Failure Processes in Fiber-Reinforced Liquid-Crystalline Polyester Composites |
| |
Authors: | T Weng A Hiltner E Baer |
| |
Institution: | Department of Macromolecular Science , Case Institute of Technology Case Western Reserve University , Cleveland, Ohio, 44106 |
| |
Abstract: | A hierarchical structural model for liquid-crystalline polyester reinforced with short glass fibers has been determined by using injection-molded bars. The gradient structure showed similar orientations between the glass fibers and the molecular orientation of the matrix. In the fiber-reinforced composites, the core failed prior to the skin by matrix cracking and transverse fiber pull-out as evidenced by the initial growth of parabolic cracks in the core. In the 30 wt% composite this was followed by complex cooperative phenomena involving fiber breakage, debonding, pull-out, and matrix deformation in the skin. The 50 wt% composite failed prematurely due to inadequate fiber/matrix interactions in the skin structure. Acoustic emission coupled with microscopy provided mechanistic insight throughout this work into the amount and intensity of specific failure mechanisms. |
| |
Keywords: | |
|
|