Abstract Various caloric aspects of polycrystalline ferroelecrics are investigated, based on an efficient modelling approach. In this context, both linear reversible effects, leading to heating or cooling of the material, and nonlinear dissipation heating, being associated with ferroelectric domain switching, are considered. The semi-analytical approach focusses on the constitutive behavior of a polycrystalline representative volume element (RVE) under the impact of combined electromechanical loadings, incorporating mutual interactions of caloric and electromechanical fields within a framework of non-equilibrium thermodynamics. Temperature dependence of material coefficients is further taken into account. The so-called condensed method (CM) is employed to bridge the scales of domain wall motion within grains and grain interaction in the RVE. Results are compared to those of finite element simulations and experiments taken from literature, illustrating hysteresis loops and dissipation heating due to cyclic electrical loading. Additional findings illuminate the role of mechanical compression during electric cycling, behaviors of single vs. polycrystals, and separate the impacts of linear and nonlinear caloric effects.

中文翻译：

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具有相互非线性热-机电耦合的多晶铁电体的半解析尺度桥接方法

摘要 基于有效的建模方法，研究了多晶铁电的各种热量方面。在这种情况下，会考虑导致材料加热或冷却的线性可逆效应和与铁电畴切换相关的非线性耗散加热。半解析方法侧重于多晶代表性体积元 (RVE) 在组合机电载荷的影响下的本构行为，在非平衡热力学框架内结合了热量和机电场的相互作用。进一步考虑了材料系数的温度依赖性。采用所谓的凝聚法 (CM) 来弥合晶粒内畴壁运动的尺度和 RVE 中的晶粒相互作用。结果与从文献中获取的有限元模拟和实验的结果进行比较，说明由于循环电负载导致的滞后回线和耗散加热。其他发现阐明了机械压缩在电动循环过程中的作用、单晶与多晶的行为，并区分了线性和非线性热量效应的影响。