The Investigation Of Assemblage Intensity And Mode For Marine Diesel Engine

The diesel engine is one of the most important components,the performance of the diesel engine have a direct effect to the driving safety of the automobile. The engine block is the main body of the diesel engine,its stiffness and dynamic characteristics ensure the normal working of the diesel engine. Airframe assembly sequence and the crosshead guide plate assembly of deformation on the performance of the diesel engine has an important influence, During the course of design,in order to improve and optimize design project and achieve satisfied design effect,we must have a relatively accurate estimate.The FEM (finite element method) is a common numerical analysis method, and it is the most reliable and effective method of studying the stress problem of complex construction. In this paper, marine diesel engine body as the research object, the finite element method on the whole body in four ways bolt preload case, the mechanical properties of the body for analysis; and study the role of bolt preload and explosive, the plane seat, rack mechanical properties.The process of boundary condition is very important in the FEA,which straight determines the solving precision. This thesis introduces pretension element to simulate the pretension force of each connecting bolt and sets up a lot of contact elements in the match surface of parts, so obtains more reasonable results. Eventually, we find the stress variable rule of the dangerous position and the deformation data of corresponding position using the specific post processing of FEA software. The result of strength checking indicates that all the engine block subassembly are secure.Finally, the analysis from the middle to both sides of the tension from both sides toward the middle taut, tense sequence from front to back and from back to front in turn four kinds of strain on the machine seat frame assembly mode deformation. Symmetrical and assembly, the body of stress and the smaller displacement.The analysis results in the engine assembly, the more appropriate way for symmetric assembly of the assembly.