层合压电智能结构中典型接触行为的研究

Multilayer piezoelectric, smart structures are widely used in new high-tech fields, such as in information industry, new energy industry and aerospace industry. Reliability is the most concerned issue for multilayer piezoelectric devices in services. Delamination and thermo-electro-elastic contact damage and instability are typical failure modes of these services when working in harsh environment, such as suffering from high external loading, strong electric field and high temperature. Based on our earlier work, the present proposal will develop the following theoretical models for typical contact behaviors occurring in multilayer piezoelectric plates and cylinders: (i) single, double receding contact and (ii) thermo-electro-elastic coupled contact and frictional sliding instability on the basis of Non-Fourier heat conduction law. The established models will be solved by applying wavelet-based numerical methods with high efficiency and accuracy, commercial FEM softwares and experimental approaches to reveal the influences of interface effect, layer-thickness size effect and strain mismatch effect on the delamination and thermo-electro-elastic contact damage and instability. The advantage of using functionally graded piezoelectric materials as interface to control various contact damages and instabilities will be exploited. Transient criterion of Non-Fourier thermal effect will be presented, and valid scope of Non-Fourier heat conduction law will be identified. Proof of the convergence of generalized integral with multiple parameters will be perfected. This proposal will not only provide benchmark references to the design and practical application of multilayer piezoelectric materials, but also enrich the contents of contact mechanics, heat transfer theory, mechanics and materials and multi-coupled mechanics.

层合压电智能结构广泛应用于信息、新能源和航空航天等高新技术领域。应用中的可靠性是此类器件备受关注的热点问题, 脱层和热电弹接触损伤及失稳是其在恒温和温变苛刻环境服役时常见的失效形式。本项目将研究层合压电板、柱结构如下典型接触问题：(i)单、双退让接触; (ii)基于非Fourier热传导理论的热电弹耦合接触及摩擦滑动失稳, 通过发展基于小波的高效数值格式、运用有限元软件和实验测试等方法求解, 揭示界面效应、层厚尺度效应和层间失配效应对脱层和热电弹接触损伤及失稳的影响规律; 发掘功能梯度压电材料做界面层改善各类接触损伤和失稳的巨大潜能; 探寻非Fourier导热效应的瞬态判据以及非Fourier导热的作用范围。本项目将完善含多参数广义积分收敛性等问题的数学证明。项目研究成果不仅将为层合压电智能结构的设计和实际应用提供理论基础和参考, 而且将丰富接触力学、传热学、材料力学和多场耦合力学的内容。

层合压电智能结构广泛应用于信息、新能源和航空航天等高新技术领域,其工作过程是典型的(热)电弹耦合接触问题。应用中的可靠性是此类器件备受关注的热点问题,研究其在恒温和温变苛刻环境服役时各种典型接触失效形式显得至关重要。本项目研究了层合压电智能结构的一些典型接触问题: (i)恒温时的双压头屏蔽接触、滑动摩擦接触、静/动态粗糙面接触、退让接触、压电准晶轴对称接触; (ii)基于非Fourier热传导理论的热电弹耦合接触。研究成果揭示了双刚性压头的屏蔽效应、压头基底效应、摩擦效应、粗糙度效应、退让效应、准晶效应等对压电智能结构接触损伤行为的影响规律; 阐明了非Fourier 热传导定律和经典Fourier 热传导定律之间的异同以及两类不同模型的适用范围; 给出了通过调节热传导梯度参数、热膨胀梯度参数、硬度梯度参数来优化功能梯度压电材料设计的指导性建议。另外,本项目还基于无网格径向基函数配点法,采用Tikhonov正则化法和拉格朗日乘子法发展了高效、准确的时间域数值反演方法以方便动态接触问题的研究。本项目在国际期刊发表论文15篇, 全部被SCI检索。项目研究成果不仅为层合压电智能结构的设计和实际应用提供了理论基础和参考, 而且也丰富了接触力学、传热学、材料力学和多场耦合力学的内容。