断面二次半径
”断面二次半径”とは座屈の起きやすさを表す断面性能の値で、物体の断面を変えると”断面二次半径”の値も変化し、この値が大きければ大きいほど部材は座屈に強くなります。
また”断面二次半径”は通称SI単位と呼ばれる国際単位では"m"で表され、構造計算で座屈強度を計算する場合などに用いられます。
丸形鋼管の”断面二次半径(i)”は"断面二次モーメント(I)"と密接な関係があり、以下の計算式で有効数字3桁でもとめられます。
丸形鋼管の”断面二次半径(i)” = √( I / A )
I:丸形鋼管の”断面二次モーメント”
A:断面積
角形鋼管の””断面二次半径”は角の丸みも考慮されます。また長方形の角形鋼管の場合は向きにより”断面二次半径”の値が変わります。各サイズの角形鋼管の”断面二次半径”は、以下の表を参考にしてください。
角形鋼管の寸法及び単位質量(正方形)
辺の長さ A×B |
厚さ t |
単位質量 W |
断面積 A |
断面二次モーメント I |
断面係数 Z |
断面二次半径 i |
mm | mm | kg/m | cm2 | cm4 | cm3 | cm |
40x40 | 1.6 | 1.88 | 2.392 | 5.79 | 2.90 | 1.56 |
2.3 | 2.62 | 3.332 | 7.73 | 3.86 | 1.52 | |
50×50 | 1.6 | 2.38 | 3.032 | 11.7 | 4.68 | 1.96 |
2.3 | 3.34 | 4.252 | 15.9 | 6.34 | 1.93 | |
3.2 | 4.50 | 5.727 | 20.4 | 8.16 | 1.89 | |
60×60 | 1.6 | 2.88 | 3.672 | 20.7 | 6.89 | 2.37 |
2.3 | 4.06 | 5.172 | 28.3 | 9.44 | 2.34 | |
3.2 | 5.50 | 7.007 | 36.9 | 12.30 | 2.30 | |
75×75 | 1.6 | 3.64 | 4.632 | 41.3 | 11.00 | 2.99 |
2.3 | 5.14 | 6.552 | 57.1 | 15.20 | 2.95 | |
3.2 | 7.01 | 8.927 | 75.5 | 20.10 | 2.91 | |
4.5 | 9.55 | 12.17 | 98.6 | 26.3 | 2.85 | |
80×80 | 2.3 | 5.50 | 7.012 | 69.9 | 17.5 | 3.2 |
3.2 | 7.51 | 9.567 | 92.7 | 23.2 | 3.1 | |
4.5 | 10.3 | 13.07 | 122 | 30.4 | 3.05 | |
90×90 | 2.3 | 6.23 | 7.932 | 101 | 22.4 | 3.6 |
3.2 | 8.51 | 10.85 | 135 | 29.9 | 3.5 | |
100×100 | 2.3 | 6.95 | 8.852 | 140 | 27.9 | 4.0 |
3.2 | 9.52 | 12.13 | 187 | 37.5 | 3.9 | |
4.0 | 11.7 | 14.95 | 226 | 45.30 | 3.89 | |
4.5 | 13.1 | 16.67 | 249 | 49.90 | 3.9 | |
6.0 | 17.0 | 21.63 | 311 | 62.3 | 3.8 | |
9.0 | 24.1 | 30.67 | 408 | 81.6 | 3.7 | |
12.0 | 30.2 | 38.53 | 471 | 94.3 | 3.5 | |
125×125 | 3.2 | 12.0 | 15.330 | 376.0 | 60.1 | 5.0 |
4.5 | 16.6 | 21.170 | 506.0 | 80.9 | 4.9 | |
5.0 | 18.3 | 23.360 | 553 | 88.4 | 4.9 | |
6.0 | 21.7 | 27.63 | 641 | 103.0 | 4.8 | |
9.0 | 31.1 | 39.670 | 865.0 | 138.0 | 4.7 | |
12.0 | 39.7 | 50.530 | 1030 | 165.0 | 4.5 | |
150×150 | 4.5 | 20.1 | 25.670 | 896 | 120.0 | 5.9 |
5.0 | 22.3 | 28.36 | 982 | 131 | 5.9 | |
6.0 | 26.4 | 33.63 | 1150 | 153 | 5.8 | |
9.0 | 38.2 | 48.67 | 1580 | 210 | 5.7 | |
175×175 | 4.5 | 23.7 | 30.17 | 1450 | 166 | 6.9 |
5.0 | 26.2 | 33.36 | 1590 | 182 | 6.9 | |
6.0 | 31.1 | 39.63 | 1860 | 213 | 6.9 | |
200×200 | 4.5 | 27.2 | 34.67 | 2190 | 219 | 8.0 |
6.0 | 35.8 | 45.63 | 2830 | 283 | 7.9 | |
8.0 | 46.9 | 59.79 | 3620 | 362 | 7.8 | |
9.0 | 52.3 | 66.67 | 3990 | 399 | 7.7 | |
