naa a22 4500 510822614 CHVBK 20180411083541.0 cr unu---uuuuu 180411e20130901xx s 000 0 eng 10.1007/s12541-013-0206-8 doi (NATIONALLICENCE)springer-10.1007/s12541-013-0206-8 Study on twisting and bowing of roll formed products made of high strength steel [Elektronische Daten] [Wan-gi Cha, Naksoo Kim] Steel has been developed to have higher strength than ever before, especially for use of the lightweight structures of automobile. It needs to confirm spring back defects of cold roll forming of high strength steel, in which a sheet metal strip is gradually and successively bent into a desired profile. We developed a numerical analysis program based on the elastic-plastic finite element method to simulate roll forming of arbitrary cross sections. We applied augmented Lagrangian technique to solve contact problem between rolls and strip. Cross sections with different flange heights passing through three passes of roll stands have been experimented. The amounts of twisting and bowing occurred after roll forming were measured for both products made of mild steel and high strength steel, respectively. The performance of the developed FEA tool has been verified with measurements in terms of accuracy. The product of high strength steel showed more degrees of twisting and bowing than those of mild steel. We proposed a method to reduce the defects by compressing the web in thickness direction. It is confirmed using the verified FEA tool that the proposed method can reduce twisting and bowing of roll formed products significantly. Korean Society for Precision Engineering and Springer-Verlag Berlin Heidelberg, 2013 Elastic-plastic FEM nationallicence Roll forming nationallicence Twisting nationallicence Bowing nationallicence High strength steel nationallicence Cha Wan-gi Department of Mechanical Engineering, Sogang University, 35 Baekbeom-ro, Mapo-gu, 121-742, Seoul, South Korea aut Kim Naksoo Department of Mechanical Engineering, Sogang University, 35 Baekbeom-ro, Mapo-gu, 121-742, Seoul, South Korea aut International Journal of Precision Engineering and Manufacturing Springer Berlin Heidelberg 14/9(2013-09-01), 1527-1533 2234-7593 14:9<1527 2013 14 12541 https://doi.org/10.1007/s12541-013-0206-8 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s12541-013-0206-8 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Cha Wan-gi Department of Mechanical Engineering, Sogang University, 35 Baekbeom-ro, Mapo-gu, 121-742, Seoul, South Korea aut NATIONALLICENCE 700 1- Kim Naksoo Department of Mechanical Engineering, Sogang University, 35 Baekbeom-ro, Mapo-gu, 121-742, Seoul, South Korea aut NATIONALLICENCE 773 0- International Journal of Precision Engineering and Manufacturing Springer Berlin Heidelberg 14/9(2013-09-01), 1527-1533 2234-7593 14:9<1527 2013 14 12541 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer