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附录 E 柱的计算长度系数

附录 E 柱的计算长度系数

E.0.1 无侧移框架柱的计算长度系数 $ \mu $ 应按表 E.0.1 取值,同时符合下列规定:

1 当横梁与柱铰接时,取横梁线刚度为零。

2 对低层框架柱,当柱与基础铰接时,应取 $ K_{2}=0 $ ,当柱与基础刚接时,应取 $ K_{2}=10 $ ,平板支座可取 $ K_{2}=0.1 $ 。

3 当与柱刚接的横梁所受轴心压力 $ N_{b} $ 较大时,横梁线刚度折减系数 $ \alpha_{N} $ 应按下列公式计算:

横梁远端与柱刚接和横梁远端与柱铰接时:

$$ \alpha_{\mathrm{N}}=1-N_{\mathrm{b}}/N_{\mathrm{E b}} $$

横梁远端嵌固时:

$$ \alpha_{\mathrm{N}}=1-N_{\mathrm{b}}/\left(2N_{\mathrm{E b}}\right) $$

$$ N_{\mathrm{E b}}=\pi^{2}E I_{\mathrm{b}}/l^{2} $$

式中: $ I_{b} $ ——横梁截面惯性矩(mm $ ^{4} $ );

l——横梁长度(mm)。

表 E.0.1 无侧移框架柱的计算长度系数 $ \mu $
Kt00.050.10.20.30.40.512345≥10
01.0000.9900.9810.9640.9490.9350.9220.8750.8200.7910.7730.7600.732
0.050.9900.9810.9710.9550.9400.9260.9140.8670.8140.7840.7660.7540.726
0.10.9810.9710.9620.9460.9310.9180.9060.8600.8070.7780.7600.7480.721
0.20.9640.9550.9460.9300.9160.9030.8910.8460.7950.7670.7490.7370.711
0.30.9490.9400.9310.9160.9020.8890.8780.8340.7840.7560.7390.7260.701
0.40.9350.9260.9180.9030.8890.8770.8660.8230.7740.7470.7300.7190.693
0.50.9220.9140.9060.8910.8780.8660.8550.8130.7650.7380.7210.7100.685
10.8750.8670.8600.8460.8340.8230.8130.7740.7290.7040.6880.6770.654
20.8200.8140.8070.7950.7840.7740.7650.7290.6860.6630.6480.6380.615
30.7910.7840.7780.7670.7560.7470.7380.7040.6630.6400.6250.6160.593
40.7730.7660.7600.7490.7390.7300.7210.6880.6480.6250.6110.6010.580
50.7600.7540.7480.7370.7280.7190.7100.6770.6380.6160.6010.5920.570
≥100.7320.7260.7210.7110.7010.6930.6850.6540.6150.5930.5800.5700.549

注:1 表中的计算长度系数 $ \mu $ 值系按下式算得:

$$ \left[\left(\frac{\pi}{\mu}\right)^{2}+2(K_{1}+K_{2})-4K_{1}K_{2}\right]\frac{\pi}{\mu}\cdot\sin\frac{\pi}{\mu}-2\left[(K_{1}+K_{2})\left(\frac{\pi}{\mu}\right)^{2}+4K_{1}K_{2}\right]\cos\frac{\pi}{\mu}+8K_{1}K_{2}=0 $$

式中, $ K_{1}, K_{2} $ 分别为相交子柱上端、柱下端的横梁线刚度之和与柱线刚度之和的比值。当梁远端为铰接时,应将横梁线刚度乘以1.5;当横梁远端为嵌固时,则将横梁线刚度乘以2。

E.0.2 有侧移框架柱的计算长度系数 $ \mu $ 应按表 E.0.2 取值,同时符合下列规定:

1 当横梁与柱铰接时,取横梁线刚度为零。

2 对低层框架柱,当柱与基础铰接时,应取 $ K_{2}=0 $ ,当柱与基础刚接时,应取 $ K_{2}=10 $ ,平板支座可取 $ K_{2}=0.1 $ 。

3 当与柱刚接的横梁所受轴心压力 $ N_{b} $ 较大时,横梁线刚度折减系数 $ \alpha_{N} $ 应按下列公式计算:

