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如何设计单板剪切连接

To design a single plate shear connection (a shear tab) 到美国钢铁协会 360, you check the bolts, the plate and the weld against the beam end reaction. That means bolt shear, 螺栓轴承和撕裂, 块剪, plate shear yielding and rupture, 板弯曲, and weld strength, plus the detailing and ductility limits that keep the connection flexible enough to act as a simple support.

This page works through one real example from start to finish: a W18x35 beam framing into the flange of a W14x90 column, 与一个 50 kip LRFD reaction, 三 1 in A490-N bolts and a 1/2 在盘子里, 设计符合 AISC 360-16 和 AISC 手册第 15 版. 每个方程都用它的数字写出来, 按照与 AISC 计算表相同的顺序 SkyCiv连接设计 模块为其生成.

What is a single plate shear connection?

A single plate shear connection is a steel plate shop-welded to the supporting member and field-bolted to the web of the supported beam. It transfers the beam’s end shear, and it is classified as a simple connection under AISC 360-16 B3.4, so it is detailed to rotate rather than resist moment. It is also called a shear tab or shear plate.

It is the most common 剪力连接 in US steel buildings because it needs one plate, one weld and one line of bolts, and the beam can be swung into place from the side during erection. The alternatives for the same job are the double angle connection, 的 single angle connection and the shear end plate connection. You can check this one directly in the 单板连接计算器.

单板剪力连接立面图: A992 W18x35 beam bolted to a 1/2 in shear tab welded to an A992 W14x90 column flange, 三 1 in A490-N bolts at 3 在间距

Elevation of the example connection. The plate is welded to the column flange and bolted to the beam web, with the bolt line 2 in from the weld.

Section A-A through the shear tab showing the 1/2 in x 3 1/2 在x 9 in A572 Grade 50 plate with 5/16 in E70XX fillet welds both sides

A-A部分. The plate has horizontal short-slotted holes and a 5/16 in fillet weld on both sides.

How do you design a single plate shear connection? The steps at a glance

  1. Check the detailing limits at the beam: 螺栓间距, 边缘距离, plate depth.
  2. Find the bolt group shear strength with the instantaneous center of rotation.
  3. Check plate ductility: the plate must not be stronger than the bolts.
  4. Check bolt bearing and tear-out on the plate.
  5. Check bolt bearing and tear-out on the beam web.
  6. Combine shear, bearing and tear-out per bolt for the effective group strength.
  7. Check block shear of the plate.
  8. Check shear yielding and shear rupture of the plate.
  9. Check plate flexure using the double coped beam procedure.
  10. Check shear and flexure interaction, for yielding and for rupture.
  11. Check the detailing limit at the support.
  12. Size the weld to develop the plate.
  13. Check the weld strength to the column flange.

本示例的设计输入

设计代码为AISC 360-16 LRFD. 截面属性来自 AISC 手册.

物品 象征 值
Factored vertical shear [mathin] V_{u} [mathin] 50 基普
光束 W18x35, A992
Beam depth [mathin] d_{bm} [mathin] 17.7 在
Beam web thickness [mathin] t_{wb} [mathin] 0.3 在
Beam flange width / 厚度 [mathin] b_{fb},\ t_{fb} [mathin] 6 在 / 0.425 在
Beam yield / 拉应力 [mathin] F_{yb},\ F_{ub} [mathin] 50 KSI / 65 KSI
柱 AISC 连接设计示例, A992
Column flange thickness [mathin] t_{fs} [mathin] 0.71 在
Column yield / 拉应力 [mathin] F_{ys},\ F_{us} [mathin] 50 KSI / 65 KSI
Modulus of elasticity [mathin] E [mathin] 29000 KSI

 

物品 象征 值
盘子 (单板) PL 1/2 X 3 1/2 X 9, A572组. 50
Plate width / 深度 / 厚度 [mathin] b_{p},\ d_{p},\ t_{p} [mathin] 3.5 在 / 9 在 / 0.5 在
板材产量 / 拉应力 [mathin] F_{yp},\ F_{up} [mathin] 50 KSI / 65 KSI
螺栓 1 in A490-N, single shear
螺栓直径 [mathin] d_{b} [mathin] 1 在
螺栓公称拉力 / 剪应力 [mathin] F_{nt},\ F_{nv} [mathin] 113 KSI / 68 KSI
Shear planes [mathin] N_{s} [mathin] 1
板中的孔 / 光束 Short-slotted horizontal (高速SSL) / 标准 (性病)
焊接 5/16 in fillet, both sides, E70XX
焊缝尺寸 / filler strength [mathin] W,\ F_{EXX} [mathin] 0.3125 在 / 70 KSI

