超薄钛内衬复合材料高压气瓶力学特性分析

以卫星用超薄钛内衬T1000碳纤维增强复合材料高压气瓶为研究对象,基于各向同性材料弹塑性理论及复合材料层合板理论,建立三维有限元分析模型。通过对比分析金属内衬和复合材料层在不同内压下的位移、应力和应变分布规律,得到了这种气瓶在各承压工况下的力学特性,最后通过压力试验结果验证了有限元模型的准确性。研究结果表明:当内压超过气瓶的工作压力时,复合材料气瓶主要发生轴向变形,且内衬既有弹性变形又有塑性变形,复合材料层始终处于弹性变形。此外,气瓶爆破失效薄弱点在筒体与封头的过渡区域,在不均匀应变的作用下易沿环向发生撕裂而爆破。本文的研究成果可为超薄内衬复合材料高压气瓶的设计、试验等提供参考依据。

Analysis on Mechanical Properties of Ultra-thin Titanium-Lined Composite High-Pressure Vessels

A T1000 carbon fiber-reinforced composite high-pressure vessel with an ultra-thin titanium liner for satellite applications is studied. A three-dimensional finite element (FE) model is established based on the elastic-plastic theory for isotropic materials and the laminated plate theory for composite materials. The displacement, the strain distribution, and the stress distribution of the metal liner and the laminated composite under different internal pressure conditions are compared and analyzed, and thus the mechanical properties of this kind of vessels under different internal pressure conditions are obtained. The validity of the FE model is verified by the pressure test results. It is shown that, when the internal pressure exceeds the operating pressure of the vessel, the composite vessel mainly deforms along the axial direction, the ultra-thin titanium liner has both elastic deformation and plastic deformation, while the laminated composite only has elastic deformation. In addition, the weak point for vessel burst failure is located in the transitional region between the cylinder and the head of the vessel. Under the action of non-uniform strain, the vessel is easy to tear and burst along the hoop direction. The research results of the present paper can provide references for the design and test of ultra-thin lined composite high-pressure vessels.