The Modeling Analysis And Multi-objective Design Optimization Study For Centralized Lubrication Systems Based On Isight

With the increasing complexity of the mechanical products and market competition, the traditional serial design method is more and more difficult to meet the urgent needs of the times. Multidisciplinary design optimization(MDO), which has emerged and got improved since 1980 s, decomposes a complex mechanical system to sub-systems and fully explores and makes use of the coordination effects of the mutual coupling between disciplines to obtain the global optimal solution. Centralized lubrication system design involves the mechanical structure, transmission, hydraulic, control, and other fields. The traditional design separates the links between the various disciplines artificially, and tends to reduce the overall system performance. Therefore, the use of MDO thought in decomposition, coupling and modeling analysis of centralized lubrication system is of great significance.In this paper, the mathematical model and simulation model of centralized lubrication system were constructed and analyzed. The proxy model was obtained for the complex and time-consuming process of system analysis through approximation techniques. The MDO integration platform was built based on Isight. Different decomposition strategies and optimum algorithms were used for the multi-objective and single objective analysis.The specific work mainly includes the following five parts:(1) The decomposition strategies and optimum algorithms in MDO analysis were introduced in detail. The construction principles and characteristics of different decomposition strategies were analyzed. The advantages and disadvantages of numerical algorithms to intelligent algorithms were compared. MDF and CO strategies were selected to analyze in terms of centralized lubrication system features.(2) The mathematical models of eccentric mechanism and plunger mechanism were analyzed. Because of the vibration of lubrication pump in work, the modal of pump seat was analyzed. Surrogate models for the complex models were created with approximation approaches.(3) A MDO platform was established through integration of professional analysis software in various fields by the software Isight. MDF and CO strategies were respectively used to establish the integrated optimization framework of piston-cylinder, and the different results were contrasted.(4) The lightweight design of plunger mechanism was conducted. The plunger mechanism was decomposed into a system-level and three sub-systems through an improved coordination optimization method. SolidWorks was used to establish three-dimensional modeling for sub-systems and AnsysWorkbench used to analyze its stress, strain, and fatigue life. The optimal Latin hypercube method and response surface method were used to obtain the approximate proxy models of sub-systems, and the integration framework based on Isight was used to complete optimization analysis.(5) In the end, as there existed multi-objective optimization problems in MDO, the advantages and disadvantages of normalization algorithm, NCGA algorithm and NSGA-II algorithm were compared. The Pareto solution set of the plunger mechanism were obtained by using NSGA-II algorithm, and the optimal solution scheme was chosen.The optimal design method in this paper can achieve the goal and meet performance requirements in all aspects for centralized lubrication systems. This study has some reference values for the centralized lubrication systems design, and provides another dimension for the research and application of the centralized lubrication systems.