A multilevel multiobjective coordination matching design technique for the main bearing assembly structure of a diesel engine.

The main bearing assembly structure is one of the most important main load‐bearing structures of a diesel engine. The working loads of this structure increases dramatically with the increase of the power density of diesel engines, resulting in the problem of unsatisfactory reliability coordination design in restricted design space, while the mechanisms for coordinated design are still at the blank stage. Aiming at the problem, a multilevel multiobjective coordination matching design technique is innovatively proposed in this paper. This technique is characterized by a multilevel multiobjective coordination evaluation system for the assembly structure and its components based on the improved analytic hierarchy process. The finite element model and mathematical model of the main bearing assembly structure are established to realize the joint of finite element technology and optimization technology for coordination matching design. By carrying out verification experiments, the strength coordination, deformation coordination and contact strength coordination of the assembly structure increase by 13.91%, 14.96%, and 2.63%, respectively, after matching design, while the mass coordination remains almost constant meeting the lightweight design requirements. The overall coordination of the main bearing assembly structure is improved by 11.10%, achieving the goal of matching design of the main bearing assembly structure. The results show that the coordination evaluation system can quantitatively characterize the coordination relationship of the assembly structure and the multi‐reliability of components, and it is a feasible coordination evaluation method. The demonstrated coordination evaluation system and coordination matching design modeling approach provide important theoretical guidance for the matching design of complex assembly structures. [ABSTRACT FROM AUTHOR]