多层包扎高压容器承载能力分析

Analysis of Load-bearing Capacity of Multi-layer Wrapped High Pressure Vessels

在多层包扎式高压容器制造过程中,理想情况下层板的包扎会使筒体产生预应力,但如果制造精度不够,容器层板间可能出现间隙,就无法保证预应力的充分施加。理论推导得到了有无预应力两种情况下受压力作用时多层包扎高压容器筒体中应力的计算表达式以及极限载荷计算式,并进行了数值模拟验证。研究发现,理论和数值模拟结果较为吻合,预应力的施加显著降低内筒体的工作应力水平,并且能有效改善弹性状态下筒体的应力状态,提高筒体弹性承载能力。然而,在全屈服状态,预应力没有提高容器的极限承载能力,容器极限承载能力仅取决于内筒体和层板的厚度与材料性能。另外,理论分析和数值模拟还表明层间间隙的存在也不会影响容器筒体的极限承载能力。

In ideal manufacture of multilayer wrapped high pressure vessels,pre-stresses would be induced at the cylinders.But if the manufacture is not so accurate,interlayer clearances would exist and the pre-stresses cannot be guaranteed.In this paper,expressions for the stresses in multilayer wrapped high pressure vessels under pressure loading with or without pre-stresses were derived.Numerical simulations were conducted for verification.It is found that the analytic results are in good agreement with the numerical simulations and both indicate that application of pre-stresses can effectively improve the elastic stress distribution at the cylinder and increase the pressure-bearing capacity of the cylinder in the elastic stage.In the whole yielding stage,however,the limit-pressure of the cylinder only depends the thickness and materials of the inner cylinder and layers and is not affected by the pre-stresses.In addition,both analytic and numerical results also found the limit-pressure of the cylinder is not affected by the interlayer clearances.