Accurate analysis and thickness optimization of tailor rolled blanks based on isogeometric analysis

Combined isogeometric analysis (IGA) and shape optimization, this paper provides a method that can accurately analyze Tailor Rolled Blanks (TRB) and optimize its thickness profile continuously. While existed traditional methods can hardly solve these problems. TRB has a continuous transition between the thick and thin and a better surface quality. We found in IGA, two-dimension NURBS could present TRB geometry model exactly, but Kirchhoff shell element whose control points are allocated different thicknesses could not simulate TRB effectively. So, this paper uses three-dimension NURBS element to exactly present and accurately analyze TRB. It could avoid error caused by inaccurate presentation of geometry model and decrease error caused by solution field (displacement) approximation in numerical computation. Meanwhile, the positions of control points are taken as design variables in process of optimizing thickness profile. It can avoid the appearance of "unrealistic" shape and save lots of time spent in traditional tediously mesh updating as well as having better accuracy. This method makes accurate analysis and continuous thickness optimization of TRB become possible. It pushes the development of TRB engineering and extends the applications of IGA optimization. Several examples including benchmarks and application used the proposed method verified its effectivity, reliability and efficiency.