分析设计, 直接法, 塑性载荷, 非线性有限元

A direct route by combining the PWC(plastic work curvature) criterion and the nonlinear FEA technology,was adopted to calculate the plastic internal pressure and the plastic piping loads of an industrial header product, and the calculated results were compared with that of other methods. The comparisons show that the PWC plastic pressure load results of perfect-plastic analysis are very close to the Cloud-Rodabaugh limit pressure result and the ASME limit pressure result; the PWC plastic loads are characterized by reflecting the structural strengthening effect of the material strain-hardening on the header by using the plastic work as the global indicator of plastic collapse mechanism, and avoids the arbitrary of users' experience to select an appropriate deformation parameters for determining the TES(twice elastic slope) plastic loads; the direct route is advantageous of convenient calculation by avoiding the cumbering elastic stress categorization procedure. In summary, the direct method based on the PWC criterion is an effective approach to solving the strength DBA problem of the plate-fin heat exchanger header with complicated structure.    