Failure Behavior of a Glass-fiber Reinforced Thermoplastic Composite

In this work, experiments were conducted to stamp form glass-fiber reinforced thermoplastics with different widths of hour-glass shapes. A forming limit diagram (FLD) is established based on the experimental data for this material, depicting strain forming limits at different deformation modes. The material system involved in the study is a glass-fiber reinforced polypropylene composite (TWINTEX (R)) with a fiber orientation of 0 degrees/90 degrees along the warp and weft directions. In this study, the conventional FLD method is adapted to use on thermoplastic composites and it is found that the major principle strain limit is the highest when the strain ratio is around - 0.5.