含空心纤维热电复合材料的能量转换效率及力学性能

空心纤维常用于热电复合材料的结构设计。纤维附近产生的不均匀温度场会引起局部热应力集中，威胁材料的可靠性并可能导致结构失效。本文采用圆环夹杂模型，研究了含空心纤维热电复合材料在均匀远场电流和能流作用下的力学响应。基于非线性全耦合的热电本构方程，利用复变函数中的级数法得到了纤维和基体中热电场和应力场的解析解。通过数值算例，分析了空心纤维的传导能力和几何尺寸对温度场、应力场和局部热电转换效率的影响。结果表明：随着空心纤维内径和界面热阻的增大，界面周围的应力场增大，但并不改变应力场的分布趋势。此外，我们发现：温度分布和应力场对几何参数比对界面热阻更为敏感。

Energy conversion efficiency and Mechanical properties of thermoelectric composites with hollow fibers

Hollow fibers are often used in the design of thermoelectric composites structures. The presence of hollow fibers usually leads to an inhomogeneous temperature field in corresponding thermoelectric materials and local stress concentration near the fibers, which threatens the reliability of the thermoelectric materials and may eventually cause their failure. In this paper, the hollow fiber is simulated as a annular inclusion. The energy conversion efficiency and mechanical response of a thermoelectric matrix with a hollow fiber under remote current and energy flow are studied. Analytical solutions for the thermoelectric field and stress field in the composite are obtained, in the case of fully coupled nonlinear thermoelectric constitutive equations, by using the complex variable formalism and the series expansion method. The effects of the conductivity and geometric parameters of the hollow fiber on the temperature distribution, stress field and thermoelectric conversion efficiency are discussed in numerical results. It is shown that the stress around the interface increases with the inner radius of hollow fiber and interface thermal resistance, whilst the stress distribution keeps the same. In addition, it is found that the geometric parameters can have a more significant effort on the temperature field and stress field, if compared with the interface thermal resistance.