Dynamic Optimization Design Of Loader Structure

The loader structure system consists of front and rear frames,working devices,and assumes almost all internal and external loads.It is one of the key system components of the loader.Its rationality and reliability are closely related to the whole performance.The rear frame is the installation base for main components of loader,and the static and dynamic characteristics of it is particularly important.In this paper,the rear frame of a wheel loader is taken as the object of study.Based on structural statics and dynamics,the finite element method is used as the tool to analyze the mechanical and finite element analysis of the rear frame of the loader.Analysis of harmonic response analysis,topology optimization and size optimization,improved the rear frame of the static and dynamic performance.The main contents are as follows:1.The static condition and dynamic excitation of the rear frame are analyzed.According to the three kinds of harsh conditions of the rear frame,the mechanics model of each condition is established,and the simplified three-dimensional geometric model of the rear frame is established.The finite element model is established by selecting the appropriate unit type and constraint mode.Analyze the main excitation force in the work of the loader.2.The dynamic characteristics of the rear frame are analyzed,and the natural frequency and mode of the first ten steps of the rear frame structure are given.The vibration of the rear frame between the engine and the cab is studied by means of harmonic response analysis,Which provides a reference for the dynamic evaluation of the rear frame.3.In order to improve the static and dynamic characteristics of the rear frame,the static optimization method is used to transform the static optimization target and the first three frequency optimization target into a single target for static and dynamic multi-target topology optimization.Based on the volume ratio,the natural frequency and the flexibility,the reasonable topology optimization results are obtained,and a new rear frame model is designed.The static and dynamic performance is significantly improved compared with the original frame,but the quality increases.4.To reduce the quality of the rear frame,to its sensitivity analysis and size optimization.The parameters of the parameters of the rear frame are analyzed,and the parameters with great influence on the static and dynamic characteristics of the structure are selected as the design variables,and the size is optimized with the minimum quality.The optimized natural frequency of the rear frame avoids the engine excitation and avoids Resonance,and the mass decreased from 492Kg to 372Kg(24.4%),the effect of light weight.The research of this subject is to improve the dynamic characteristics,avoid the resonance,make the rear frame material get the optimal distribution and reduce the development cost under the performance index of the static strength of the rear frame by means of finite element method and dynamic structure optimization theory,Shorten the design cycle,guide the design of the new rear frame.