6 续) 截面形状 面积A 惯性矩Ⅰ 截面系数W= 形心距离e H BH+bh BH+BHw V12(BH+bh) bh3-bh3 BH3-bh2 BH-bh 12(BH-bh)6 (续) 截面形状 面积A 惯性矩I 截面系数 e I W = 回转半径 A I i = 形心距离e BH + bh 12 3 3 x BH bh I + = H BH bh W 6 3 3 x + = 12( ) 3 3 BH bh BH bh + + 2 H BH - bh 12 3 3 x BH bh I - = H BH bh W 6 3 3 x - = 12( ) 3 3 x BH bh BH bh i - - = 2 H