摘要
根据弹性梁的大挠度后屈曲理论,建立了多力耦合作用下加速度开关系统的动力学模型,由此设计了一种新型屈曲式微机械加速度开关.该开关采用倾斜微梁支撑敏感质量块,将两折叠梁固定于质量块的上下表面,从而保证了开关动作的方向性.利用弹性线方法计算了倾斜支撑梁结构大挠度后屈曲的非线性刚度,分析了气膜阻尼力和触点接触力对系统性能的影响,并运用数值方法对含有椭圆积分的强非线性系统进行了动态特性分析.仿真结果表明,所设计的开关响应时间低于6 ms,不稳定接触时间小于0.02 ms,在闭合状态下触点的接触力大于50 mN,与其他类型开关相比,它具有良好的阈值特性和接触可靠性,因此在惯性控制系统中具有广泛的应用前景.
Based on the post-buckling theory of large deflection beams, the nonlinear stiffness of a post-buckling beam is analyzed, then a novel micro-machined acceleration switch is designed. The switch consists of two oblique micro-beams with a mass in the middle, and two other folding beams are fixed on the top and bottom surfaces of the mass to ensure its single moving direction. While the acceleration reaches the threshold, the beams buckle to close the switch immediately, when the acceleration gets below a certain value, the switch opens quickly under the effect of the elastic force developed by the post-buckling beams. Compared with the switches of other kinds, the influences of the film damping force and the contact force on the switch system performance are taken into full consideration. The dynamic equation of the switch under coupled forces is established. And the dynamical simulation shows that the response time is less than 6 ms, and the unstable contact time is 0. 02 ms for the strong nonlinear system with elliptic integrals to indicate the good threshold characteristic and high contact reliability of the switch, furthermore the practical validity.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2007年第3期358-362,共5页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金联合基金资助项目(10476019)
关键词
微加速度开关
大挠度
后屈曲
非线性刚度
可靠性
micro-acceleration switch
large deflection
post-buckling
nonlinear stiffness
reliability
