智能压电结构接触-碰撞瞬态响应及其波动特性研究

In the working process, intelligent piezoelectric structure usually is under pure mechanical repeated contact-impact loading or pure electric impact loading or electromechanical impact loading. The layer piezoelectric composite occurs vibration of with high frequency and the elastic transient wave propagation. The precision of piezoelectric actuator and the strength of structure will be decreased. The present application program aims to these transient dynamics problems, and take the inertial impact actuator as investigation object. Considering the mechanical-electric coupling effect of piezoelectric material and the contact effect of the local contact zone of colliding bodies, a dynamic substructure theory for the intelligent structure consisting of piezoelectric stack and elastic layer under contact-impact is developed. The theory is used to investigate the elastic dynamics behaviour of intellignet piezoelectric structure. The establishment of continuum body impact model and quasi-distribution parameter impact model, the determination of the algorithm of repeated transition between contact and separation state, and the computation of contact stress are all solved. By incorporating with the theory of stress waves, the propagation of the transient waves induced by impact or voltage and the interaction mechanism between these two types of waves are analyzed. The rule of the influence of wave propagation on the strength of structure is discussed. By the above investigations, the theory studies on the contact-impact transient response and the characteristic of wave motion of intelligent piezoelectric structure are completed. Meanwhile, the experimental setup and measurement system are established to validate the numerical results, which is used to measure the structure transient response. The study results of the present program can be a theory basis for the transient dynamics design of intelligent piezoelectric structure.

智能压电结构在工作过程中往往会承受反复的接触-碰撞和电压激励等冲击载荷的单独或同时作用，容易导致压电层合结构出现高频振动和弹性瞬态波在结构中传播等现象，降低压电驱动器精度和结构强度。本项目针对该问题，以压电惯性式驱动器为研究对象，考虑压电材料的机电耦合效应和柔性碰撞体间的接触效应，提出多层复合压电体的动态子结构接触-碰撞理论，研究智能压电结构的接触-碰撞弹性动力学行为。重点解决能描述波动效应的"连续体模型"和"准分布参数模型"的建立、接触和分离状态反复切换算法的编制以及接触力等瞬态响应的计算等基础理论问题。结合应力波理论分析碰撞激发瞬态波和电压激发瞬态波的传播及其相互作用机理，探索波传播对结构强度的影响规律，实现对智能压电结构的接触-碰撞瞬态响应及其波动特性的理论研究。同时搭建实验装置和测量系统，开展结构瞬态响应的实验研究，验证理论分析结果，为智能压电结构的瞬态动力学优化设计提供科学依据。

压电智能结构在工作过程中往往会承受反复的接触-碰撞和电压激励等冲击载荷的单独或同时作用，容易导致压电层合结构出现高频振动和弹性瞬态波在结构中传播等现象，降低压电驱动器精度和结构强度。本项目针对该问题，以冲击式压电驱动器为研究对象，考虑压电材料的机电耦合效应和柔性碰撞体间的接触效应，提出多层复合压电体的动态子结构接触-碰撞理论，研究压电智能结构的接触-碰撞弹性动力学行为。建立了结构的接触-碰撞模型、接触和分离状态反复切换算法的确定以及接触应力瞬态响应的计算等基础理论问题，并结合应力波理论和有限元理论分析了碰撞激发瞬态波和电压激发瞬态波的传播及其相互作用机理，探索了波传播对结构强度的影响规律以及周期性压电结构对机械波的滤波特性。实现了对压电智能结构的接触-碰撞瞬态响应及其波动特性的理论研究。同时搭建了实验装置和测量系统，进行结构瞬态响应的实验研究。本项目的研究成果为压电智能结构的瞬态动力学优化设计提供理论依据，将压电智能结构的设计方法由振动模态分析法推进至了瞬态动力学分析法。