Crushing Simulation Of Thin-walled Tube Based On Gradient Intension With Induction Heating

As a kind of common anti-collision structure in autobody,thin-wall tube has advantage in energy absorption and pressure stability.It can satisfy the security requirement and realize the lightweight design at the same time,which makes it popular in front impact.The structure improvement of thin-wall tube is always a key point in research among the researchers.By means of the mobile induction heating,this paper controlled the heating temperature of each part of the 20# thin-wall tube and cooled it down entirely and rapidly to prepare the controllable gradient intension tube.Studied the influence of intension distribution on deform pattern,load and energy absorption of the tube by the method of crushing simulation.Built the temperature–controllable mobile induction heating finite element model,got the temperature distribution of the heated tube.Based on the temperature distribution,carried out some heating experiments under different heating temperatures on gleeble machine.Conducted the uniaxial tensile experiment to get the stress-strain curve of the materials under different heating temperatures in order to get the intension distribution of the tube.Did the mobile induction heating experiment under the same heating condition as the simulation to prepare the gradient intension tube.Based on the stress-strain curve carried out the quasi-static simulation of the gradient intension tube.Finished the quasi-static experiment of the gradient intension tube and compare the fold number,deform pattern and the load-displacement curve of both to verify the accuracy of the simulation.Raised the concept of platform percent,intension slope and platform intension about the gradient intension tube and studied the influence of them on the tube deform pattern in quasi-static crushing simulation.The result shows that with the increase of platform percent,the tube nonaxisymmetry fold number reduce in the first and thenrise up.With the ascend of intension slope,the vary degree of the tube nonaxisymmetry fold number come down.With the increase of platform intension,the tube nonaxisymmetry fold number goes up until gets its top and in dynamic crushing simulation,the fourth fold needs less platform intension to get nonaxisymmetry deformation.Studied the influence of platform percent(P)and platform intension(S)on the load and energy absorption of the tube.The result shows that in quasi-static crushing simulation,the tube whose platform percent is 50% or platform intension is 803 Mpa has the most energy absorption and low load peak value.And in dynamic simulation,with the increase of specific energy absorption,the load peak value rises up,too.This paper gives a kind of example of the preparation of controllable gradient intension tube,and afford the reference for further study of the deform mechanism and intension distribution optimization.