Process optimization of tape placement for thermoplastic composites

Despite the advantages of tape placement with its high production rate in manufacturing composite laminates, residual stress development and operation under non-optimum conditions remain as the drawbacks to be surpassed. The goal of this study is to develop a process optimization scheme for tape placement. Two objectives of optimization are separately considered; one is to minimize the peak tensile residual stress. The other is to increase the productivity by maximizing the processing speed. Two quality requirements act as constraints in the optimization procedure. First of all, the chosen process parameters should be conducive to good bonding between the tape and substrate; secondly thermal degradation should not be excessive. In order to determine temperature distribution, residual stresses, bond quality, and thermal degradation, previously developed process models were used. Nelder-Mead, a zeroth-order search algorithm, was employed to minimize the objective function. The numerical results showed that significant improvement could be achieved through optimization and a laminate with acceptable quality could be produced in situ. (c) 2007 Elsevier Ltd. All rights reserved.