Study On Tolerance Analysis Model Based On Convex Hull

With the development of social productive forces, the appearance and quality of the product become more important for people. High-performance, high-quality appearance of the product requirements, along with that of the product replacement rate are becoming more and more important. While tolerance analysis plays a more important role in the work, tolerance analysis is a bond to contact the production and design. At this stage, three-dimensional tolerance analysis for the research work is still at an early stage in the product design process, some products still rely on dimensional tolerance design experience to complete. Based on the new generation of GPS, the tolerance model based on convex hull, the optimized stack-up model based on datum flow chain and the modified Monte Carlo method are constructed to the work of tolerance analysis. The feasibility and accuracy are verified by using the software of 3DCS. The main contents are as follows:(1) Literature studies on computer aided tolerance and GPS standard system are carried out.(2) The tolerance representation model based on tolerance zone and the basis for tolerance modeling based on convex hull are constructed through literature studies on the SDT theory, the form of tolerance zone and the tolerance principle.(3) The tolerance model based on convex hull is completed including some common features and some common tolerances.(4) The PDF of features in the tolerance zone is established by the analysis of some common assembly (pin-hole, tab-slot). The Monte Carlo method for simulation is optimized.(5) The theory proposed in this paper is not only verified through a vehicle body sub-assembly, but also made a comparison with the software of 3DCS. At last, the feasibility and precision is proved.