DIRECT NUMERICAL-SIMULATION OF THE EXTENSION OF STRESS-CORROSION CRACKS IN GLASS-FIBERS EMBEDDED IN LAMINATES IN ACID ENVIRONMENTS

For glass-fiber-reinforced plastics in acid environments, previous work has generally concentrated on the propagation mechanisms and the propagation rate of a macroscopic stress-corrosion crack. In the present work, the extension of pre-existing microcracks on the surface of glass fibers embedded in laminates under acid solution has been investigated by means of a numerical simulation. The stress intensity factors along the front of a stress-corrosion crack have been calculated by using the three-dimensional boundary-element method. On the basis of the stress intensity factor and the reaction equation of glass to acid, the present work has studied the extension rate of the crack front. The simulated extension of the stress-corrosion crack in the glass fiber shows good correspondence with experimental results on fracture surfaces revealed by scanning electron microscopy.