Cracks always form at the interface of discrepant materials in composite structures, which influence thermal performances of the structures under transient thermal loadings remarkably. The heat concentration around a cylindrical interface crack in a bilayered composite tube has not been resolved in literature and thus is investigated in this paper based on the singular integral equation method. The time variable in the two-dimensional temperature governing equation, derived from the non-Fourier theory, is eliminated using the Laplace transformation technique and then solved exactly in the Laplacian domain by the employment of a superposition method. The heat concentration degree caused by the interface crack is judged quantitatively with the employment of heat flux intensity factor. After restoring the results in the time domain using a numerical Laplace inversion technique, the effects of thermal resistance of crack, liner material, and crack length on the results are analyzed with a numerical case study. It is found that heat flux intensity factor is material-dependent, and steel is the best liner material among the three potential materials used for sustaining transiently high temperature loadings.

中文翻译：

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复合管中圆柱界面裂纹周围的热量集中

裂纹总是在复合结构的不同材料的界面处形成，这在瞬态热载荷下会显着影响结构的热性能。双层复合管中圆柱形界面裂纹周围的热集中尚未在文献中得到解决，因此本文基于奇异积分方程法进行了研究。由非傅立叶理论推导的二维温度控制方程中的时间变量使用拉普拉斯变换技术消除，然后通过叠加方法在拉普拉斯域中精确求解。利用热通量强度因子定量地判断由界面裂纹引起的热集中度。使用数值拉普拉斯反演技术在时域中恢复结果后，通过数值案例研究分析了裂纹的热阻，衬里材料和裂纹长度对结果的影响。已经发现，热通量强度因子取决于材料，在用于承受瞬态高温载荷的三种潜在材料中，钢是最好的衬里材料。