フェノールレジン積層板のせん断加工 (第5報)
せん断機構の力学的解析
1964 年 30 巻 357 号 p. 785-793
詳細
1964 年 30 巻 357 号 p. 785-793
Stress distributions in the rectangular region enclosed with parts compressed by punch and die were analysed for the process of elastic deformation in shearing, employing the shearing model which was induced from the previous reports. Assuming that the stress distributions had no change until the early stage of appearance of first micro-cracks, and using failure condition for plastic anisotropic body, angles of first micro-cracks (α) and reduced shearing forces (kc) at the moment of appearance of first micro-cracks were calculated and they were compared with each observed values. Thus, it was confirmed that the shearing model adopted here was suitable for shearing mechanism.
The results obtained are as follows :
(1) The values of α increase and the values of kc, decrease as the rectangular region sheared by tool becomes smaller, and applied forces concentrate at the cutting edges.
(2) The values of α and kc, decrease as the side force increase.
(3) The values of α increase and the values of kc decrease in the case where normal tensile stress act on the vertical sections of the sheared part.
(4) Distributions of stresses and α along the center line of the clearance between punch and die have the transition points near the surface layer of the sheared part, in which points values of α are minimum and first micro-cracks begin to appear.