横梁远端与柱刚接时:

$$ \alpha_{\mathrm{N}}=1-N_{\mathrm{b}}/\left(4N_{\mathrm{E b}}\right) $$

横梁远端与柱铰接时:

$$ \alpha_{\mathrm{N}}=1-N_{\mathrm{b}}/N_{\mathrm{E b}} $$

横梁远端嵌固时:

$$ \alpha_{\mathrm{N}}=1-N_{\mathrm{b}}/\left(2N_{\mathrm{E b}}\right) $$

表 E.0.2 有侧移框架柱的计算长度系数 $ \mu $
K1K200.050.10.20.30.40.512345≥10
06.024.453.423.012.782.642.332.172.112.082.072.03
0.056.024.163.472.862.582.422.312.071.941.901.871.861.83
0.14.463.473.012.562.332.202.111.901.791.751.731.721.70
0.23.422.862.362.232.051.941.871.701.601.571.551.541.52
0.33.012.582.332.051.901.801.741.581.491.461.451.441.42
0.42.782.422.201.941.801.711.651.501.421.391.371.371.35
0.52.642.312.111.871.741.651.591.451.371.341.321.321.30
12.332.071.901.701.581.501.451.321.241.211.201.191.17
22.171.941.791.601.491.421.371.241.161.141.121.121.10
32.111.901.751.571.461.391.341.211.141.111.101.091.07
42.081.871.731.551.451.371.321.201.121.101.081.081.06
52.071.861.721.541.441.371.321.191.121.091.081.071.05
≥102.031.831.701.521.421.351.301.171.101.071.061.051.03
注:1 表中的计算长度系数 $ \mu $ 值系按下式算得:

$$ \left[\frac{36K_{1}K_{2}-\left(\frac{\pi}{\mu}\right)^{2}}{}\right]\sin\frac{\pi}{\mu}+6(K_{1}+K_{2})\frac{\pi}{\mu}\cdot\cos\frac{\pi}{\mu}=0 $$

式中, $ K_{1}, K_{2} $ 分别为相交于柱上端、柱下端的横梁线刚度之和与柱线刚度之和的比值。当横梁远端为铰接时,应将横梁线刚度乘以0.5;当横梁远端为嵌固时,则应乘以2/3。

E.0.3 柱上端为自由的单阶柱下段的计算长度系数 $ \mu_{2} $ 应按表 E.0.3 取值。

表 E.0.3 柱上端为自由的单阶柱下段的计算长度系数 $ \mu_{2} $
简图K10.060.080.100.120.140.160.180.200.220.240.260.280.30.40.50.60.70.8
0.22.002.012.012.012.012.012.012.022.022.022.022.022.022.032.042.052.062.07
0.32.012.022.022.022.032.032.032.042.042.052.052.052.062.082.102.122.132.15
0.42.022.032.042.042.052.062.072.072.082.092.092.102.112.142.182.212.252.28
0.52.042.052.062.072.092.102.112.122.132.152.162.172.182.242.292.352.402.45
K1=I1/I2·H2/H10.62.062.082.102.122.142.162.182.192.212.232.252.262.282.362.442.522.592.66
0.72.102.132.162.182.212.242.262.292.312.342.362.382.412.522.622.722.812.90
0.82.152.202.242.272.312.342.382.412.442.472.502.532.562.702.822.943.063.16
0.92.242.292.352.392.442.482.522.562.602.632.672.712.742.903.053.193.323.44
1.02.362.432.482.542.592.642.692.732.772.822.862.902.943.123.293.453.593.74
η1=H1/H2√(N1/N2·I2/I1)1.22.692.762.832.892.953.013.073.123.173.223.273.323.373.593.803.994.174.34
1.43.073.143.223.293.363.423.483.553.613.663.723.783.834.094.334.564.774.97
1.63.473.553.633.713.783.853.923.994.074.124.184.254.314.614.885.145.385.62
N1——上段柱的轴心力;1.83.883.974.054.134.214.294.374.444.524.594.664.734.805.135.445.736.006.26
N2——下段柱的轴心力2.04.294.394.484.574.654.744.824.904.995.075.145.225.305.666.006.326.636.92
2.24.714.814.915.005.105.195.285.375.465.545.635.715.806.196.576.927.267.58
2.45.135.245.345.445.545.645.745.845.936.036.126.216.306.737.147.527.898.24
2.65.555.665.775.885.996.106.206.316.416.516.616.716.807.277.718.138.528.90
2.85.976.096.216.336.446.556.676.786.896.997.107.217.317.818.288.739.169.57
3.06.396.526.646.776.897.017.137.257.377.487.597.717.828.358.869.349.8010.24

注:表中的计算长度系数 $ \mu_{2} $ 值系按下式计算得出:

$$ \eta_{1}K_{1}\cdot\operatorname{tg}\frac{\pi}{\mu_{2}}\cdot\operatorname{tg}\frac{\pi\eta_{1}}{\mu_{2}}-1=0 $$

