缝合三明治热防护结构热力耦合仿真分析

为了研究缝合三明治热防护结构应用于高超声速技术领域时的热力性能及内在机制,基于代表性体积单元模型建立了模拟热力联合载荷作用下响应的有限元仿真分析方法,分析了结构内部的温度和应力分布,以及随载荷历程的演化情况。研究结果表明：加热面温度为1 073 K时,缝合三明治热防护结构能够有效起到隔热作用；缝线作为“热通道”对隔热性能的削弱影响不明显,但不同组分间的热膨胀不匹配会引起应力集中；面板和夹芯界面处的拉应力以及夹芯内部较高的应力水平可能会导致结构损伤和失效。

Thermal-mechanical Coupled Simulation Analysis of Stitched Sandwich Thermal Protection Structure

This paper is aimed at investigate thermal and mechanical properties and internal mechanisms of stitched sandwich thermal protection structure applied in the hypersonic technology field. Based on representative volume element model, a finite element simulation analysis method was established to simulate the responses under combined thermal and mechanical loads. Internal temperature and stress distributions of the thermal protection structure were analyzed, as well as the evolutions with the loading history. The results show that the stitched sandwich thermal protection structure can effectively play the role of heat insulation when heating surface temperature was 1 073 K. Reducing effect of stitches as thermal channels on insulation performance is limited. however, thermal expansion mismatches of different components can result in stress concentration. Tensile stress state at the skin/core interfaces and possibly higher stress level inside core may cause damage and failure of the structure.