材料弯曲时,在弯曲外表面产生的拉伸变形一旦超过材料固有的拉伸变形极限时,有可能发生弯曲裂纹。为预防之,可以采用减少外表面拉伸变形或提高材料延性的办法,具体措施如下: 1.减少外表面拉伸变形由于外表面所产生的拉伸变形与t/r成比例,所以在产品设计上,可以通过加大弯曲半径r或减小板厚t,来减少外表面的拉伸变形。如果二者都无法实现,则可按图1所示,在弯曲部分的内侧开一缺口,使弯曲部分的板厚尽可能变薄。 2.对外表部分施加压缩应力所谓从外部加力,就是无论采用什么方法,都 When the material is bent, flexural cracks may occur when the tensile deformation at the curved outer surface exceeds the intrinsic tensile deformation limit of the material. To prevent this, you can reduce the outer surface of the tensile deformation or increase the material ductility approach, the specific measures are as follows: 1. Reduce the deformation of the outer surface Tensile deformation due to the outer surface is proportional to t / r, so the product Design, you can increase the bending radius r or reduce the thickness t, to reduce the outer surface of the tensile deformation. If neither of them is possible, as shown in Fig. 1, a notch may be formed on the inner side of the bent portion so that the thickness of the bent portion becomes as thin as possible. 2. To apply compressive stress on the outer part of the so-called force from the outside, that is, no matter what method is used