Heat Transfer And Numerical Simulation Research Of Fused Deposition Modeling Process

Fused deposition modeling is a kind of important rapid prototyping manufacturing technology that developed in recent decades and widely used in aerospace, automobile, electronics, medical treatment, construction, and so on. However, the development of this modeling technology is limited by the precision and quality of molding parts, and the precision and quality of molding parts is affected by heat transfer. Therefore, the heat transfer of printing nozzle, molding chamber flow field and molding part in fused deposition modeling process have been researched thoroughly by finite element analysis software ANSYS and FLUENT in this paper. The temperature field, thermal stress and strain field and flow field have been simulated. It not only has important theoretical significance, but also has important practical value on engineering.First of all, the heat transfer model of printing nozzle was established, and the temperature field and thermal stress strain field of nozzle was simulated. The results show that the upper and lower of nozzle has obvious temperature difference, the thermal deformation is mainly concentrated in the lower part of nozzle, and the thermal deformation will influence the quality and precision of molding parts.Secondly, the flow field model of molding chamber was established. The flow field of molding chamber in fused deposition modeling process was numerical analyzed by the method of computational fluid dynamics. The fluid temperature field, pressure field and velocity field of molding chamber were simulated. The results show that the flow temperature of the upper of molding chamber workbench is higher, the flow pressure near the molding chamber workbench is smaller, the flow velocity of left and right sides of molding chamber is larger, the flow temperature curves and flow pressure curves near the workbench appear to reverse the changing law, the flow temperature curves and flow velocity curves near the workbench show the same changing law.Then, the models of cooling process and forming process were established, and the temperature field in cooling process and thermal stress strain field after molding of molding parts were simulated. The results show that the temperature field in cooling process of molding part is not evenly distributed as a whole, the cooling of temperature on the surface of molding part is faster than that of heart, the equivalent stress and total displacement after molding of molding part are not evenly distributed as a whole, the thermal stress is concentrated in the middle of molding part, and the total displacement in the middle of molding part is larger.Finally, the fused deposition modeling temperature measurement experiment scheme was designed independently and the thermocouple temperature acquisition program was wrote independently. The simulated temperature and measured temperature of the surface of modeling specimen in cooling process was compared. The comparison results show that the numerical simulation of heat transfer during fused deposition modeling process is accurate and effective.