Structural Design Of Trailer Frame Based On Random Vibration Damage Analysis

With the rapid growth of trailer transportation,the center axle trailer is widely used in transportation of commercial vehicles.Special vehicle manufacturers should not only consider increasing vehicle speed,loading coefficient and transportation cost,but also consider improving transport safety,ride comfort and reliability.Due to the heavy weight,large structure size of the trailer's bogie frame and load capacity,the natural frequency characteristics of the elastic bogie frame and road excitation directly affect the dynamic response properties of the vehicle system,cause local fatigue damage of frame easily.Therefore,with the combination of the strain electrical measurement technology,finite element analysis,muti-body dynamic simulation and random vibration fatigue analysis,use their application to the study of trailer system dynamic response and its structure fatigue strength have engineering significance.Main contents of this thesis are follows:1.The strain sensor and acceleration sensor are installed in the critical position of the trailer frame,in order to understand fully vibration situation of the trailer frame during each operation.Then,the actual stress and acceleration of the frame is measured by using strain electrical measurement technology and vibration test system test system.At last,the test data is provided to verify the reliability of finite element analysis.2.The finite element model of trailer frame is established.The stress and deformation of the frame are obtained under four different operation conditions through the dynamic statics,and the preceding ten steps natural frequency and frequency response function on the critical position of the frame are obtained through modal analysis.The accuracy of the frame's mechanical model is verified by experiments3.The ADAMS CAR software is used to model the whole trailer frame.Then,the muti-body dynamic simulation is carried out to analyse the spectra of force on the connection points between the frame and suspension.Then,extract the force load spectrum of connection points and acceleration spectrum of marked points under high-speed road,bump road and mountain road.Finally,the reliability of the frame's muti-body dynamic model is verified by test date and provide date base for fatigue analysis.4.Doing vibration fatigue analysis for frame.The frequency analysis is carried out in order to obtain the power spectral density of the force spectrum.Then,combined with dynamic analysis of frame frequency response characteristics and the structure of the material S-N curve,on the basis of Dirlik model and FKM method correction in nCode Design Life software,then estimate fatigue life and the driving mileage under each road condition,At last,take improvement for weak position of local fatigue strength of structure.