Finite Element Analysis And Optimization Of Extrusion Component In Vacuum-extruder

The vacuum-extruder is the key mechanical equipment in building brick and tile wall materials products such as plastic extrusion. The quality of mud segment in the vacuum-extruder influences the quality of the shaping base directly. At present extrusion process theory research of the vacuum-extruder still immature, and development is slow, which lead to many problems in the design and manufacturing of the vacuum-extruder. Many product defects frequently appeared in extrusion region of the below grade of vacuum-extruder, such as breakage on screw, crack defect on shaping base in head and die for vacuum-extruder. These problems are severely restricts the use and promotion of the vaccum-extruder, then affects the development of brick and tile industry. So it is necessary to make a specialized research and analysis for the extrusion machine components that influence the extrusion quality of the mud materials, such as screw, head and die for vacuum-extruder. And this can provide a theory basis and optimization scheme for vacuum-extruder design and improvement.Based on the model JKY95-65/60 vacuum-extruder, this dissertation researched the pressure field of the extrusion region synthetically applying of material rheology, measure technology, finite element method, calculate fluid dynamic and optimization and so forth theories and methods, and then made an analysis of the screw according to the results of the study, and made an fluid analysis of the head and die of vacuum-extruder which connected the extrusion region at last. The main study contents include:(1) The mud rheological model was studied, and the geometric model of the mud in extrusion region of the vacuum-extruder was modeled with APDL. Based on these, the boundary conditions were loaded on the finite element model of the fluid field in the extrusion region, the pressure distribution was simulated in the Flotran module. The study revealed the movement mechanism of the mud during the process of extrusion, obtained the distribution of the pressure of mud, which provides a reference for the finite element analysis of screw in the next step.(2) By means of loading the pressure distribution and corresponding restrains on the finite model of the screw in the Workbench, the deformation, von-Mises equivalent stress and shear stress of the screw was obtained, that reveals the reason of the defects on the screw. Through shape improve, one optimal screw model was got, which meets the safety requirements in the operation.(3) The head and die of the vacuum-extruder is modeled in the Pro/E and imported the CFX module of the Workbench to simulate the velocity distribution. The velocity distribution of the export section of the die of the vacuum-extruder reveals the main cause of defects on the shaping base, and then optimize the design of the model according this. Through size optimization, the relationship between the size of the head of the vacuum-extruder and the velocity of the export section on the die of the vacuum-extruder obtained, and then reached an optimal size on condition that minimize the velocity difference on the export section using the goal drive optimization design. The surface pressure distribution of the flow field obtained at last, and this can provide some guidance for the design of thickness of the model.