Finite Element Simulation On The Temperature Field And Stress Field Of Compression Molding Of Optical Glass Lens

Optical glass lens are widely used for communication, measurement, imagingand manufacturing in industrial field. In recent years, with the requirements of marketincreasing for glass optical lens, compression molding which is the most advancedmanufacturing technology for optical lens has developed rapidly. This technology hashigh production efficiency and achieves mass production of optical glass lens. In thetechnology of compression molding, temperature has an important influence onforming of lens. stress is also a key indicator to the quality of the lens. both areclosely related to life of mould. It is difficult to measure inner temperature and stressof lens and mould by traditional methods, therefore, the heat transfer mechanism andstress history can not be understood. In order to provide a theoretical basis for processoptimization, temperature field and stress field of compression molding are simulatedby finite element method in this paper.Firstly, in the first chapter background and basic principles of compressionmolding are introduced, the finite element method and the research status of finiteelement simulation on glass lens molding are summarized, and the purpose of finiteelement simulation on this technology are proposed. In the second chapternonlinearity FEM are introduced, the basic theory and finite element solving of heattransfer are stated in detail.Secondly, based on MSC.Marc software axisymmetric simulation model ofuniaxial compression of cylindrical glass are established. In the calculation oftemperature field in the third chapter, the nonlinear relationship betweenthermodynamic parameters of glass and the temperature are defied into the materialproperties. It is believed that the rising of glass temperature is mainly because solidheat conduction from mould and convection heat transfer of nitrogen. In thecalculation of stress field in the fourth chapter, general maxwell viscoelastic stressmodel is used to describe the deformation behavior of glass at high temperatures, andthe friction effect between glass and mould is fully taken into account. In the analysisof the calculation results, the changing time histories of temperature field and stressfield within the cylinder glass is discussed, and the effects of friction coefficient onthe frictional force and the equivalent stress are studied.Finally, in the fifth chapter non-isothermal compression molding method of aspherical optical glass lens is introduced. On the premise that aspherical lens haveexellent optical performance, this method is proposed for the purpose of extendingservice life of mould and improveing productivity.In order to optimize technology, thecoupled thermo-mechanical analysis of finite element simulation is carried out, thecomparison between non-isothermal and isothermal molding is studied, and optimaltemperature match between glass and mold is obtained.