常用截面图形的几何性质
A=bh
= 0
= 0 = 0
符号：A = 面积；= 至形心C的距离；I
x,I
y
= 对轴的惯性矩；I x,I y = 对轴的惯
J = I
x
+ I y = 极惯性矩；I BB = 对B-B轴的惯性矩
