Dynamic And Static Strength Analysis Of Automotive Fuel Tank

In the modern engineering design, the finite element method is efficient andspeedily kind of moden engineering design aids. The finite element method used in theautomotive structural design will bring us dramatic effect in many aspects, shorting thedevelopment cycle of new cars, saving research and development costs. Automotive fueltank is the core component of the fuel supplying system, supports all kinds ofcomplicated loads coming from the road, bad design is easy to produce fatigue fracture,the research and design relies mainly on the experience to complete in the past, productupdates speed is slow, high cost.In this paper, combining the actual project and using CAD／CAE relatedtechnologies, finite element analysis is used in Automotive fuel tank. Through importinggeometric model, extracting midsurface, cleaning up geometry, dividing into grids,setting up material properties and thickness, simulating welded structures, according tothe actual load condition and setting the corresponding loads and constraints, setting upthe high-precision and high-quality analysis model of the fuel tank by taking shell unit asbasic unit by using HyperMesh software. Based on this model, the analysis and discussof static strength characteristics of the fuel tank are made, calculated the stressdistribution and deformation of fuel tank at the biggest stress conditions by using NXNastran solver, the results show that most of the fuel tank are smaller stress value, andthe maximum stress is less than the yield strength of material, strength allowance islarger. In addition, the article also had a fuel tank modal analysis to calculate the firstthree order natural frequency and corresponding modal type, verify the weak links of fueltank, analysis result indicates natural frequency of fuel tank having not avoided theoutstanding excitation frequency, would occur resonance phenomena, fing out the causeof the cracking of fuel tank. Finally, the cause for fracture of automotive fuel tankstructure was analyzed and improvement of the fuel tank structure was proposed andimplemented based on results of finite element analysis. The vibration durability test forthe improved fuel tank was implemented to verify effect of the fuel tank structureimprovement.Through the research of the paper, mastered the static characteristics and modalparameters of fuel tank, provides the theoretical references for design changes, getreasonable improvement scheme, using finite element analysis and test for verify effectof the fuel tank structure improvement. So, not only greatly reduces the automotive fueltank design cost also improve product.