Abstract
This thesis is on the carbon/epoxy composite plates containing a microcrack, which traps in water. When temperature is at freezing point, the volume of water will expand and cause stress concentration at the tip of the crack. The stresses at the different angle around the tip of crack are analyzed, and the condition that the temperature is below 0° Celsius is also considered. The simulation and analysis of this study have been done with ANSYS, and the stress intensity factors have been calculated by using the stress rounding factor. The results show that the longer crack causes the greater the stress. It is also found that the crack length affect more to stress field when fiber orientation in y direction. For the same crack size, the stress intensity factors are greater for the y-direction fiber than for z-direction fiber. The stress gradient near the tip of the crack descends more for y-direction fiber composites than for z-direction-fiber composites. When the temperature is below 0° Celsius, the stresses are far smaller than those at 0° Celsius. In the situation that the freezing ice is well contained in the composite plate, for the crack being near the edge of the plate, the stress increases dramatically. While the crack is near the center of the plate, the stress is slightly larger than that a edge-crack plate.