复合材料增强管线钢管压力设计新方法

复合材料增强管线钢管(CRLP)是一种具有高承压能力的新型管道,其应用日趋广泛,但相应的管道压力设计方法尚不完善。对现有规范的分析表明,现有压力设计模式已不适合组合型管道。通过以CRLP平均环向应变作为设计的显式失效判据,并区别不同工况下的失效模式,确定相应的安全系数。基于组合薄壁圆筒模型,分别导出了是/否进行预应力处理的压力设计公式。压力设计公式考虑了CRLP几何尺寸、管线钢和复合材料力学性能对设计压力的影响。算例分析表明,对于未经过预应力处理而直接投用的CRLP,主要的失效模式是试压过程中产生过量残余变形;而对于进行过预应力处理的CRLP,主要失效模式转变为工作压力下的蠕变破坏。预应力处理可以一定程度上提高CRLP的设计压力,并有助于充分利用复合材料的承载能力。

A new method for the pressure design of composite reinforced line pipe

Composite reinforced line pipe (CRLP)is a new type of pipeline with high pressure bearing capacity, and is appliced more and more widely, but the corresponding design method of pipeline pressure is not perfect yet. The analysis of existing specifications shows that the existing pressure design model is no longer suitable for combined pipelines. The corresponding safety factor is determined by using CRLP mean hoop strain as the explicit failure criterion for design and distinguishing the failure modes under different working conditions. Based on the combined thin-walled cylinder model, this paper derives pressure design formulas for prestressing treatment (Y/N), respectively. The pressure design formulas consider the influence of CRLP geometry, mechanical properties of pipeline steel and composite on design pressure. The analysis of examples shows that for CRLP directly used without prestressing treatment, the main failure mode is shown as the excessive residual deformation generated during pressure test; and for CRLP after prestressing treatment, the main failure mode is transformed as creep failure under the working pressure. Prestressing treatment can increase the design pressure of CRLP to a certain extent, and help to make full use of the bearing capacity of composite.