金属软管轴向静刚度特性试验研究

Experimental research on axial static stiffness characteristics of metal hoses

针对目前对航天管路系统金属软管静刚度特性认识有限的问题,对金属软管开展了轴向刚度试验研究。通过设计轴向刚度试验,考虑了无内压状态和充压0.5 MPa状态下的拉伸、压缩工况,获得了2种不同规格的金属软管试验件的刚度曲线。试验结果表明,软管的轴向刚度表现出了高度非线性,在低刚度阶段两试件的刚度分别为56.82 N/mm和167.13 N/mm,在高刚度阶段两试件的刚度则分别大于3724.62 N/mm和4014.14 N/mm。使用数字图像法,获取了轴向拉伸时网套的编织角变化及外径变化信息,分析了几何非线性和边界非线性因素对软管刚度的影响,提出了基于接触的金属软管非线性力学行为解释。使用有限元仿真方法,对金属软管轴向拉伸过程中的刚度非线性变化进行了复现,验证了基于接触的金属软管非线性力学行为解释的可靠性。为金属软管刚度非线性的进一步分析提供参考。

To address the limited understanding of the static stiffness characteristics of metal hoses in aerospace pipeline systems,axial stiffness tests was carried out on metal hoses.By designing axial stiffness tests,the tensile and compressive conditions under no internal pressure and 0.5 MPa internal pressure were considered,and the stiffness curves of two different specifications of metal hose specimens were obtained.The test results show that the axial stiffness of the hose exhibits high nonlinearity.In the low stiffness stage,the stiffness of the two specimens is 56.82 N/mm and 167.13 N/mm,respectively,while in the high stiffness stage,the stiffness of the two specimens is greater than 3724.62 N/mm and 4014.14 N/mm,respectively.Using digital image method,the braiding angle change and outer diameter change information of the net sleeve during axial tension were obtained,and the effects of geometric nonlinearity and boundary nonlinearity factors on the hose stiffness were analyzed.An explanation of nonlinear mechanical behavior based on contact was proposed for metal hoses.Using finite element simulation method,the nonlinear stiffness change of metal hoses during axial tension was reproduced,and the explanation of reliability of the nonlinear mechanical behavior based on contact for metal hoses was verified.The study provides a reference for further analysis of metal hose stiffness nonlinearity.