Accession Number : AD0696233

Title :   EFFECT OF DIE DEFORMATION ON THE NORMAL STRESS DISTRIBUTION AT THE CONTACT SURFACE DURING THE PRESSING OF THIN BODIES,

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Ivanushkin,P. F. ; Doroshko,V. I.

Report Date : 08 SEP 1969

Pagination or Media Count : 16

Abstract : To determine the effect of the deformation of dies on the normal stress distribution at the contact surface in upsetting thin bodies without widening, lead specimens of various lengths, 7 mm wide, and 4.7, 1.55 and 0.85 mm thick, were pressed with a 50 ton press using rectangular trough-like dies with contact faces of various concavity. The experiments showed that in upsetting thin bodies, the character of the normal stress distribution at the contact surface is determined by the die deformation. In all cases, the normal stresses in the center of the deformed body decreased with increasing concavity of the dies. The effect of the die deformation on the stress distribution became more pronounced as the thickness of the pressed specimens decreased and as the length-to-thickness ratio in the specimens increased. For example, in compression under identical conditions, specimens 240 mm long with a length-to-height ratio of 51, 155 and 283 had a respective deformation of 0.17, 0.09 and 0.08 mm, and the respective central plastically non-deformed portions were 100, 164, and 196 mm, or 0.41, 0.68 and 0.81 of the length of the specimens after deformation. Hence, to increase the precision of the geometric dimensions and to obtain more complete filling of the die groove in the center in die forging of thin parts, the dies should be suitably profiled to offset their deformation.

Descriptors :   (*DIES, DEFORMATION), (*FORGING, STRESSES), FORGE PRESSES, DISTRIBUTION, USSR

Subject Categories : Fabrication Metallurgy
      Machinery and Tools

Distribution Statement : APPROVED FOR PUBLIC RELEASE