Abstract. The rub-impact fault of Jeffcott rotor system which is generally made of an elastic shaft with supported by two bearings at ends and a lumped mass at the mid-span of shaft is the main research subject of this paper. The mechanical model and finite element model of a lump mass at the mid-span of shaft is set up. The dynamics of it are studied by nonlinear finite element method under the rub-impact conditions, and by investigating the effects of stiffness of stator and the clearance between rotor-stator. From the study results, use finite element method to study the rotor system failure problem is intuitive and convenient, high accuracy, high reliability, can be widely applied.
It expounded the design quality connotation, product generalized quality was “the integrated embodiment of product function and performance”, the generalized product quality and the whole function and performance are equivalent. Clearly it made the design quality concretized into the product function and three performances. Expounded the concept of product design quality control, analyzed the influencing factors of product design quality, formed the design idea of quality control; aiming at the existing problems of traditional product design, established design quality control preliminary model by applying systematic design theory.
To study the dynamic characteristic of a vibration compaction system, we first build up a double DOF model, then it is solved with transfer matrix method and the mathematical description was carried through on the status of every units in the model. Through the analysis of simulation data with simulation software, the data with the transfer matrix equation is the same as data with simulation software. This made clear that the transfer matrix model approaches to the practical circumstances and it bears important referencing value to the dynamics analysis of the correlation system.
Looseness fault can occur in rotor part, bearing and pedestal for the vibration caused by alteration of operating craft and inappropriate installation. In the paper, a new pedestal looseness model is proposed by comprehensively considering the advantages and disadvantages of current models of pedestal looseness. By using nonlinear finite element method, the nonlinear characters of overhanging dual-disc rotor bearing for pedestal looseness fault are studied. The work has important significance on safe running and prolonging the life span of machines.
When discussing the rubbing issue of rotor system, the effect of nonlinear rubbing force is needed to be considered. In this paper, modeling and numerical simulation were carried out by using the nonlinear rubbing force based on Hertz contact theory, and researching the dynamic response of fault rotor system in the conditions of the different rubbing stiffness. Through the analysis we found that, in the case of larger rubbing stiffness the result simulated by using rubbing force model based on Hertz contact theory has stronger nonlinear and more obvious rubbing feature, compared to the rubbing model of linear stiffness. It is beneficial to determine the occurrence of rubbing. Refer to the relevant experimental results, the correctness of the Hertz rubbing model and the feasibility of applying it in the modeling of rubbing rotor system were confirmed.
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