 

几何 象征 值
螺栓排 / 行距 [mathin] n_{r},\ s_{r} [mathin] 3 / 3 在
螺栓柱 / 列间距 [mathin] n_{c},\ s_{c} [mathin] 1 / 0 在
Beam web clearance to column [mathin] clr [mathin] 0.5 在
Horizontal edge distance on beam web [mathin] L_{eh,bm} [mathin] 1.5 在
Horizontal edge distance on plate [mathin] L_{eh,pl} [mathin] 1.5 在
Vertical edge distance on plate [mathin] L_{ev,pl} [mathin] 1.5 在
Weld line to bolt line [mathin] a = e [mathin] 2 在

步 1: Detailing limits at the beam side (AISC 360-16 J3.3, J3.4)

在进行任何力量检查之前, the bolt layout has to be buildable and match the assumptions behind the strength equations. Bolts that are too close tear between the holes, edges that are too close tear out, and a plate that is too short or too deep changes how the connection rotates.

最小螺栓间距为 [mathin] 2\tfrac{2}{3} d_{b} [mathin] from J3.3. The minimum edge distance for a 1 in bolt is 1 1/4 in from Table J3.4. On the plate, the horizontal edge is measured across the short slot, so the Table J3.5 increment raises it to 1.375 在. The plate depth has to be at least half the beam’s T dimension, so the connection is stiff enough to brace the beam end, and it must also fit inside the beam web.

[math] s_{min} = 2\tfrac{2}{3}\, d_{b} = 2.667 \times (1\,in) = 2.667\,in [math]

详细限制 限制 (在) 实际的 (在) 直流电 结果
最小螺栓排间距 2.667 3.000 0.889 通过
最大螺栓排间距 6.000 3.000 0.500 通过
Plate minimum vertical edge distance 1.250 1.500 0.833 通过
Plate minimum horizontal edge distance 1.375 1.500 0.917 通过
Beam minimum horizontal edge distance 1.250 1.500 0.833 通过
最小连接深度 7.750 9.000 0.861 通过
最大连接深度 16.000 9.000 0.563 通过

For a minimum limit the ratio is limit over actual, and for a maximum it is actual over limit. The governing row is the plate horizontal edge distance:

[math] DCR = \frac{1.375\,in}{1.5\,in} = 0.917 [math]

DCR = 0.917 < 1.0, 行

步 2: Bolt group shear strength by the instantaneous center of rotation (AISC 360-16 J3.6)

The beam reaction acts away from the bolt line, so the bolts carry a small moment as well as the shear. 瞬时旋转中心 (ICOR) method finds the point the bolt group rotates about and turns that into a coefficient C, which is how many bolts’ worth of shear strength the group actually delivers.

设计偏心率

The bolt line is 2 in from the weld, but the bolt group is designed for an eccentricity of 1 在, because AISC Manual Table 10-9 设置传统单板连接的设计偏心率, and for this bolt count and hole type it is half the weld-to-bolt distance:

[math] e = \frac{a}{2} = \frac{2\,in}{2} = 1\,in [math]

Strength of one bolt

[math] \phi r_{v} = \phi\, F_{nv}\, \frac{\pi}{4} d_{b}^{2}\, N_{s}\, h_{f} [math]

[math] \phi r_{v} = (0.75) \times (68\,ksi) \times \frac{\pi}{4} (1\,in)^{2} \times (1) \times (1) = 40.055\,kip [math]

这里 [mathin] h_{f} = 1 [mathin] because there are no fillers (AISC 360-16 J5.2(一个)):

[math] h_{f} = 1 – 0.4 \left( t – 0.25\,in \right) = 1 – 0.4 \left( 0\,in – 0.25\,in \right) \le 1 \;\Rightarrow\; h_{f} = 1 [math]

Locating the instantaneous center

螺栓 1 is at the bottom of the line, with the coordinates below. The IC is found by iteration, using the load-deformation curve of AISC Manual Equation (7-1) 在页面上 7-6 至 7-8. 的 使用 ICOR 进行螺栓组计算 walks through that iteration in full.

