Two-step approach of stress classification and primary structure method

A key problem in engineering applications of "design by analysis" approach is how to decompose a total stress field obtained by the finite element ana lysis into different stress categories defined in the ASME Code III and VII I-2. In this paper, we suggest a two-step approach (TSA) of stress classifi cation and a primary structure method (PSM) for identification of primary s tress. Together with the equivalent linearization method (ELM), the stress classification problem is well solved. Some important concepts and ideas di scussed by Lu and Li [Lu, M. W., and Li, J. G., 1986, ASME PVP-Vol. 109, pp . 33-37; Lu, M. W., aid Li, J. G., 1996, ASME PVP-Vol. 340, pp. 357-363] ar e introduced. They are self-limiting stress, multi-possibility of stress de composition, classification of constraints, and primary structures. For ide ntification of peak stress, a modified statement of its characteristic and a "1/4 thickness criterion'' are given. [S0094-9930(00)00201-8].