High-temperature pipelines are susceptible to defects due to the long-term service in high-temperature environments. The guided wave technology is promising for online non-destructive testing. Before implementing it in engineering, it is essential to better understand guided wave characteristics, especially attenuation, which significantly decreases the test distance and the resolution. However, describing the large attenuation is challenging due to the strong thermoelastic coupling, resulting in limitations of available models. To address these limitations, this paper aims to introduce a memory-dependent generalized thermoelastic model for investigating guided waves propagating in a hollow cylinder with temperature-dependent material properties. The analytical solutions are obtained using the Legendre polynomial method. The influence of the memory-dependent effect, temperature variation, and boundary conditions are studied. Some interesting findings are revealed: (1) The time delay factor is more dominant when adjusting and to accurately describe guided wave propagation at high temperatures. (2): The mode conversion is accompanied by the attenuation and group velocity jump when the adjacent flexural torsional and longitudinal modes intersect, which is advisable to avoid when choosing the excitation frequency. (3) The relationship between phase velocity and attenuation versus temperature for quasi-elastic modes is nonlinear, while that for thermal modes is approximately linear.

中文翻译：

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基于热传导模型的记忆相关导数的具有温度相关特性的空心圆柱体内的广义热弹性波响应

高温管道由于长期在高温环境下使用，很容易出现缺陷。导波技术在在线无损检测方面具有广阔的前景。在工程实施之前，有必要更好地了解导波特性，特别是衰减，它会显着降低测试距离和分辨率。然而，由于强热弹性耦合，描述大衰减具有挑战性，导致可用模型的局限性。为了解决这些限制，本文旨在引入一种依赖于记忆的广义热弹性模型，用于研究在具有温度依赖材料特性的空心圆柱体中传播的导波。使用勒让德多项式方法获得解析解。研究了记忆相关效应、温度变化和边界条件的影响。一些有趣的发现被揭示：（1）在调整和准确描述高温下导波传播时，时间延迟因子更占主导地位。 (2)：模态转换伴随着相邻弯扭模态和纵模态相交时的衰减和群速度跳跃，在选择激励频率时建议避免这种情况。 (3) 准弹性模态的相速度和衰减与温度的关系是非线性的，而热模态的相速度和衰减与温度的关系近似线性。