12.0 | 67.9 | 86.53 | 4980 | 498 | 8 | |
250×250 | 5.0 | 38.0 | 48.36 | 4810 | 384 | 10 |
6.0 | 45.2 | 57.63 | 5670 | 454 | 10 | |
8.0 | 59.5 | 75.79 | 7320 | 585 | 10 | |
9.0 | 66.5 | 84.67 | 8090 | 647 | 10 | |
12.0 | 86.8 | 110.50 | 10300 | 820 | 10 | |
300×300 | 4.5 | 41.3 | 52.67 | 7630 | 508 | 12 |
6.0 | 54.7 | 69.63 | 9960 | 664 | 12 | |
9.0 | 80.6 | 102.70 | 14300 | 956 | 12 | |
12.0 | 106 | 134.50 | 18300 | 1220 | 12 | |
350×350 | 9.0 | 94.7 | 120.70 | 23200 | 1320 | 14 |
12.0 | 124 | 158.50 | 29800 | 1700 | 14 |
角形鋼管の寸法及び単位質量(長方形)
辺の長さ | 厚さ | 単位質量 | 断面積 | 断面二次モーメント | 断面係数 | 断面二次半径 | |||
A x B | t | W | A | Ix | Iy | Zx | Zy | ix | iy |
mm | mm | kg/m | cm2 | cm4 | cm3 | cm | |||
50 × 20 | 1.6 | 1.63 | 2.072 | 6.08 | 1.42 | 2.43 | 1.42 | 1.71 | 0.829 |
2.3 | 2.25 | 2.872 | 8.00 | 1.83 | 3.20 | 1.83 | 1.67 | 0.798 | |
50 × 30 | 1.6 | 1.88 | 2.392 | 7.96 | 3.60 | 3.18 | 2.40 | 1.82 | 1.23 |
2.3 | 2.62 | 3.332 | 10.6 | 4.76 | 4.25 | 3.17 | 1.79 | 1.20 | |
60 × 30 | 1.6 | 2.13 | 2.712 | 12.5 | 4.25 | 4.16 | 2.83 | 2.15 | 1.25 |
2.3 | 2.98 | 3.792 | 16.8 | 5.65 | 5.61 | 3.76 | 2.11 | 1.22 | |
3.2 | 3.99 | 5.087 | 21.4 | 7.08 | 7.15 | 4.72 | 2.05 | 1.18 | |
75 × 20 | 1.6 | 2.25 | 2.872 | 17.6 | 2.10 | 4.69 | 2.10 | 2.47 | 0.855 |
2.3 | 3.16 | 4.022 | 23.7 | 2.73 | 6.31 | 2.73 | 2.43 | 0.824 | |
75 × 45 | 1.6 | 2.88 | 3.672 | 28.4 | 12.9 | 7.56 | 5.75 | 2.78 | 1.88 |
2.3 | 4.06 | 5.172 | 38.9 | 17.6 | 10.4 | 7.82 | 2.74 | 1.84 | |
3.2 | 5.50 | 7.007 | 50.8 | 22.8 | 13.5 | 10.1 | 2.69 | 1.80 | |
80 × 40 | 1.6 | 2.88 | 3.672 | 30.7 | 10.5 | 7.68 | 5.26 | 2.89 | 1.69 |
2.3 | 4.06 | 5.172 | 42.1 | 14.3 | 10.5 | 7.14 | 2.85 | 1.66 | |
3.2 | 5.50 | 7.007 | 54.9 | 18.4 | 13.7 | 9.21 | 2.80 | 1.62 | |
90 × 45 | 2.3 | 4.60 | 5.862 | 61.0 | 20.8 | 13.6 | 9.22 | 3.23 | 1.88 |
3.2 | 6.25 | 7.967 | 80.2 | 27.0 | 17.8 | 12.0 | 3.17 | 1.84 | |
100 × 20 | 1.6 | 2.88 | 3.672 | 38.1 | 2.78 | 7.61 | 2.78 | 3.22 | 0.870 |
2.3 | 4.06 | 5.172 | 51.9 | 3.64 | 10.4 | 3.64 | 3.17 | 0.839 | |
100 × 40 | 1.6 | 3.38 | 4.312 | 53.5 | 12.9 | 10.7 | 6.44 | 3.52 | 1.73 |
2.3 | 4.78 | 6.092 | 73.9 | 17.5 | 14.8 | 8.77 | 3.48 | 1.70 | |
4.2 | 8.32 | 10.60 | 120 | 28.5 | 24.0 | 13.8 | 3.36 | 1.61 | |
100 × 50 | 1.6 | 3.64 | 4.632 | 61.3 | 21.1 | 12.3 | 8.43 | 3.64 | 2.13 |
2.3 | 5.14 | 6.552 | 8 4.8 |
29.0 | 17.0 | 11.6 | 3.60 | 2.10 | |
