Measurement of the critical energy release fate G(IIC) for filament wound GRP pipes

An experimental procedure is described for measuring the critical energy re lease rate G(IIC) of filament wound pipes by making use of lateral indentat ion experiments on these pipes and correlating the dissipated energy to the delamination area. Factors that might influence the results of this proced ure are discussed. Two pipes of different nominal thicknesses have been tes ted and their critical energy release rates measured. The values obtained f rom different specimens of the same type show good consistency. The thinner pipes tend to produce a lower critical energy release rate. The measured v alues have been used as part of the input data in a numerical simulation of the problem of indentation of the pipes, which involves large deformations and extensive damage. Excellent agreement has been demonstrated between th e results and experimental data, which serves as a validation of the proced ure proposed for estimating the critical energy release rate. (C) 2001 Else vier Science Ltd. All rights reserved.