基于应变强化特性的不锈钢筒体极限载荷分析及其轻量化设计

LIMIT LOAD ANALYSIS AND LIGHT-WEIGHT DESIGN OF STAINLESS STEEL CYLINDER BASED ON STRAIN-HARDENING

将S30408不锈钢的真应力—应变曲线简化为双线性各向同性强化模型,对不锈钢圆筒进行弹塑性分析,得出考虑应变强化特性的圆筒全屈服压力。与采用多线性各向同性强化模型进行非线性有限元计算得到筒体的极限载荷进行比较,两者结果吻合。给出考虑材料应变强化特性的筒体径比计算公式及算图,只要确定了材料的双线性各向同性强化模型参数,即可计算出筒体的径比并确定筒体的厚度。与常规设计法相比,筒体壁厚可减轻28.6%。

By simplifying the true stress-strain curve of S30408 stainless steel as a bilinear isotropic hardening model,an elastic-plastic analysis was carried out theoretically for a stainless steel cylinder.The pressure of the cylinder corresponding to the thoroughly yield across the thickness was obtained with the proposed hardening model.Compared with the limit load obtained by nonlinear finite element analysis based on multi-linear isotropic hardening model,the results agree well.Moreover,formula and charts were worked out for the cylinder diameter ratio with strain-hardening in consideration.Once the material parameters of the bilinear isotropic hardening model are known,the diameter ratio and wall thickness of cylinder can be readily obtained.Compared with conventional design method,the cylinder wall thickness can be reduced 28.6%.