螺栓 X (在) 和 (在)
1 0.00 0.00
2 0.00 3.00
3 0.00 6.00

The iteration converges with the IC at:

[math] x_{ic} = -5.7728\,in, \qquad y_{ic} = 3\,in [math]

The bolt reactions at that location are:

螺栓 [R (基普) 接收 (基普) 瑞 (基普) Mn (小鸡)
1 39.31 18.13 34.88 255.77
2 38.97 0.00 38.97 224.94
3 39.31 -18.13 34.88 255.77

That gives the two coefficients used in the rest of the design:

[math] C = 2.71 \qquad C’ = 5.889\,in [math]

C = 2.71 for three bolts means the 1 in eccentricity costs the group about 10% of its concentric strength. C’ is the coefficient for moment alone, which the ductility check in Step 3 用途.

Bolt group strength

[math] \phi R_{n} = \phi\, F_{nv}\, \frac{\pi}{4} d_{b}^{2}\, N_{s}\, C\, h_{f} [math]

[math] \phi R_{n} = (0.75) \times (68\,ksi) \times \frac{\pi}{4} (1\,in)^{2} \times (1) \times (2.71) \times (1) [math]

[math] \phi R_{n} = 108.55\,kip [math]

DCR = 50 基普 / 108.55 基普= 0.461 < 1.0, 行

步 3: 板材延展性, maximum plate thickness (AISC Manual Eq. 10-3, 10-4)

A shear tab has to rotate as the beam deflects. 如果板的弯曲强度大于螺栓的剪切强度, the bolts fracture before the plate yields, which is a sudden, brittle failure. Capping the plate thickness makes sure the plate yields first.

第一, the moment strength of the bolt group, using C’ from Step 2:

[math] M_{max} = \frac{F_{nv}}{0.90}\, \frac{\pi}{4} d_{b}^{2}\, C’ [math]

[math] M_{max} = \frac{68\,ksi}{0.90} \times \frac{\pi}{4} (1\,in)^{2} \times (5.889\,in) = 29.122\,kip\text{-}ft [math]

Then the thickest plate whose plastic moment does not exceed it:

[math] t_{max} = \frac{6\, M_{max}}{F_{yp}\, d_{p}^{2}} [math]

[math] t_{max} = \frac{6 \times (29.122\,kip\text{-}ft)}{(50\,ksi) \times (9\,in)^{2}} = 0.51772\,in [math]

DCR = 0.5 在 / 0.51772 在 = 0.966 < 1.0, 行

在 0.966 this is the tightest strength check in the connection. 一个 5/8 in plate would fail it, even though a thicker plate looks “更强”.

步 4: Bolt bearing and tear-out on the single plate (AISC 360-16 J3.10)

Each bolt pushes down on the edge of its hole in the plate. The plate either deforms at the hole (轴承, capped at 2.4 螺栓的剪切强度) or tears a strip out to the next hole or to the bottom edge (撕掉, 1.2 螺栓的剪切强度). The bottom bolt has the shortest clear distance, so it is the weak one.

Clear distance for the edge bolt, 与 [mathin] d_{h} = 1.125\,in [mathin], the hole dimension across the member length:

[math] l_{c1} = L_{ev,pl} – \frac{d_{h}}{2} = 1.5\,in – \frac{1.125\,in}{2} = 0.9375\,in [math]

Clear distance between the inner bolts:

[math] l_{c2} = s_{r} – d_{h} = 3\,in – 1.125\,in = 1.875\,in [math]

The bearing and tear-out strength of the group, scaled by C / n for the eccentricity:

[math] \phi R_{n} = \phi \left[ \min\left(1.2\, l_{c1},\, 2.4\, d_{b}\right) t_{p} F_{up} + \min\left(1.2\, l_{c2},\, 2.4\, d_{b}\right) t_{p} F_{up} \left( n_{r} – 1 \right) \right] \frac{C}{n_{r}} [math]

[math] \phi R_{n} = (0.75) \left[ \min\left(1.125,\, 2.4\right)(0.5)(65) + \min\left(2.25,\, 2.4\right)(0.5)(65)(3 – 1) \right] \times \frac{2.71}{3} [math]

[math] \phi R_{n} = 123.86\,kip [math]

DCR = 50 基普 / 123.86 基普= 0.404 < 1.0, 行

步 5: Bolt bearing and tear-out on the beam web (AISC 360-16 J3.10)

The same check applies to the beam web. The beam is not coped and its bottom flange is far below the bolts, so there is no edge to tear out to, and every bolt bears like an inner bolt.

