深冷高压储氢气瓶复合材料层低温力学性能分析与优化

Analysis and optimization of cryogenic mechanical properties of composite layer of cryo-compressed hydrogen storage vessel

为提高深冷、高压双重极端工况作用下复合材料层的低温力学性能,根据层合板理论构建了深冷高压储氢气瓶复合材料层力学分析模型.通过计算热力耦合作用下多层缠绕结构的各向应力,研究横向弹性模量和纤维缠绕角度对复合材料层低温力学性能的影响.以容积140 L、压力35 MPa的气瓶为研究对象,结果表明,当横向弹性模量由14 GPa降低到5 GPa,复合材料横向应力减小68.37%,降低了基体受力失效风险;在0~50°范围内,复合材料横向应力随着螺旋缠绕角度的增加而减小,螺旋缠绕层可承载环向应力由68.18 MPa提高到424.13 MPa.横向弹性模量的降低和螺旋缠绕角度的增加使得各缠绕层的Tsai-Wu失效准则系数下降,有利于提高复合材料层的低温力学性能,减少碳纤维缠绕层数.

In order to improve the cryogenic mechanical properties of the composite layer under the double extreme working conditions of cryogenic temperature and high pressure, the mechanical analysis model of the composite layer of cryo-compressed hydrogen(CcH2) storage vessel was established according to the laminated plate theory. The influence of the transverse elastic modulus and fiber winding angle on the cryogenic mechanical properties of the composite layer was studied by calculating the isotropic stress of the multi-ply winding structure under the thermal mechanical coupling effect. Then, a storage vessel with volume 140 L and pressure 35 MPa was taken as the research object. The results show that when the transverse elastic modulus decreases from 14 GPa to 5 GPa, the transverse stress of the composites decreases by 68.37%, reducing the risk of matrix failure under stress. In the range of 0 to 50°, the transverse stress of the composites decreases with the increase of the helical winding angle, and the hoop stress that can be carried by the helical winding layer increases from 68.18 MPa to 424.13 MPa. The decrease of transverse elastic modulus and the increase of helical winding angle make the Tsai-Wu failure criterion coefficient of each winding ply decrease, which is conducive to improving the cryogenic mechanical properties of the composite layer and reducing the number of carbon fiber winding plies.