DESIGN STRENGTH DETERMINATION OF GFRP BY ACOUSTIC EMISSION TESTING

Mech. Design & Prod. Dept., Faculty of Engineering, Cairo University

  ABSTRACT

The knee in the acoustic emission cumulative counts curve has been proposed as a possible

solution to the absence of a characteristic yielding point in the stress-strain curve of composite

materials. Yield strength could eventually be adopted in the engineering design as an

alternative to the currently used maximum strength. A series of tensile type experiments have

been carried out for investigating the possibility of assessing this point for glass

fiber/polyester resin composites. Coupons with two stacking number of layers have been

examined under tensile experimental conditions. The derived value of the woven polyester

composites for their yield strength fall within reasonable range of 35-40% with respect to

their maximum strength.