弯曲了的钣料,像图1那样,在弯曲部分的里边,材料受到了压缩作用,外边受到了拉伸作用。我们可以想像:在材料中间,有一层既没有受到压缩、又没有受到拉伸,这一层我们叫它做中性层。它的位置可以由材料弯曲半径 R 表示(图2)。 The curved sheet material, like the one in Figure 1, has a compression effect on the inside of the bend and a stretch on the outside. We can imagine that in the middle of the material, there is a layer that is neither compressed nor stretched. We call it a neutral layer. Its position can be expressed by the material bending radius R (Figure 2).