The Research On Numerical Simulation Technology Of The Forming Process Of Backlite

Backlite is one of the most important law parts of automobile,and its manufacturing requirement is quite strict while its forming process is fairly complex.So far,our understanding of this process still remains the empirical period,and actual manufacture mainly depends on trial and error.Therefore,it has practical significance and theoretical value to research on the process and to establish a set of relatively mature and accurate FEM simulation system.In this paper,an on-site survey about backlite's manufacturing process is firstly carried out.A correlation analysis between the various tooling molds and forming results is conducted,and a more scientific and reasonable procedure description about the backlite forming process under high temperature state is proposed.In order to accurately define the mechanical behavior of high-temperature glass,analysis and research on the microstructure characteristic and macroscopic temperature-sticky curve of the glass material is conducted,and by taking the actual industrial manufacturing process into considering,a conclusion that the high-temperature glass can be defined as a linear viscoelastic solid was put forward.A deep study and research is made on viscoelastic theory.And a proper form of constitutive equations is determined between differential form and integral form after analysis and comparison.Then,several typical differential constitutive equations of viscoelastic model is derived and compared.Finally,Burgers model is selected as the ideal model to describe the mechanical behavior of high-temperature glass.A survey on the experiments to obtain material parameters in viscoelastic constitutive equation of high-temperature glass is conducted.Found that it is full of challenges to perform creep experiment or relaxation experiment due to the special mechanical characteristics of high-temperature glass.A nano-indentation instrument may be the ultimate laboratory apparatus to perform this experiment.A large general commercial FEM software is used as the simulation platform in this research.A detailed instruction on what the algorithm of viscoelastic theory is like and how to define a viscoelastic material model is given.A set of creep experiment data is extracted from other publication and converted into the prony series format which is used in internal algorithm of ABAQUS.Finally a simulation analysis of the forming process is accomplished by simplifying the model,defining material property,selecting elements,meshing,defining contact pairs and applying loads.The simulation results qualitatively prove the validity of the research.