Dual assessment criterion and its programmed application of collapse failure of pressure vessels

Design standards of preventing “plastic collapse” and “excessive overall plastic deformation” for pressure vessels are given in the ASME BPVC Section VIII Division 2 and EN 13445, respectively. These two aspects are both taken into account in the dual criterion, which could avoid the two failure modes at the same time. And the dual criterion has been adopted as Appendix B in the forthcoming revised version of Chinese JB-4732-1995 “Steel Pressure Vessel-Analysis and Design Code”. In order to realize engineering application for the dual criterion, two feasible schemes to determine quasi-limit load is proposed in this paper, and the APDL (ANSYS Parametric Design Language) is used for the programming. A dual assessment criterion module is embedded in ANSYS finite element software. On this basis, a design example of the dual assessment criterion program is analyzed. The ANSYS dual criterion assessment module is used to conduct the assessment of different material models, different quasi-limit load determination methods and different levels of design loads. The results show that the dual assessment criterion module is effective for engineering practice.