[math] l_{c2} = s_{r} – d_{h} = 3\,in – 1.125\,in = 1.875\,in [math]

[math] \phi R_{n} = \phi\, \min\left(1.2\, l_{c2},\, 2.4\, d_{b}\right) t_{wb} F_{ub}\, C [math]

[math] \phi R_{n} = (0.75) \times \min\left(1.2 \times 1.875\,in,\, 2.4 \times 1\,in\right) \times (0.3\,in) \times (65\,ksi) \times (2.71) [math]

[math] \phi R_{n} = 89.176\,kip [math]

DCR = 50 基普 / 89.176 基普= 0.561 < 1.0, 行

The beam web and the plate have the same tensile strength (65 KSI), 但是 0.3 in web is thinner than the 1/2 在盘子里, so the web has the lower capacity of the two.

步 6: Effective strength of the bolt group (AISC 360-16 J3.6 评论)

螺栓剪, bearing and tear-out are not really separate checks. Each bolt delivers the least of its shear strength and its bearing or tear-out strength in each ply it passes through, and the group strength is the sum of those per-bolt values.

The per-bolt bearing and tear-out strengths, for the plate edge bolt, a plate inner bolt and the beam web:

[math] \phi r_{n1e} = \phi\, \min\left(1.2\, l_{c1},\, 2.4\, d_{b}\right) t_{p} F_{up} = (0.75) \times \min\left(1.125\,in,\, 2.4\,in\right) \times (0.5\,in) \times (65\,ksi) = 27.422\,kip [math]

[math] \phi r_{n1i} = \phi\, \min\left(1.2\, l_{c2},\, 2.4\, d_{b}\right) t_{p} F_{up} = (0.75) \times \min\left(2.25\,in,\, 2.4\,in\right) \times (0.5\,in) \times (65\,ksi) = 54.844\,kip [math]

[math] \phi r_{n2} = \phi\, \min\left(1.2\, l_{c2},\, 2.4\, d_{b}\right) t_{wb} F_{ub} = (0.75) \times \min\left(2.25\,in,\, 2.4\,in\right) \times (0.3\,in) \times (65\,ksi) = 32.906\,kip [math]

Bolts are numbered from the top of the line here, so bolt 3 is the edge bolt on the plate:

螺栓 螺栓剪 (基普) 轴承 / 撕掉, 盘子 (基普) 轴承 / 撕掉, beam web (基普) Effective strength (基普)
1 40.06 54.84 32.91 32.91
2 40.06 54.84 32.91 32.91
3 40.06 27.42 32.91 27.42

[math] \sum \phi r_{eff} = n_{1}\, \phi r_{eff,1} + n_{2}\, \phi r_{eff,2} = (2) \times (32.906\,kip) + (1) \times (27.422\,kip) = 93.234\,kip [math]

[math] \phi R_{n,eff} = \frac{C}{n_{r}} \sum \phi r_{eff} = \frac{2.71}{3} \times (93.234\,kip) = 84.222\,kip [math]

DCR = 50 基普 / 84.222 基普= 0.594 < 1.0, 行

None of the three bolts is limited by AISC bolt shear. Bearing in the beam web and tear-out at the bottom of the plate govern, which is typical when the bolts are high-strength and the plies are thin. You can run the same connection in the free connection design calculator and change the bolt grade or the plate edge distance to see which bolt moves.

步 7: Block shear of the single plate (AISC 360-16 J4.3)

A block of the plate can tear out along the bolt line: shear down the line of holes plus tension across the short leg to the plate’s free edge. With one bolt column this is an L-shaped block.

The net tension area uses the hole dimension along the member length, [mathin] d_{h} = 1.3125\,in [mathin], because the slots run horizontally. Each hole adds 1/16 in for damage during punching (B4.3):

[math] A_{nt} = t_{p} \left[ (n_{c}-1)\, s_{c} + L_{eh,pl} – (n_{c} – 0.5)\left( d_{h} + 0.0625\,in \right) \right] [math]

[math] A_{nt} = (0.5\,in) \times \left[ (0)(0\,in) + 1.5\,in – (0.5)(1.3125\,in + 0.0625\,in) \right] = 0.40625\,in^{2} [math]

Gross and net shear areas, 与 [mathin] d_{h} = 1.125\,in [mathin] across the member length:

[math] A_{gv} = t_{p} \left[ L_{ev,pl} + (n_{r}-1)\, s_{r} \right] = (0.5\,in) \times \left[ 1.5\,in + (2)(3\,in) \right] = 3.75\,in^{2} [math]

