Investigation On Dynamic Behavior Of AHSS Curved Panel Under Thermal-mechanical Coupling

Due to its high deformation resistance,high strength and good welding performance,advanced high strength steel(AHSS)is more and more popular in the automotive industry.It is mainly used to manufacture structural parts and safety parts of automobiles.Reasonably adopting AHSS can effectively reduce the weight of the vehicle body while improving the passive safety and the price/performance ratio of the vehicle.This paper investigates AHSS panel’s temperature field under thermal load,mechanical performance under impact load,thermoelastic dynamic response under laser processing and thermoelastic dynamic behavior under periodic loading by taking AHSS plate as the research object and combining different external load conditions and different internal structure and material characteristics.The main research contents of this paper are(1)This paper firstly proposes an analytical solution for one-dimensional transient heat conduction problem,based on non-Fourier heat conduction law and the Fourier,for a coated AHSS panel.The influences of thermal relaxation time,temperature boundary conditions and coating parameters on temperature increment distribution of the coated AHSS plate are also studied.(2)A set of nonlinear governing equations for an AHSS doubly curved panel subjected to low velocity impact,based on classical von Karman equation and thin shell theory,is deduced,and these equations can be solved by using the finite difference method and the Newmark method.Numerical results show that the panel’s geometrical parameters,material properties and the impactor’s parameters have great influences on the non-dimensional deflection,non-dimensional normal stress and non-dimensional contact force.(3)Three-dimensional transient temperature function for a multi-layer AHSS doubly curved panel under laser processing is firstly obtained,based on separation of variables method.Subsequently,the thermal and dynamic governing equations can be solved through numerical metnod of finite difference and the Newmark.Numerical results reveal that coating’s heat conduction coefficient,laser power and moving velocity and the panel’s geometric parametershave great influence on non-dimensional displacement and normal stress.(4)Three-dimensional transient temperature function for a single-coated AHSS doubly curved panel under periodic loading is firstly obtained,based on separation of variables method.Subsequently,the thermal and dynamic governing equations can be solved through numerical metnod of finite difference and the Newmark.Numerical results present that the amplitude of mechanical load,the period of mechanical load,the area of thermal load and the panel’s geometric parameters have great influence on non-dimensional displacement and normal stress.The process and results of this paper extends and develops the related theory of AHSS structures,provides a certain basis for further theoretical or experimental research on the thermodynamic behavior of AHSS structure,and it can guide the engineers to carry out the application and designing of AHSS structure.