Study On Simulation And CAPP Expert System Of Forging Process For Large-Scale Module

Large-scale module is the blank which produces large-scale mould. The products of moulds are used for manufacture of various important part's blank, automobile's cover parts and shell of domestic electric appliance and so on. Its application is extensive in production. The large-scale module is difficult to manufacture, and waster rate is higher, and is suited to forge by LZ and NEW FM because its width height ratio is big. But the process parameter of the two forging methods need precise value to avoid generating two-direct tensile stress in the forgings body, and the relationship of the reasonable matching between anvil width ratio(AWR), blank width ratio(BWR) and compression ratio(CR) need further study. The forging process simulation and CAPP expert system are researched on large-scale module, which is of great significance to contribute to enrich and develop theories and technologies of forging process and design the forging process of large-scale module reasonable and automatically. Guided by the new forging theories and technologies, finite element software ANSYS is applied to simulate NEW FM and LZ based on systemic viewpoint. The influence of AWR, BWR and CR affecting the distribution of stress one another in the forgings bodies are analyzed. The process parameter is gained by control the effective center of forgings' compress stress can't meet the fact production. Therefore, the process parameter should be determined by control the compress stress at point M (0.25 times blank width distance center on transverse direct) and P (0.5 times anvil width distance center on axial direct). The critical AWR which makes axial tensile stress not existence and the critical BWR which makes transverse tensile stress not existence, and the reasonable and matching process parameter of AWR, BWR and CR is obtained based on above viewpoint for the forgings are practicability (or safety). The influence of stiff length affecting stress distribution under different AWR, BWR and CR when stretching by NEM FM were simulated and analyzed. The critical stiff length which makes axial and transverse tensile stress turn to zero at the center of forgings bodies under some definite AWR, BWR and CR is obtained. The NEW FM is simulated by physical method. The influence of BWR and stiff length affecting stress in the forgings bodies is analyzed. The zero thickness fissure is stimulated in the forgings bodies through fit clearance between hole and cylinder is negative or zero. The stress state at some point in forgings body is definite by checking it has fissure or not at the same point. Process knowledge expression, obtain, management technology, inference control strategy, explanation mechanism, and the application of they are used in CAPP system are introduced. Foundational thinking and key technology based on combination of rule and case, description based on parts feature using OO(Object Oriented) technology, and exploitation procedure of CAPP expert system leaded by prototype technology. The results of numerical simulation are extracted into process rules to establish a knowledge base. A process design expert system is developed on Windows platform with the object-oriented Delphi language. In this system, the technology based on rule combined case, description based on parts feature using OO technology, the knowledge expression of rule and frame representation combined using OO technology, forward direction inferring technology, depth priority searching strategy of and/or tree, and conflict solution strategy of priority rule which used frequently based on knowledge library recombination technology are used. The application used these technology make the software design easily and practicably.