Tolerance Analysis With General Distribution Dimension And Its Application In Body Fit

Tolerance is very important for both quality and cost. The thesis is focused on complicated car body dimensional system management and body fit variation control through assembly tolerance analysis between design and manufacture process. Tolerance analysis theories and applications for car body are studied.With the introduction of car body manufacture techniques and quality control methods, a quality control system based on quality duty card is built up. Feature based tolerance analysis model used for body assembly and its two arithmetics: Monte Carlo simulation and linearized method are presented.Assembling process is simulated by the mean of computer aided tolerancing. Calculation precision and speed between Monte Carlo simulation and linearized method is compared through two cases, and the result shows advantages of linearized method. Following body assembly tolerance analysis software: Body Build Advisor is introduced.Aimed at general distribution dimension widely existed, non-normal distribution and mean shift for instance, an arithmetic based on root sum square is brought forward. Feasibility of this method is proved by some general distribution dimension cases.A sideframe-doors system is studied at last. Variation and mean shift of each measure functional dimensions is analyzed by sensitivity matrix. As a result, body fit quality is improved by assembly scheme optimization.