基于薄壁容器理论及卸载后容器内衬残余应变为零的假设,提出了一种含金属内衬的复合材料缠绕薄壁容器自紧设计的工程方法,在自紧压力预测中可分别考虑金属内衬的双线性随动和等向强化特征。通过与有限元分析结果比较,证明了本文中提出的自紧设计方法的简便性和有效性。以一典型容器为例,研究了在自紧工艺后内衬的残余应变场和工作压力时应力场分布,证明了采用本文中提出的自紧设计可明显提高容器的承载能力。
Based on thin-wall vessel theory and null-unloading-residual-strain assumption,a simplified engineering formula for autofrettage pressure of composite overwrapped pressure vessels(COPV) was deduced,in which the effects of bilinear isotropic and kinetic hardening behavior for metal inner were considered respectively.The validity of the engineering formula was verified through comparing with FEM.As an example,the residual strain field after autofrettage technique and corresponding stress field under the service loading case for a typical COPV were studied.The results indicate that the load capacity of COPV significantly increases by means of the autofrettage technique provide in this paper.