ANALYSIS ON VARIOUS FACTORS

OF RUPTURE INSTABILITY DURING

CYLINDRICAL CUPS DEEP DRAWING

ZHANG Zhiyuan  ZHAO Shengdun  ZHANG Yong  WANG Ji  YUAN Jianhua

(College of Mechanical Engineering, Xi’an Jiaotong University, Xi’an 710049)

Abstract: The rupture instability and its critical blank-holder force of cylindrical deep drawing in sheet forming process are theoretically and experimentally investigated. The wall of cup drawing is the common tangent region due to the punch, die profile and the clearance of them. The stress distribution of flange, die profile and wall segment are established by Mises-Hill yield function and Tresca criterion. The stress function of the crucial surface occurring rupture instability is constructed. Furthermore, the critical blank-holder force occurs rupture instability is obtained. The effects of various parameters including draw ratio, strain hardening, normal anisotropy, friction coefficient and radial pushing force on rupture instability are showed, analyzed and discussed. During the experiment using 08Al steel sheet as workpieces hydraulic pressure is applied on the blank as blank-holder force and the periphery of the cup flange as radial pushing force. Good agreement is found between the theoretical calculations and the experimental results.

Key words: Sheet forming Deep drawing Instability Critical blank-holder force Rupture

CLC No: TG386.3

西安交通大学博士论文基金(DFXJTU2005-11)和国家自然科学基金(50375117)资助项目. Received 20060508, received in revised form 20061125