[math] A_{nv} = t_{p} \left[ d_{p} – L_{ev,pl} – (n_{r} – 0.5)\left( d_{h} + 0.0625\,in \right) \right] = (0.5\,in) \times \left[ 9\,in – 1.5\,in – (2.5)(1.1875\,in) \right] = 2.2656\,in^{2} [math]

Block shear strength, 与 [mathin] U_{bs} = 1 [mathin] for uniform tension:

[math] \phi R_{n} = \phi \left( 0.6\, F_{up} A_{nv} + U_{bs} F_{up} A_{nt} \right) \le \phi \left( 0.6\, F_{yp} A_{gv} + U_{bs} F_{up} A_{nt} \right) [math]

[math] \phi R_{n} = (0.75) \left( 0.6 \times 65 \times 2.2656 + 1 \times 65 \times 0.40625 \right) \le (0.75) \left( 0.6 \times 50 \times 3.75 + 1 \times 65 \times 0.40625 \right) [math]

[math] \phi R_{n} = 86.074\,kip [math]

DCR = 50 基普 / 86.074 基普= 0.581 < 1.0, 行

步 8: Shear yielding and shear rupture of the single plate (AISC 360-16 J4.2)

The full reaction passes through the plate as vertical shear. The gross section must not yield, and the net section through the bolt holes must not rupture.

剪切屈服 (情商. J4-3)

[math] A_{gv} = d_{p}\, t_{p} = (9\,in) \times (0.5\,in) = 4.5\,in^{2} [math]

[math] \phi R_{n,sy} = \phi\, 0.6\, F_{yp} A_{gv} = (1.00) \times 0.6 \times (50\,ksi) \times (4.5\,in^{2}) = 135\,kip [math]

剪切断裂 (情商. J4-4)

[math] A_{nv} = t_{p} \left[ d_{p} – n_{r}\left( d_{h} + 0.0625\,in \right) \right] = (0.5\,in) \times \left[ 9\,in – 3 \times (1.1875\,in) \right] = 2.7188\,in^{2} [math]

[math] \phi R_{n,sr} = \phi\, 0.6\, F_{up} A_{nv} = (0.75) \times 0.6 \times (65\,ksi) \times (2.7188\,in^{2}) = 79.523\,kip [math]

[math] \phi R_{n} = \min\left( 135\,kip,\, 79.523\,kip \right) = 79.523\,kip [math]

DCR = 50 基普 / 79.523 基普= 0.629 < 1.0, 行

步 9: Plate flexure using the double coped beam procedure (AISC 360-16 F11.2)

The reaction acts 2 in from the weld, so the plate is a short cantilever in bending. 一个深, thin plate can buckle sideways before it yields. The AISC Manual handles this with the procedure for a coped beam coped at both flanges, treating the plate like a beam web with the flanges cut away. The unbraced length is the weld-to-bolt distance, [mathin] L_{b} = 2\,in [mathin].

Flexural yielding and lateral-torsional buckling

第一, confirm the plate is in the range where Eq. F11-2 applies:

[math] \frac{L_{b} d}{t^{2}} = \frac{(2\,in)(9\,in)}{(0.5\,in)^{2}} = 72 [math]

[math] \frac{0.08 E}{F_{y}} = \frac{0.08 \times 29000\,ksi}{50\,ksi} = 46.4 \lt 72 \le \frac{1.9 E}{F_{y}} = \frac{1.9 \times 29000\,ksi}{50\,ksi} = 1102 [math]

Section moduli of the plate:

[math] Z = \frac{t_{p} d_{p}^{2}}{4} = \frac{(0.5\,in)(9\,in)^{2}}{4} = 10.125\,in^{3} \qquad S = \frac{t_{p} d_{p}^{2}}{6} = \frac{(0.5\,in)(9\,in)^{2}}{6} = 6.75\,in^{3} [math]

Lateral-torsional buckling modification factor, AISC Manual Eq. (9-15), with no cope ([mathin] d_{ct} = 0 [mathin]):

[math] C_{b} = \left[ 3 + \ln\left( \frac{L_{b}}{d_{p}} \right) \right] \left( 1 – \frac{d_{ct}}{d_{p}} \right) \ge 1.84 [math]

[math] C_{b} = \left[ 3 + \ln\left( \frac{2\,in}{9\,in} \right) \right] \times \left( 1 – \frac{0\,in}{9\,in} \right) \ge 1.84 \;\Rightarrow\; C_{b} = 1.84 [math]

[math] \phi M_{n} = \phi\, C_{b} \left[ 1.52 – 0.274 \left( \frac{L_{b} d}{t^{2}} \right) \left( \frac{F_{yp}}{E} \right) \right] F_{yp} S \le \phi\, F_{yp} Z [math]

[math] \phi M_{n} = (0.9)(1.84) \left[ 1.52 – 0.274 \times (72) \times \frac{50\,ksi}{29000\,ksi} \right] (50\,ksi)(6.75\,in^{3}) \le (0.9)(50\,ksi)(10.125\,in^{3}) [math]

[math] \phi M_{n} = 37.969\,kip\text{-}ft \;(455.6\,kip\text{-}in) [math]

The plastic moment cap governs, so the plate is not prone to buckling at this depth and thickness. As an equivalent shear at the bolt line:

[math] \phi V_{n,y} = \frac{\phi M_{n}}{L_{b}} = \frac{455.6\,kip\text{-}in}{2\,in} = 227.81\,kip [math]

Flexural rupture on the net section

The net plastic section modulus through the holes, from AISC Manual Part 15 桌子 15-3:

[math] Z_{net} = \frac{t_{p} d_{p}^{2}}{4} – t_{p}\left( d_{h} + 0.0625\,in \right) s_{r} \left\lfloor \frac{n_{r}^{2}}{4} \right\rfloor – \left[ n_{r}\ \text{odd} \right] \frac{t_{p}\left( d_{h} + 0.0625\,in \right)^{2}}{4} [math]

[math] Z_{net} = \frac{(0.5)(9)^{2}}{4} – (0.5)(1.1875)(3) \left\lfloor \frac{9}{4} \right\rfloor – (1) \frac{(0.5)(1.1875)^{2}}{4} = 6.3862\,in^{3} [math]

[math] \phi M_{n} = \phi\, F_{up} Z_{net} = (0.75) \times (65\,ksi) \times (6.3862\,in^{3}) = 25.944\,kip\text{-}ft \;(311.3\,kip\text{-}in) [math]

[math] \phi V_{n,r} = \frac{\phi M_{n}}{L_{b}} = \frac{311.3\,kip\text{-}in}{2\,in} = 155.66\,kip [math]

[math] \phi V_{n} = \min\left( 227.81\,kip,\, 155.66\,kip \right) = 155.66\,kip [math]

DCR = 50 基普 / 155.66 基普= 0.321 < 1.0, 行

步 10: Shear and flexure interaction of the single plate (AISC Manual Part 10)

The plate carries shear and bending at the same section at the same time, so the two have to be checked together. The Manual uses a circular interaction, done once with the yielding strengths and once with the rupture strengths.

屈服

[math] \left( \frac{V_{u}}{\phi V_{n,y}} \right)^{2} + \left( \frac{V_{u}}{\phi R_{n,sy}} \right)^{2} = \left( \frac{50\,kip}{227.81\,kip} \right)^{2} + \left( \frac{50\,kip}{135\,kip} \right)^{2} = 0.185 [math]

DCR = 0.185 < 1.0, 行

破裂

[math] \left( \frac{V_{u}}{\phi V_{n,r}} \right)^{2} + \left( \frac{V_{u}}{\phi R_{n,sr}} \right)^{2} = \left( \frac{50\,kip}{155.66\,kip} \right)^{2} + \left( \frac{50\,kip}{79.523\,kip} \right)^{2} = 0.498 [math]

DCR = 0.498 < 1.0, 行

步 11: Detailing limit at the support side

The fillet weld sits in the gap between the column flange and the end of the beam, so the weld cannot be larger than the beam clearance or the beam will not fit.

[math] DCR = \frac{W}{clr} = \frac{0.3125\,in}{0.5\,in} = 0.626 [math]

DCR = 0.626 < 1.0, 行

步 12: Weld required to develop the single plate (AISC Manual Part 10)

The ductility check in Step 3 makes the plate yield first. That only works if the weld does not fail before the plate does. Two fillet welds, each at least 5/8 of the plate thickness, develop the plate’s strength.

[math] W_{min} = \frac{5}{8}\, t_{p} = \frac{5}{8} \times (0.5\,in) = 0.3125\,in [math]

DCR = 0.3125 在 / 0.3125 在 = 1.000, 行

正好有一个比例 1.000 is normal here. 的 5/16 in weld was picked from this rule, not from the load.

步 13: Fillet weld capacity to the column flange (AISC 360-16 J2.4)

最后的, the welds have to carry the reaction itself. Their strength depends on size, length and load direction. The base metal on either side of the weld, here the plate and the column flange, can also limit how much of the weld size counts.