E.0.4 柱上端可移动但不转动的单阶柱下段的计算长度系数 $ \mu_{2} $ 应按表 E.0.4 取值。

表 E.0.4 柱上端可移动但不转动的单阶柱下段的计算长度系数 $ \mu_{2} $
简图K1η10.060.080.100.120.140.160.180.200.220.240.260.280.30.40.50.60.70.8
0.21.961.941.931.911.901.891.881.861.851.841.831.821.811.761.721.681.651.62
0.31.961.941.931.921.911.891.881.871.861.851.841.831.821.771.731.701.661.63
0.41.961.951.941.921.911.901.891.881.871.861.851.841.831.791.751.721.681.66
0.51.961.951.941.931.921.911.901.891.881.871.861.851.851.811.771.741.711.69
0.61.971.961.951.941.931.921.911.901.901.891.881.871.871.831.801.781.751.73
0.71.971.971.961.951.941.941.931.921.921.911.901.901.891.861.841.821.801.78
0.81.981.981.971.961.961.951.951.941.941.931.931.931.921.901.881.871.861.84
0.91.991.991.981.981.981.971.971.971.971.961.961.961.961.951.941.931.921.92
1.02.002.002.002.002.002.002.002.002.002.002.002.002.002.002.002.002.002.00
K1=I1/I2·H2/H11.22.032.042.042.052.062.072.072.082.082.092.102.102.112.132.152.172.182.20
1.42.072.092.112.122.142.162.172.182.202.212.222.232.242.292.332.372.402.42
η1=H1/H2√N1/N2·I2/I11.62.132.162.192.222.252.272.302.322.342.362.372.392.412.482.542.592.632.67
1.82.222.272.312.352.392.422.452.482.502.532.552.572.592.692.762.832.882.93
N1——上段柱的轴心力;2.02.352.412.462.502.552.592.622.662.692.722.752.772.802.913.003.083.143.20
N2——下段柱的轴心力2.22.512.572.632.682.732.772.812.852.892.922.952.983.013.143.253.333.413.47
2.42.682.752.812.872.922.973.013.053.093.133.173.203.243.383.503.593.683.75
2.62.872.943.003.063.123.173.223.273.313.353.393.433.463.623.753.863.954.03
2.83.063.143.203.273.333.383.433.483.533.583.623.663.703.874.014.134.234.32
3.03.263.343.413.473.543.603.653.703.753.803.853.893.934.124.274.404.514.61

注:表中的计算长度系数 $ \mu_{2} $ 值系按下式计算得出:

$$ \mathrm{tg}\frac{\pi\eta_{1}}{\mu_{2}}+\eta_{1}K_{1}\cdot\mathrm{tg}\frac{\pi}{\mu_{2}}=0 $$

柱上端为自由的双阶柱下段的计算长度系数 $ \mu_{3} $ 应按下列公式计算,也可按表 E.0.5 取值。

表 E.0.5 柱上端为自由的双阶柱下段的计算长度系数 $ \mu_{3} $
简图K1
简图K1

注:表中的计算长度系数 $ \mu_{s} $ 值系按下式算得:

$$ \frac{\eta_{1}K_{1}}{\eta_{2}K_{2}}\cdot\frac{\pi\eta_{1}}{\mu_{1}}\cdot\frac{\pi\eta_{2}}{\mu_{2}}+\frac{\pi\eta_{1}}{\eta_{1}}K_{1}\cdot\frac{\pi\eta_{1}}{\mu_{1}}\cdot\frac{\pi\eta_{2}}{\mu_{2}}+\frac{\pi\eta_{1}}{\eta_{2}}K_{2}\cdot\frac{\pi\eta_{2}}{\mu_{2}}\cdot\frac{\pi\eta_{1}}{\mu_{1}}-1=0 $$

表 E.0.6 柱顶可移动但不转动的双阶柱下段的计算长度系数 $ \mu_{3} $
简图K1
简图R1

注:表中的计算长度系数 $ \mu_{r} $ 值系按下式算得:

$$ \frac{\pi_{1}K_{1}}{\pi_{2}K_{2}}\cdot\operatorname{ctg}\frac{\pi\eta_{1}}{\mu_{3}}\cdot\operatorname{ctg}\frac{\pi\eta_{2}}{\mu_{3}}+\frac{\pi_{1}K_{1}}{(\pi_{2}K_{2})^{2}}\cdot\operatorname{ctg}\frac{\pi\eta_{2}}{\mu_{3}}\cdot\operatorname{ctg}\frac{\pi\eta_{3}}{\mu_{3}}+\frac{1}{\pi_{2}K_{2}}\cdot\operatorname{ctg}\frac{\pi\eta_{2}}{\mu_{3}}\cdot\operatorname{ctg}\frac{\pi\eta_{3}}{\mu_{3}}-1=0 $$