Simulation Of Thermomechanical Coupling In Polymer With Defect

Polymer are widely used in industry. They may become defected object because they appeared crack, cavity, small hole in the course of manufacture and usage. Energe dissipation of defected object have many forms in the course of breakage, including plastic deformation energy, surface energy of forming fracture and demage energy. Plastic deformation energy dissipated in the form of heat, then temperature field is formed in the local defected object. Moreover, the change of temperature field reflect the evolvement of defect in some extent. Therefore, nonlinear mechanical behaviour which consist of polymer deformation, fracture and time-depended is required to be studied. Thermomechanical coupling effect in the course of polymer's breakage is required to be studied. Moreover, macro breakage model of defect's evolvment and nonlinear rheology response equation is also required to be studied. These can assess polymer's durability and life and have important theoretic and applied value. These can also provide important theoritic basis for modification of polymer and composite material, application and high capability of polymer.At first, computation method of defected polymer's stress and strain is given in this paper by using elastic-plastic mechanics, damage mechanics, fracture mechanics. Polymer which have small fissure and small hole is analysed and simulated. The stress cloud map in different strength theory is drawn. By compararing simulation results with experimental results, the conclusion can be drawn that the forth strength theory is more fit with experimental results. These give the foundation of temperature field's computation.Then plastic zone near the polymer's Crack tip is analysed and the model is built. Plastic zones near Polymer with Crack tip which is small fissure and small hole are simulated and graph of plastic shear strain rate is drawn. The simulation results show that the shape of plastic zone near Polymer with Crack tip is between the second stress cloud map and Mises stress cloud map.At last the relation of deformation of polymer's Crack tip and energy conversion are analysed stress. The relation of plastic energy and elastic energy of polymer's Crack tip are stuied. Temperature field model in polymer's Crack tip is built by analysing property of polymer. The experimental equipments of temperature are constructed and temperature experiments of polymer's Crack tip are made. Heating effect of polymer's Crack tip is studied by observing and recording speciman's temperature throughout applying to load. Temperature field of polymer's Crack tip are simulated. Simulation results show the effectiveness and validity by comparing simulation results and experimental results.