Base metal limit on weld size (AISC Manual Eq. 9-2)

The largest weld size, in sixteenths of an inch, that the thinner connected part can support. The plate is welded both sides, so half its thickness is available to each weld:

[math] D_{max} = \frac{ \min\left( \frac{t_{p}}{2} F_{up},\; t_{fs} F_{us} \right) }{3.09\,kip/in \times \left( F_{EXX} / 70\,ksi \right)} = \frac{ \min\left( (0.25\,in)(65\,ksi),\; (0.71\,in)(65\,ksi) \right) }{(3.09\,kip/in)(1)} = 5.2589 [math]

So up to 5.26/16 in of weld size counts. 的 5/16 in weld is below that, so the full size is used.

Effective length

Two lines of weld, each reduced by 2W at the ends:

[math] L_{w} = 2 \left( d_{p} – 2W \right) = 2 \times \left[ 9\,in – 2 \times (0.3125\,in) \right] = 16.75\,in [math]

焊接强度

The load runs parallel to the welds, 所以 [mathin] \theta = 0 [mathin] 并且没有定向增加:

[math] \phi R_{n} = \phi\, 0.6\, F_{EXX} \frac{\sqrt{2}}{2} \min\left( W,\, \frac{D_{max}}{16} \right) \left[ 1 + 0.5 \sin^{1.5}\theta \right] L_{w} [math]

[math] \phi R_{n} = (0.75) \times 0.6 \times (70\,ksi) \times \frac{\sqrt{2}}{2} \times (0.3125\,in) \times \left[ 1 + 0.5 \sin^{1.5}(0) \right] \times (16.75\,in) [math]

[math] \phi R_{n} = 116.59\,kip [math]

DCR = 50 基普 / 116.59 基普= 0.429 < 1.0, 行

设计检查总结

设计检查 需求 容量 直流电 结果
Detailing limits at beam side 1.375 在 1.500 在 0.917 通过
Bolt group shear 50.000 基普 108.550 基普 0.461 通过
延展性 (maximum plate thickness) 0.500 在 0.518 在 0.966 通过
螺栓轴承和撕裂, 单板 50.000 基普 123.855 基普 0.404 通过
螺栓轴承和撕裂, beam web 50.000 基普 89.176 基普 0.561 通过
Effective strength of bolt group 50.000 基普 84.222 基普 0.594 通过
Block shear of single plate 50.000 基普 86.074 基普 0.581 通过
Shear yielding and rupture of single plate 50.000 基普 79.523 基普 0.629 通过
Plate flexure (double coped procedure) 50.000 基普 155.664 基普 0.321 通过
剪切和弯曲相互作用, 屈服 0.185 1.000 0.185 通过
剪切和弯曲相互作用, 破裂 0.498 1.000 0.498 通过
Detailing limits at support side 0.313 在 0.500 在 0.626 通过
Weld to develop single plate 0.313 在 0.313 在 1.000 通过
Weld to support flange 50.000 基普 116.590 基普 0.429 通过

The connection passes every check. Two ratios sit near 1.0, and neither one measures load against capacity. The weld-to-develop check is exactly 1.000 because the weld was sized from the 5/8 t rule, and the ductility check is 0.966 because a 1/2 in plate is just under the thickest plate that still yields before the bolts break. Of the checks that compare load with capacity, shear rupture of the plate (0.629) is the highest, closely followed by the effective bolt group strength (0.594), which is set by bearing in the 0.3 in beam web and tear-out at the bottom of the plate.

如果检查失败要更改什么

  • Bolt group shear or effective strength: 添加螺栓行, which raises C, or use a larger bolt. Moving the bolt line closer to the weld reduces e and raises C.
  • 延展性 (t_max): use a thinner plate, or a lower-strength plate grade. A thicker plate makes this check worse.
  • Tear-out on the plate: increase the vertical edge distance below the bottom bolt.
  • Bearing on the beam web: this depends on the web thickness and grade, so add a bolt row or pick a heavier beam.
  • 块剪, shear rupture or flexural rupture: make the plate deeper with another bolt row, or make it thicker if the ductility check has room.
  • Weld to develop the plate: increase the weld to 5/8 of the plate thickness, provided it still fits within the beam clearance.

经常问的问题

Why is the bolt group designed for a 1 in eccentricity when the bolts are 2 in from the weld?

AISC 手册表 10-9 sets the design eccentricity for a conventional single plate connection based on the number of bolts and the hole type. For this three-bolt connection it is half the distance from the weld line to the bolt line, 所以 2 in becomes 1 在. The weld is then designed for the reaction alone. This calibration comes from tests on real shear tabs, which rotate and shed most of the end moment.

