A new relaxation method for roll forming problems

Ding, S., Daniel, W. J. T. and Meehan, P. A. (2006). A new relaxation method for roll forming problems. In: J. A. C. Martins, H. C. Rodrigues, J. A. C. Ambrosio and et al., III European Conference on Computional Mechanics: Book of Abstracts. III European Conference on Computional Mechanics Solids, Structures and Coupled Problems in Engineering, Lisbon, Portugal, (536-536). 5-8 June 2006.


Author Ding, S.
Daniel, W. J. T.
Meehan, P. A.
Title of paper A new relaxation method for roll forming problems
Conference name III European Conference on Computional Mechanics Solids, Structures and Coupled Problems in Engineering
Conference location Lisbon, Portugal
Conference dates 5-8 June 2006
Proceedings title III European Conference on Computional Mechanics: Book of Abstracts
Place of Publication Amsterdam, The Netherlands
Publisher Springer
Publication Year 2006
DOI 10.1007/1-4020-5370-3_536
ISBN 978-1-4020-4994-1
978-1-4020-5370-2
Editor J. A. C. Martins
H. C. Rodrigues
J. A. C. Ambrosio
et al.
Start page 536
End page 536
Total pages 1
Language eng
Abstract/Summary Finite element analysis (FEA) of nonlinear problems in solid mechanics is a time consuming process, but it can deal rigorously with the problems of both geometric, contact and material nonlinearity that occur in roll forming. The simulation time limits the application of nonlinear FEA to these problems in industrial practice, so that most applications of nonlinear FEA are in theoretical studies and engineering consulting or troubleshooting. Instead, quick methods based on a global assumption of the deformed shape have been used by the roll-forming industry. These approaches are of limited accuracy. This paper proposes a new form-finding method - a relaxation method to solve the nonlinear problem of predicting the deformed shape due to plastic deformation in roll forming. This method involves applying a small perturbation to each discrete node in order to update the local displacement field, while minimizing plastic work. This is iteratively applied to update the positions of all nodes. As the method assumes a local displacement field, the strain and stress components at each node are calculated explicitly. Continued perturbation of nodes leads to optimisation of the displacement field. Another important feature of this paper is a new approach to consideration of strain history. For a stable and continuous process such as rolling and roll forming, the strain history of a point is represented spatially by the states at a row of nodes leading in the direction of rolling to the current one. Therefore the increment of the strain components and the work-increment of a point can be found without moving the object forward. Using this method we can find the solution for rolling or roll forming in just one step. This method is expected to be faster than commercial finite element packages by eliminating repeated solution of large sets of simultaneous equations and the need to update boundary conditions that represent the rolls.
Subjects E1
290501 Mechanical Engineering
670000 - Manufacturing
Q-Index Code E1

 
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Created: Thu, 23 Aug 2007, 21:59:35 EST