Study On The Energy Absorption Capability Of Shear Thickening Fluid And Applications To Vehicle Crash Protection

Shear thickening fluid(STF)is a kind of functional material,with lots of advantages such as quick response,good reversibility and high energy dissipation efficiency.In this paper,the shock resistance of the STF-filled crash cans of anti-collision beam is systematically studied by numerical simulation and experiment method with the hope of improving the low speed crashworthiness of vehicle.The primary coverage of this paper are presented below.Four different weight fraction of STF samples are prepared,whose steady state rheological property are tested.The result show that all four samples have three typical rheological properties: shear thinning,shear thickening and shear thinning.The buffer performance of STF is investigated by low speed drop bar impact test and the peak value of acceleration,the peak value of impact force and the energy absorption are taken as evaluation indicators.It is found that STF shows excellent energy dissipation characteristic.Also,the buffer performance of STF is studied by numerical method using LS-DYNA.The simulation result and test result show good agreement,which shows that the material model of STF is correct and lay a solid foundation for follow-up study.Numerical simulation are carried out to study the axial crushing behaviors of STF-filled thin-walled tube with different cross section shape.It is found that,STF filling can comprehensively improve the energy absorption abilities of thin-walled tube.This paper designs a kind of anti-collision beam system with a simple rectangular cross section of beam and six tube within it.Three kinds of anti-collision beam system are studied and there are STF-filled crash cans of anti-collision beam system,non-filled crash cans of anti-collision beam system and aluminum foam-filled crash cans of anti-collision beam system.The crashworthiness of all three kinds of anti-collision beam system under the 100% overlap rigid wall frontal impact and centre pole impact with 8km/h impact speed are studied by numerical simulation.The peak value of car body's acceleration,the peak value of impact force and the efficiency of the waveform are taken as evaluation index.Comparative study shows that the STF-filled crash cans of anti-collision beam system is more safety under low speed impact.The low speed impact energy absorption characteristics of STF-filled crash cans is studied by low speed drop hammer impact test.The evaluation index of energy absorption characteristics are collapse displacement,the peak value of impact force,the energy absorption efficiency and mean crushing load.It is found that,the energy absorption characteristics of STF-filled crash cans have been obviously improved,especially in reducing the peak value of impact force and increasing the energy absorption efficiency.