自紧工艺对CFRP气瓶应力水平的影响

文摘利用ABAQUS有限元软件,对铝内胆结构的CFRP气瓶进行了分析,根据其结构建立了模型,采用二维Hashin失效准则对纤维缠绕层进行了渐进失效分析,包含了4种失效模式,纤维及基体的拉伸和压缩失效。研究了不同失效模式的萌生和分布规律。对自紧原理对气瓶的影响进行了研究。分析得出只有当气瓶承载压力大于自紧工艺压力时,内衬PEEQ值才会在自紧工艺后继续发生累积,气瓶自紧力开始失效。

Stress Analyses of CFRP Cylinder Under Autofrettage Process

Stress and damage analyses are performed on a carbon fiber overwrapped aluminum-lined cylinder under internal pressure through finite element method(FEM) by ABAQUS software. The variational thickness and wound angle of the head is reflected in the finite element model in accordance with the actual structure. A progressive damage model considering four failure modes are adopted for the composite, i.e., the fiber tension and compression, the matrix tension and compression. The regularities of the initiation and distribution of autofrettage pressure are analyzed. The effects of the autofrettage pressure on the stress amplitude of the liner are also discussed.It is concluded that when the cylinder carrying pressure is greater than the autofrettage process pressure, the PEEQ value of the liner will continue to accumulate after the autofrettage process, and the autofrettage process of the cylinder starts to fail.