基于显著性的薄壁铝合金管小弯曲半径数控弯曲工艺参数优化_英文_.docxVIP

Trans. Nonferrous Met. Soc. China 22(2012) 147?156Significance-based optimization of processing parameters for thin-walledaluminum alloy tube NC bending with small bending radiusXU Jie, YANG He, LI Heng, ZHAN MeiState Key Laboratory of Solidification Processing, School of Materials Science and Engineering, Northwestern Polytechnical University, Xi’an 710072 ChinaReceived 24 December 2010; accepted 27 June 2011Abstract: Thin-walled aluminum alloy tube numerical control (NC) bending with small bending radius is a complex process withmulti-factor coupling effects and multi-die constraints. A significance-based optimization method of the parameters was proposed based on the finite element (FE) simulation, and the significance analysis of the processing parameters on the forming quality in terms of the maximum wall thinning ratio and the maximum cross section distortion degree was implemented using the fractional factorial design. The optimum value of the significant parameter, the clearance between the tube and the wiper die, was obtained, and the values of the other parameters, including the friction coefficients and the clearances between the tube and the dies, the mandrel extension length and the boost velocity were estimated. The results are applied to aluminum alloy tube NC bending d50 mm×1 mm×75 mm and d70 mm×1.5 mm×105 mm (initial tube outside diameter D0 × initial tube wall thickness t0 × bending radius R), and qualified tubes are produced.Key words: thin-walled aluminum alloy tube; optimization; finite element (FE); numerical control bending; processing parameters;significance analysis; small bending radiusplastic forming process of tube bending. TANG [2]developed some practical formulae to analyze plastic deformation in tube bending. The results explained tube bending phenomena well and provided an initial technical guide. However, multi-constraint actions by dies were not referred. NORMANI [3] established an analytic model to predict the str