A Reliability Study On The Piston Rod Of A Reciprocating Air Compressor Based On The Multi-field Coupling

As one of the frequent fatigue failure parts in all components of a reciprocating compressor,the piston rod's reliability has always been a research hot topic.With the development of computer simulation technology,the innovation of theory knowledge and the optimization update of commercial simulation software,people have more choices in solving the problem.Mechanical reliability describes the ability of a mechanical system or module to operate normally within a specified condition and period,usually described as a "Bathtub Curve".In this paper,the simplified three-dimensional model of W-1.0/8 type reciprocating air compressor is set up,and the failure mechanism,influencing factors and reliability optimization design of the piston rod are studied.The specific research work is as follows:(1)Aim at the research subject of reciprocating compressor piston rod reliability,we find the innovation point of this paper by studying the theoretical basis of compressor failure mode,piston rod failure form,research method and so on,.Through the analysis and induction of literature data,the research contents and methods are determined.The further division of the research content and the validity of the research method are realized by the mathmatics modeling and simulation experiment,and the purpose of combining the theory and the reality is achieved by constructing the reliability parameter sensitivity analysis system and the reliability optimization design system.(2)The fracture failure of the piston rod of W-1.0/8 type reciprocating air compressor was put forward by the project group,and the three-dimensional model of the compressor was established.The single physical field(Structural Mechanics)and the flow-solid-heat three field coupling(multibody dynamics)simulation analysis were carried out respectively in the Comsol Multiphysics,and the single field action of the piston rod was compared with three field coupling action,and the variation of the Von Mises Stress under multi field coupling is presented.The simulation results show that under the same condition,the maximum value of the equivalent stress of the piston rod is larger than that of the single field under the interaction of multi field coupling,and it is most close to the stress in the actual work of the W-1.0/8 type reciprocating air compressor and explore the mechanism of the failure of piston rod(3)Establish the reliability target function which takes the stress as the index in the piston rod work and the constraints of the temperature,cylinder pressure and the yield stress of the piston rod,the improved Ant Colony Algorithm is used to find the best working state of the piston rod with the Matlab,and the validity of the method is verified.(4)Built the optimal design system of the piston rod based on the two development function of Comsol5.2a.