Uncertainty analysis and robust design optimization for the heat-assisted bending of high-strength titanium tube  

作　　者：ZHANG Zhao YANG JingChao HUANG WeiLiang MA Jun LI Heng 

机构地区：[1]Taicang Yangtze River Delta Research Institute,Northwestern Polytechnical University,Taicang 215400,China [2]State Key Laboratory of Solidification Processing,Northwestern Polytechnical University,Xi’an 710072,China

出　　处：《Science China(Technological Sciences)》2021年第10期2174-2185,共12页中国科学（技术科学英文版）

基　　金：supported by the National Natural Science Foundation of China(Grant No.51775441).

摘　　要：Heat-assisted rotary draw bending(HRDB)is a promising technique for manufacturing difficult-to-form tubular components comprising high-strength titanium tubes(HSTTs)with small bending radii.However,as a multidie constrained and thermomechanical coupled process with many uncertainty factors,a high risk of several defects,such as cross-section distortion,over wall thinning,or even cracking,is present.Achieving the robust design optimization(RDO)of complex forming processes remains a nontrivial and challenging scientific issue.Herein,considering a high-strength Ti-3Al-2.5V titanium alloy tube as a case material,the five significant uncertainty factors in HRDB,i.e.,temperature distribution,tube geometrical characteristics,tube material parameters,tube/tool friction,and boost velocity had been analyzed.Subsequently,considering the preheating and HRDB of HSTT,a whole-process thermomechanical three-dimensional finite element model was established and validated for virtual experiments.Further,considering the maximum section distortion Q and maximum wall-thickness thinning t as the optimization objectives and the mean and variance of material and forming parameters,an RDO model was established.Finally,the Pareto optimal solutions were obtained using the nondominated sorting genetic algorithm II,and a minimum distance selection method was employed to obtain the satisfactory solution.Results show that the optimized solutions considering the uncertainty factors reduce the maximum section distortion rate of HSTT after bending by 38.1%and the maximum wallthickness thinning rate by 27.8%.

关 键 词：robust design optimization uncertainty factors heat-assisted bending high-strength titanium tube 

分 类 号：TG306[金属学及工艺—金属压力加工]