Fatigue Analysis Of A Light Truck Tank Based On Measured Road Spectrum

As an important component in a car,the fuel tank has a crucial impact on the safety performance of the car.During the actual use of the fuel tank of a truck,the external vibration environment is complicated.The fuel in the tank is shaken violently,and the partition in the fuel tank is prone to fall off,which may cause fuel leakage and even fire.The fuel tank must ensure its safety performance and service life,so the vibration fatigue analysis of the fuel tank has important research significance.Aiming at the problems of tank tearing and fuel leakage in the road test of a light truck fuel tank,this paper conducts a finite element simulation analysis and related tests on the fuel tank,and studies the vibration fatigue of the fuel tank based on the measured road spectrum.The research content is as follows:(1)Introduce the background and significance of the subject,the research methods of fuel tank dynamics and the research status of fatigue analysis based on road spectrum.(2)Based on the relevant knowledge of fluid mechanics,acoustics and structural mechanics,based on the theory of finite element calculation and analysis,the dynamic equation of fluid-structure interaction is derived.Based on the related theoretical knowledge of fluid-solid coupling,ANSYS software is used to calculate each mode of the fuel tank at different filling-ratios.Focus on the vibration analysis and vibration test of the fuel tank filled with 50% fluid,and study the vibration characteristics of the fuel tank,verified the accuracy of the finite element model and analysis method.The vibration response results at the welding point of the fuel tank were extracted and analyzed briefly.(3)When testing at the site,collect and process road spectrum data for five types of enhanced pavements.The acceleration sensor is used to measure the time-domain data of the fuel tank,and there are some signals in the road spectrum data such as glitches,zero drift,temperature drift and local overruns,which should be checked and effectively corrected.The Fourier transform is used to convert the time-domain data into corresponding frequency-domain PSD load data and processed.(4)The fatigue analysis of the fuel tank is also performed under the condition of 50% filling-ratio.Harmonic response analysis is performed on the fuel tank to obtain the stress distribution.Combined with fatigue life analysis theory,the S-N curve characteristics of the material and the PSD load spectrum excitation are imported into nCode DesignLife for analysis,and the fatigue life of the fuel tank structure under reinforced road surface is obtained.In this paper,the dynamic characteristics of a 50% fuel-filled fuel tank are studied,and the vibration fatigue of the fuel tank structure is analyzed based on the measured road spectrum to provide a reference for the fatigue characteristics of the fuel tank.