Support-absorption composite clamping static response prediction and clamping deformation suppression

Abstract

Thin-walled spherical shells are weakly rigid and prone to clamping deformation under clamping force, which will affect machining accuracy. In this paper, the support-absorption composite clamping method is proposed and the in-situ conformal clamping strategy is obtained through the deformation coordination optimization. Firstly, the thin-walled spherical shell static response model is established, and the displacement analytic solution of equivalent constraint superposition is proposed by decoupling load and boundary constraint and Reisner's force-displacement hybrid method. Then, the vacuum generation of the Laval nozzle and pressure regulation mechanism is elucidated, and the matching mechanism of vacuum degree and spring support is revealed. Considering the support and adsorption deformation coordination optimization, the in-situ conformal clamping model is constructed. Next, the simulation explores the response of thin-walled spherical shells at different positions and adsorption effects on different wall thicknesses. The applied velocity ratio of the load in in-situ conformal clamping is analyzed. Finally, comparative experiments with different clamping methods are carried out and the results show that: Larger deformation in the top ± 10° range. The average prediction error of the theoretical model is 11.97%. With a larger load, the larger deformation, and recommended to control within 0.5Mpa. A larger number of partitions isn't recommended, nonlinearities could cause larger acceleration mutations. The thinner the thickness or the smaller the support load, the support-adsorption composite clamping effect is more obvious, the maximum can reduce the clamping deformation by 64.3%. In-situ conformal clamping method can reduce the deformation of the clamping process by 33.3%.