G10400 | 1040 | HR | 520 (76) | 290 (42) | 18 | 40 | 149 |
| CD | 590 (85) | 490 (71) | 12 | 35 | 170 | ||
| G10450 | 1045 | HR | 570 (82) | 310 (45) | 16 | 40 | 163 |
| CD | 630 (91) | 530 (77) | 12 | 35 | 179 | ||
| G10500 | 1050 | HR | 620 (90) | 340 (49.5) | 15 | 35 | 179 |
| CD | 690 (100) | 580 (84) | 10 | 30 | 197 | ||
| G10600 | 1060 | HR | 680 (98) | 370 (54) | 12 | 30 | 201 |
| G10800 | 1080 | HR | 770 (112) | 420 (61.5) | 10 | 25 | 229 |
| G10950 | 1095 | HR | 830 (120) | 460 (66) | 10 | 25 | 248 |
| Table 9–4 Stresses Permitted by the AISC Code for Weld Metal |
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| Type of Loading | Type of Weld | Permissible Stress | n* |
| tension | butt | 0.60 s_y | 1.67 |
| Bearing | Butt | 0.90 s_y | 1.11 |
| Bending | Butt | 0.60 – 0.66 S_y | 0.52-1.67 |
| Simple compression | Butt | 0.60 S_y | 1.67 |
| Shear | Butt or filter | 0.30S^†_{ut} | |
| *The factor of safety n has been computed by using the distortion-energy theory. †Shear stress on base metal should not exceed 0.40 S_y of base metal. |
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\tau_{all}= 0.4 S_y= 0.4 \left(27.5\right) = 11 \ kpsi
The shear stress \tau on the base metal adjacent to the weld is
\tau = \frac{F}{2hl}=\frac{16.5}{2\left(0.375\right)2}= 11 \ kpsi
Since \tau_{all} \ge \tau , the attachment is satisfactory near the weld beads.
The tensile stress in the shank of the attachment \sigma is
\sigma = \frac{F}{tl}= \frac{16.5}{\left({1}/{2}\right)2}= 16.5 \ kpsi
The allowable tensile stress σall, from Table 9–4, is 0.6 S_y and, with welding code safety level preserved,
\sigma_{all}= 0.6 S_y= 0.6 \left(27.5\right) = 16.5 \ psiSince \sigma \le \sigma_{all}, the shank tensile stress is satisfactory.