What is the difference between the conventional and extended single plate configurations?

The conventional configuration covers a single vertical row of 2 至 12 bolts with the bolt line no more than 3 1/2 in from the weld, plus the edge distance and thickness limits in Part 10 AISC 手册. Within those limits, the simplified Table 10-9 approach in this example applies. Anything outside them, such as a longer plate reaching past a column flange to a deeper bolt line, is the extended configuration and needs a fuller analysis including plate buckling.

Why does the plate use short-slotted holes?

Horizontal short slots in the plate let the beam end rotate and give the erector some fit-up tolerance, both of which suit a simple connection. Because the slots run perpendicular to the vertical load, the bearing and tear-out checks use the hole dimension across the slot. The horizontal edge distance on the plate picks up a small increment from Table J3.5, which is why its limit is 1.375 in rather than 1.25 在.

Why is the fillet weld sized at 5/8 of the plate thickness?

The design relies on the plate yielding before anything brittle happens. Two fillet welds, 每个 5/8 of the plate thickness, are strong enough to develop the plate, so the weld cannot become the weak link even if the plate yields. 为一个 1/2 in plate that gives a 5/16 in weld, which is why that check lands at exactly 1.0.

Which check usually governs a shear tab?

For a typical shear tab with high-strength bolts, bearing or tear-out on the thinner ply and the ductility limit on plate thickness tend to govern rather than bolt shear. In this example the highest load ratio is plate shear rupture at 0.629, with the effective bolt group strength next at 0.594, controlled by bearing in the beam web. The ductility check sits at 0.966.

此示例是否遵循 AISC 第 15 版或 AISC 第 16 版手册?

它遵循 AISC 360-16 和 AISC 手册第 15 版, 这是围绕该规范编写的. AISC 第 16 版手册与后续版本配对 360-22 规范. The limit states for a single plate shear connection are the same in both, but clause and page references move, 因此请根据您的项目使用的版本检查它们.

对于 AISC ASD 而不是 LRFD 来说,这会如何变化?

The limit states and nominal strengths are identical. With AISC ASD you compare the service-level reaction against the nominal strength divided by a safety factor instead of multiplying by a resistance factor. 阻力系数为 0.75 成为安全系数 2.00, and shear yielding’s 1.00 变成 1.50. 荷载组合也发生变化, so the demand is lower.

Is the column checked in this design?

The column flange enters through the weld base metal check in Step 13, where its thickness and tensile strength limit the usable weld size. In this example the plate, not the 0.71 in column flange, controls that limit. Column web and flange local limit states are not part of this single plate check.

Design a single plate shear connection for free

此页上的每个数字都来自一个解决方案. Pick the single plate configuration, 输入你的光束, 支持, bolts and reaction, 并在浏览器中查看每项检查. 没有什么可安装的.

SkyCiv Connection Design 模块是本示例背后的连接设计软件. 它为您提供完整的计算报告,其中包含每个方程和您的数字, 就像上面的步骤一样, 加上每个容量和 DCR, 对于AISC 360-16 (LRFD 和 ASD) 并作为 4100:2020. 的 螺栓计算器 和 焊接计算器 cover the bolt group and weld checks on their own.

参考资料

  • AISC 360-16, 钢结构建筑规范: B3.4, B4.3, F11.2 (情商. F11-2), J2.4 (情商. J2-4), J3.3, J3.4 (表J3.4), J3.5 (表 J3.5), J3.6 (情商. J3-1) 及评论, J3.10 (情商. J3-6a, J3-6c), J4.2 (情商. J4-3, J4-4), J4.3 (情商. J4-5), J5.2(一个).
  • AISC 钢结构手册, 15第版: 部分 7, 首先介绍你自己和你申请的职位 7-6 至 7-8 (情商. 7-1); 部分 9, 情商. 9-2, 9-4 和 9-15; 部分 10, 情商. 10-3 和 10-4, 桌子 10-9 and page 10-87; 部分 15, 桌子 15-3.
  • 使用 ICOR 计算螺栓组
  • 使用 AISC 进行钢连接设计 360-16
  • 螺栓 和 焊缝 SkyCiv 连接设计
哈罗德穆纳勒姆, SkyCiv 连接设计产品经理

哈罗德穆纳勒姆
产品经理, 连接设计
10+ 从事钢结构连接设计多年
领英

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