Oil whip and resonance are the common faults of a rotor system. The faults directly affect its normal operation and can cause serious accidents. Based on the regularity of oil whip and resonance of the rotor system, a sensitivity study of the frequency reliability of the system is conducted. The technique developed utilizes random perturbation technology, reliability theory, and sensitivity technology. The reliability mode and the failure probability of the rotor systems are defined. The second-order joint failure probability is obtained using numerical integration methods. The variation regularities of the reliability are obtained and the influences of random parameters on the reliability of the rotor system are studied. The method presented provides a theoretical basis for the frequency reliability sensitivity design of the rotor system. A numerical example is analyzed to show the effectiveness of the proposed method.

Abstract. On the basis of the dynamic equations of rotor system with pedestal looseness, rub impact and crack, the random response method of rotor system with pedestal looseness is researched. The method is based on stochastic perturbation theory and the Kronecker algebra, matrix calculus and random perturbation are used. the reliability of rubbing for the coupling fault of rotor system was studied by Applying stress-strength interference theory and fourth-order moment technology, and on the basis of reliability analysis, the reliability sensitivity of rub impact on coupled fault rotor system is discussed by combining the sensitivity technology . IntroductionMultiple fault often occur in the working process of rotating machinery at the same time, coupling faults can reduce the stiffness and strength of the rotor system, which will cause the occurrence of major accidents. So, research on the reliability sensitivity analysis of fault rotor system will have the theoretical and engineering-oriented significance for the rotating machinery [1].In the paper, the model of rotor system with coupled faults has been built. On the basis of the rotor system model, the random response method of rotor system with coupled faults is presented.The first four moments of the response and the state function are obtained using the statistical fourth-moment method. The reliability sensitivity analysis method of rotor system with coupled faults is presented. Numerical results are also presented and discussed.

This article introduces the OptiStruct iterative algorithm, and the corresponding sensitivity analysis. Combined with the practical application of engineering, important support structures are used for topology optimization design by HyperWorks. The results show that in the case of meeting production requirement, the volumes of structures are reduced significantly, material distribution is more reasonable, lightweight design of component is achieved, theory reference is provided to improve and optimize device structure.Key words: Topology Optimization; OptiStruct; Sensitivity Analysis; HyperWorks OverviewContinuum structure main beam, shell and plate, its topology optimization design is one of the new direction in the field of structure optimization design, The topology optimization of continuum structure is mainly divided into two aspects of research: Mainly study abroad in the global stiffness topology optimization problem under the restriction of volume, and domestic research on the local stress intensity under the restriction of topology optimization problem [1][2] .Based on the research and development of ham sausage packaging visual inspection equipment as the object, Application of OptiStruct iterative algorithm and the corresponding sensitivity analysis, Finally in the HyperWorks topological optimization, and the finite element analysis have been carried out to verify the results of optimized, to illustrate the feasibility of the optimization results. 388