较好地解决了具有独立失效模式的多自由度非线性随机参数振动系统的可靠性灵敏度分析问题．应用四阶矩技术和Edgeworth级数把未知的响应和状态函数的概率分布展开成标准的正态分布的表达式，从而确定了系统的可靠度和可靠性灵敏度，并放松了随机参数的分布概型和激励类型．

Techniques from the perturbation method, the second moment and reliability-based design theory are employed to present a practical and effective method for the reliability-based design of automobile components. The theoretical formulae of reliability-based design of automobile compo-nents are obtained. The reliability-based design methods are employed to develop the reliability design of atttomobile axles and springs. The corresponding program can be used to obtain the reliabilit\-based desien parameters of automobile components accurately and quickly,

On the basis of the rubbing dynamics equation of the Jeffcott rotor stator model with imbalance, the sensitivity of rotor stator systems with rubbing is studied. The effect on sensitivity of shaft stiffness and damping, stator stiffness and damping, radial clearance, and stator radial stiffness is investigated. The numerical results are presented and discussed.

Techniques from the perturbation method, the reliability-baseddesign theory and optimisation techniques are employed to present apractical and effective method for the reliability-based optimisation ofautomobile components. The theoretical formulae for reliability-basedoptimisation are obtained. The most probable point perturbation method(MPPPM) and reliability-based optimisation theory are employed todevelop the reliability-based optimal design of automobile components.Two examples are used to illustrate the reliability-based optimisationformulation and demonstrate the method. The accuracy of the approachproposed is evaluated by comparing their results to that obtained fromMonte Carlo simulations (MCS)

This paper presents the dynamics problems of stochastic vibratory machine systems. The random responses of the vibratory machine systems with stochastic parameters subjected to random excitation are researched using a stochastic perturbation method. The numerical results ,are obtained. The dynamic characteristics of nonlinear stochastic vibratory machine are analyzed.