1. 斷面性質
斷面: RH 300x300x10x15 (H型)
A = 118.45 cm² | Ix = 19932.8 cm⁴ | Iy = 6752.3 cm⁴
Sx = 1328.8 cm³ | Sy = 450.1 cm³
Zx = 1464.8 cm³ | Zy = 681.8 cm³
rx = 12.97 cm | ry = 7.55 cm
J = 76.50 cm⁴ | Cw = 1371129 cm⁶
Fy = 250 MPa | E = 200,000 MPa
2. 柱軸壓容量 (AISC E3)
Kx = 2.1 | Ky = 2.1 | L = 4.00 m
KxLx/rx = 2.1×4×1000 / (12.97×10) = 64.8
KyLy/ry = 2.1×4×1000 / (7.55×10) = 111.3
控制細長比 KL/r = 111.3 (Y 軸) ≤ 200 → OK
Fe = π²×200000 / 111.3² = 159.5 MPa
4.71√(E/Fy) = 4.71×√(200000/250) = 133.2
111.3 ≤ 133.2 → 非彈性挫屈
Fcr = 129.7 MPa
Pn = Fcr × Ag = 129.7 × 118.45×100 / 1000 = 1536.4 kN
φPn = 0.90 × 1536.4 = 1382.8 kN (1382.79 kN)
3. 梁彎矩容量 (AISC F2/F6)
--- 強軸 X ---
Mp = Fy × Zx = 250 × 1464.8×1000 / 10⁶ = 366.19 kN-m
Lp = 3.758 m | Lr = 13.493 m | Lb = 4.00 m
Lp < Lb ≤ Lr → 非彈性 LTB
控制模式: Inelastic LTB
Mn = 362.87 kN-m
φMnx = 0.90 × 362.87 = 326.58 kN-m (326.58 kN-m)
--- 弱軸 Y ---
Mp_y = min(Fy×Zy, 1.6×Fy×Sy) = 170.44 kN-m
控制模式: Yielding
φMny = 0.90 × 170.44 = 153.39 kN-m (153.39 kN-m)
4. 剪力容量 (AISC G2)
φVn(強軸) = 405.0 kN (405.00 kN)
φVn(弱軸) = 1215.0 kN (1215.00 kN)
5. 載重組合 (LRFD)
| 組合 | Pu (kN) | Mux (kN-m) | Muy (kN-m) | Vuy (kN) | Vux (kN) | B1x | B1y |
|---|
| 1.4D | 28.00 | 0.00 | 0.00 | 0.00 | 0.00 | 1.005 | 1.015 |
| 1.2D + 1.6L | 48.00 | 0.00 | 0.00 | 0.00 | 0.00 | 1.009 | 1.026 |
| 1.2D + 0.5L + 1.6W(X) | 31.50 | 0.00 | 91.12 | 0.00 | 28.80 | 1.006 | 1.017 |
| 1.2D + 0.5L + 1.6W(Y) | 31.50 | 90.11 | 0.00 | 28.80 | 0.00 | 1.006 | 1.017 |
| 1.2D + 0.5L + 1.6(Wx+0.3Wy) ★ | 31.50 | 27.03 | 91.12 | 8.64 | 28.80 | 1.006 | 1.017 |
| 1.2D + 0.5L + 1.6(0.3Wx+Wy) | 31.50 | 90.11 | 27.34 | 28.80 | 8.64 | 1.006 | 1.017 |
| 0.9D + 1.6W(X) | 18.00 | 0.00 | 90.46 | 0.00 | 28.80 | 1.003 | 1.010 |
| 0.9D + 1.6W(Y) | 18.00 | 89.89 | 0.00 | 28.80 | 0.00 | 1.003 | 1.010 |
| 0.9D + 1.6(Wx+0.3Wy) | 18.00 | 26.97 | 90.46 | 8.64 | 28.80 | 1.003 | 1.010 |
| 0.9D + 1.6(0.3Wx+Wy) | 18.00 | 89.89 | 27.14 | 28.80 | 8.64 | 1.003 | 1.010 |
6. 梁柱互制檢核 (AISC H1-1)
控制組合: 1.2D + 0.5L + 1.6(Wx+0.3Wy)
Pr = 31.50 kN | Pc = φPn = 1382.79 kN
Pr/Pc = 0.0228 < 0.2 → 適用 H1-1b
Mrx/Mcx = 27.03 / 326.58 = 0.0828
Mry/Mcy = 91.12 / 153.39 = 0.5940
IR = Pr/(2Pc) + (Mrx/Mcx + Mry/Mcy)
= 0.0114 + (0.0828 + 0.5940)
= 0.6882 ≤ 1.0 → OK
剪力檢核: Vuy/φVn = 0.0213 | Vux/φVnx = 0.0237