Cimmelli Vito Antonio
Department of Mathematics, Computer Science and Economics, University of Basilicata, Viale dell'Ateneo Lucano, 10, 85100 Potenza, Italy.
Entropy (Basel). 2023 Jul 19;25(7):1084. doi: 10.3390/e25071084.
We propose a thermodynamic model describing the thermoelastic behavior of composition graded materials. The compatibility of the model with the second law of thermodynamics is explored by applying a generalized Coleman-Noll procedure. For the material at hand, the specific entropy and the stress tensor may depend on the gradient of the unknown fields, resulting in a very general theory. We calculate the speeds of coupled first- and second-sound pulses, propagating either trough nonequilibrium or equilibrium states. We characterize several different types of perturbations depending on the value of the material coefficients. Under the assumption that the deformation of the body can produce changes in its stoichiometry, altering locally the material composition, the possibility of propagation of pure stoichiometric waves is pointed out. Thermoelastic perturbations generated by the coupling of stoichiometric and thermal effects are analyzed as well.
我们提出了一个描述成分梯度材料热弹性行为的热力学模型。通过应用广义科尔曼 - 诺尔程序来探索该模型与热力学第二定律的兼容性。对于手头的材料，比熵和应力张量可能取决于未知场的梯度，从而产生一个非常通用的理论。我们计算了耦合的第一声和第二声脉冲在非平衡态或平衡态下传播的速度。我们根据材料系数的值来表征几种不同类型的扰动。在物体变形会导致其化学计量发生变化从而局部改变材料成分的假设下，指出了纯化学计量波传播的可能性。还分析了由化学计量和热效应耦合产生的热弹性扰动。
