时间：2020-11-06 10:00
地点：九里1号综合楼240
报告人：王骥
个人简介：
王骥，宁波大学钱江学者特聘教授、中国力学学会电子电磁器件力学专业工作组的创建组长、国际电工委员会(IEC)技术委员会专家、宁波市压电器件技术重点实验室创建主任、国际期刊Structural Longevity主编，长期从事压电声波器件结构的设计和分析理论的研究，主持国家自然科学基金重点项目、浙江省重大科技攻关项目、浙江省重点科技创新团队和宁波市智能制造2025等多个科技项目。其主持的石英晶体研究项目在日本精工爱普生(Seiko Epson)公司获得公司科研二等奖，在石英晶体谐振器相关的研究工作有多项美国专利和中国发明专利。
讲座内容：
Mechanical components of devices and fine machinery are increasingly subject to significant accelerations in normal services and operations with highly mobile platforms such as vehicles, aircrafts, rockets, missiles, satellites, and other moving environments. With large accelerations, it is inevitable that mechanical vibrations can be driven to nonlinear states, resulting strong variations of vibration characteristics including frequency and modes shapes. Naturally, applications of many devices can be affected if these modified vibrations are not considered in the monitoring systems configuration and correction of signals.The general principle of evaluation of acceleration effect is to consider the nonlinear deformation of vibrations and the external acceleration is treated as the additional stresses. In this study, we start from the exact equations of motion with an external acceleration in the thickness-shear vibrations of an infinite isotropic plate, and the approximate solutions of frequency and displacements due to the acceleration are obtained. The vibration frequency under acceleration is obtained through the deformation due to acceleration by approximation with the perturbation method. The analytical solution with good accuracy is obtained and the frequency variation is evaluated with the simple relationship between deformation, acceleration, and frequency. This study provides an analytical solution to such problems in addition to the popular finite element method in a consistent manner.
