The optimum die profile for the cylindrical bending of plates

This paper presents a methodology for the design of plate-forming dies in cylindrical bending using optimization techniques to reduce the cost of die production by reducing the trial-and-error procedure considerably in determining the final die geometry. The plate thickness is discretized by plane-strain finite-elements. The die is taken to be rigid and its profile is approximated by Bezier curves the control-point coordinates of which are the design variables. The die profile is varied to minimize the difference between the required shape and the shape of the bent plate, considering springback action. The unconstrained optimization problem is solved by the BFGS (Broyden-Fletcher-Goldfarb-Shanno) method. A numerical example is presented where the optimum die profile is obtained for a plate bent into a quarter circle. (C) 1997 Elsevier Science S.A.


An exponential big bang-big crunch algorithm for discrete design optimization of steel frames
Hasançebi, Oğuzhan (2012-11-01)
In the present study an enhanced variant of the big bang-big crunch (BB-BC) technique, namely exponential BB-BC algorithm (EBB-BC) is developed for code based design optimization of steel frame structures. It is shown that the standard version of the BB-BC algorithm is sometimes unable to produce reasonable solutions to problems from discrete design optimization of steel frames. Hence, through investigating the shortcomings of BB-BC algorithm, it is aimed to reinforce the performance of the technique for th...
The stability of linear periodic Hamiltonian systems on time scales
Zafer, Ağacık (2013-03-01)
In this work, we give a new stability criterion for planar periodic Hamiltonian systems, improving the results from the literature. The method is based on an application of the Floquet theory recently established in [J.J. DaCunha, J.M. Davis, A unified Floquet theory for discrete, continuous, and hybrid periodic linear systems, J. Differential Equations 251 (2011) 2987-3027], and the use of a new definition for a generalized zero. The results obtained not only unify the related continuous and discrete ones ...
A New Flicker Contribution Tracing Method Based on Individual Reactive Current Components of Multiple EAFs at PCC
Altintas, Erinc; Salor, Oezguel; ÇADIRCI, IŞIK; Ermiş, Muammer (2009-10-08)
In this paper, a new flicker contribution tracing method has been proposed to determine the individual flicker contributions of multiple electric arc furnace (EAF) loads to the flicker measured at the point of common coupling (PCC). The proposed method decouples the flicker contribution of the interconnected electricity system from the individual contributions of the loads connected to the measured PCC, using the individual current variations of the loads, and the estimated short-circuit system impedance. I...
The plastic and the ultimate resistance of four-bolt extended end-plate connections
Özkılıç, Yasin Onuralp; Topkaya, Cem (2021-06-01)
Widely used design guidelines and specifications provide methods to calculate plastic resistance of end-plates considering yield line mechanisms. Experiments reported to date showed that the ultimate resistance of end-plates can be considerably larger than its plastic resistance due to strain hardening. Using the ultimate strength in design can be a viable and cost-effective option; however, limited studies exist on quantifying the ultimate strength. In this paper, a database of four-bolt extended end-plate...
A robust algorithm for configurational-force-driven brittle crack propagation with R-adaptive mesh alignment
MIEHE, CHRISTIAN; Gürses, Ercan (2007-10-08)
The paper considers a variational formulation of brittle fracture in elastic solids and proposes a numerical implementation by a finite element method. On the theoretical side, we outline a consistent thermodynamic framework for crack propagation in an elastic solid. It is shown that both the elastic equilibrium response as well as the local crack evolution follow in a natural format by exploitation of a global Clausius-Planck inequality in the sense of Coleman's method. Here, the canonical direction of the...
Citation Formats
S. Oral and H. Darendeliler, “The optimum die profile for the cylindrical bending of plates,” JOURNAL OF MATERIALS PROCESSING TECHNOLOGY, pp. 151–155, 1997, Accessed: 00, 2020. [Online]. Available: