METHOD FOR EVALUATING DELAMINATION STRENGTH OF COMPOSITE MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide a method for evaluating delamination strength of a composite material formed by laminating FRP layers in such a manner that fiber orientation angles differ among the FRP layers.;SOLUTION: In order to evaluate an FRP delamination strength of a composite material formed by sequentially laminating FRP layers, an analytic model of the composite material based on a fiber orientation angle of each FRP layer is made, and stress analysis is performed using the analytic model to locate a position where delamination develops between the FRP layers of the composite material. An initial defect of a prescribed size is introduced to the position, analysis is performed with a virtual crack closing technique using the analytic model to obtain a relationship between a load and an energy release rate. A double cantilever test piece with the fiber orientation angle between delaminated FRP layers obtained by the stress analysis is prepared. A fracture toughness value of the test piece is measured, and on the basis of the obtained fracture toughness value, the delamination strength of the composite material is evaluated by referring to the obtained relationship between the load and the energy release rate.;COPYRIGHT: (C)2013,JPO&INPIT