3.2 | 7.01 | 8.927 | 112 | 38.0 | 22.5 | 15.2 | 3.55 | 2.06 | |
4.5 | 9.55 | 12.17 | 147 | 48.9 | 29.3 | 19.5 | 3.47 | 2.00 | |
125 × 40 | 1.6 | 4.01 | 5.112 | 94.4 | 15.8 | 15.1 | 7.91 | 4.30 | 1.76 |
2.3 | 5.69 | 7.242 | 131 | 21.6 | 20.9 | 10.8 | 4.25 | 1.73 | |
125 × 75 | 2.3 | 6.95 | 8.852 | 192 | 87.5 | 30.6 | 23.3 | 4.65 | 3.14 |
3.2 | 9.52 | 12.13 | 257 | 117 | 41.1 | 31.1 | 4.60 | 3.10 | |
4.0 | 11.7 | 14.95 | 311 | 141 | 49.7 | 37.5 | 4.56 | 3.07 | |
4.5 | 13.1 | 16.67 | 342 | 155 | 54.8 | 41.2 | 4.53 | 3.04 | |
6.0 | 17.0 | 21.63 | 428 | 192 | 68.5 | 51.1 | 4.45 | 2.98 | |
150 × 75 | 3.2 | 10.8 | 13.73 | 402 | 137 | 53.6 | 36.6 | 5.41 | 3.16 |
150 × 80 | 4.5 | 15.2 | 19.37 | 563 | 211 | 75.0 | 52.9 | 5.39 | 3.30 |
5.0 | 16.8 | 21.36 | 614 | 230 | 81.9 | 57.5 | 5.36 | 3.28 | |
6.0 | 19.8 | 25.23 | 710 | 264 | 94.7 | 66.1 | 5.31 | 3.24 | |
150 × 100 | 3.2 | 12.0 | 15.33 | 488 | 262 | 65.1 | 52.5 | 5.64 | 4.14 |
4.5 | 16.6 | 21.17 | 658 | 352 | 87.7 | 70.4 | 5.58 | 4.08 | |
6.0 | 21.7 | 27.63 | 835 | 444 | 111 | 88.8 | 5.50 | 4.01 | |
9.0 | 31.1 | 39.67 | 1130 | 595 | 151 | 119 | 5.33 | 3.87 | |
200 × 100 | 4.5 | 20.1 | 25.67 | 1330 | 455 | 133 | 90.9 | 7.20 | 4.21 |
6.0 | 26.4 | 33.63 | 1700 | 577 | 170 | 115 | 7.12 | 4.14 | |
9.0 | 38.2 | 48.67 | 2350 | 782 | 235 | 156 | 6.94 | 4.01 | |
200 × 150 | 4.5 | 23.7 | 30.17 | 1760 | 1130 | 176 | 151 | 7.64 | 6.13 |
6.0 | 31.1 | 39.63 | 2270 | 1460 | 227 | 194 | 7.56 | 6.06 | |
9.0 | 45.3 | 57.67 | 3170 | 2020 | 317 | 270 | 7.41 | 5.93 | |
250 × 150 | 6.0 | 35.8 | 45.63 | 3890 | 1770 | 311 | 236 | 9.23 | 6.23 |
9.0 | 52.3 | 66.67 | 5480 | 2470 | 438 | 330 | 9.06 | 6.09 | |
12.0 | 67.9 | 86.53 | 6850 | 3070 | 548 | 409 | 8.90 | 5.95 | |
300 × 200 | 6.0 | 45.2 | 57.63 | 7370 | 3960 | 491 | 396 | 11.3 | 8.29 |
9.0 | 66.5 | 84.67 | 10500 | 5630 | 702 | 563 | 11.2 | 8.16 | |
12.0 | 86.8 | 110.5 | 13400 | 7110 | 890 | 711 | 11.0 | 8.02 | |
350 × 150 | 6.0 | 45.2 | 57.63 | 8910 | 2390 | 509 | 319 | 12.4 | 6.44 |
9.0 | 66.5 | 84.67 | 12700 | 3370 | 726 | 449 | 12.3 | 6.31 | |
12.0 | 86.8 | 110.5 | 16100 | 4210 | 921 | 562 | 12.1 | 6.17 | |
400 × 200 | 6.0 | 54.7 | 69.63 | 14800
|
5090 | 739 | 509 | 14.6 | 8.55 |
9.0 | 80.6 | 102.7 | 21300 | 7270 | 1070 | 727 | 14.4 | 8.42 | |
12.0 | 106 | 134.5 | 27300 | 9230 | 1360 | 923 | 14.2 | 8.23 |