Plait Of Loading Spectrum For A Certain Type Of Loader Hydraulic System

Loading spectrum is the load-time history which can reflect the true working conditions, that is, the stress or strain of component suffered. It is not only the premise and basis of fatigue strength calculation and reliability analysis, as well as a prerequisite to solve the problem about determination and prolongation of structure life, computer-aided design, but also the basis of theoretical analysis and the fatigue test of structure. At present, there are lots of researches on the loading spectrum both at home and abroad, most of them concentrate on the fields of aviation, mechanism, bridge and road, and mainly analyse stress under the working environment and working load for mechanical components, but the study about hydraulic system is none. This article will take the loader hydraulic system as research object; plait the loading spectrum which reflects the actual characteristics of the working load.There are not only contacts between the plaiting methods on entire system and single component, but also differences. Loading spectrum of component reflects the stress or strain of component suffered, and the system loading spectrum reflects the system load that changes in the course of time, the nature of load is mainly determined by the characteristics of system. Under normal working condition, the characteristics of the hydraulic system are reflected by the change of fluid pressure, flux and temperature derectly. There is no experience to follow on plaiting complex system loading spectrum. According to the actual condition of loader collection test, this paper mainly research the loading spectrum of pressure within the hydraulic system of loader which changes in the course of time. The detail tasks include experiment design and processing of test data such as the arrangement of sampling points, stable treatment, the elimination of outliers, determination of the maximum load as well as the choice of counting method.The general guiding principle is that the loading spectrum must reflect the real working conditions of the load - time history.By deep survey and research, this paper widely discusses the development of the loading spectrum at home and abroad, as well as the achievements in the various fields, and generalizes the methods about the plait process of loading spectrum. On the base of loading spectrum achievements, combining the characteristics of loader's hydraulic system and the using-requirements on loading spectrum of hydraulic system, this paper attempts to plait the loading spectrum of the pressure on the hydraulic system for the first time, the main research content includes:on the basis of a deeper understanding about the composition and working principle of the loader hydraulic system,analysing the system characteristics and the working cycle according to the pressure load; generalizing and comparing the related theories about the plait of loading spectrum , including data preprocessing, determination of the sample length, analysis of error, comparison of the counting methods, analysis of the effects of loading sequence; in accordance with the characteristics of the pressure load, choosing a better way to plait the loading spectrum and writing the corresponding procedures,seting up the loading spectrum for the hydraulic system of loader initially. On this paper, loading spectrum can be obtained in order to provide the necessary base for further achievement about simulated load test of the whole loader, accelerated life test and study of reliability, additionally it will take valuable exploring experience for the plait of loading spectrum of system.