§13-2杆件变形能计算 轴向拉伸和压缩 V=W=F·△=F 2 EA FI FN 2EA 2EA △l 2EA(x)§13-2 杆件变形能计算 一、轴向拉伸和压缩 V = W F F l l = F l 2 1 EA Fl F 2 1 = EA F l EA F l N 2 2 2 2 = =  = l N x EA x F x V d 2 ( ) ( ) 2 