Equal perimeter yield criterion and its specific plastic work rate:Development, validation and application

ZHANG Shun-hu(章顺虎)¹, ZHAO De-wen(赵德文)², CHEN Xiao-dong(陈晓东)³

(1. Shagang School of Iron and Steel, Soochow University, Suzhou 215021, China;
2. State Key Laboratory of Rolling and Automation (Northeastern University), Shenyang 110819, China;
3. School of Chemical and Environmental Engineering, Soochow University, Suzhou 215123, China)

Abstract:In order to overcome the nonlinearity of Mises criterion, a new linear yield criterion with a dodecagon shape of the same perimeter as Mises criterion was derived by means of geometrical analysis. Its specific plastic work rate expressed as a linear function of the yield stress, the maximum and minimum strains was also deduced and compared with that of Mises criterion. The physical meaning of the proposed yield criterion is that yielding of materials begins when the shear yield stress τ_s reaches the magnitude of 0.594σ_s. By introducing the Lode parameter, validation of evolution expressions of the proposed yield criterion with those based on Tresca, Mises and TSS criteria as well as available classical yield experimental results of various metals shows that the present results intersect with Mises results and coincide well with experimental data. Moreover, further application to the limit analysis of circle plate as an example is performed to demonstrate the effectiveness of the proposed yield criterion, and the subsequent comparison of limit loads with the Tresca analytical solutions and Mises numerical results shows that the present results are higher than the Tresca analytical results, and are in good agreement with the Mises numerical results.

Key words:EP yield criterion; specific plastic work rate; circular plate; limit load; analytical solution