The effects of defects on the compressive response of thick carbon composites: An experimental and computational study

作者：Davidson Paul; Waas Anthony M^*

来源：Composite Structures, 2017, 176: 582-596.

DOI：10.1016/j.compstruct.2017.05.046

• Composite compression
• Defects
• Kink failure
• Wavy composite

The effects of defects on lowering the compressive strength of thick unidirectional carbon fiber polymer matrix composites are reported here. Experimental results on specimens with specially designed defect shape and sizes are presented. A decrease in compressive strength is seen with an increase in both misalignment angle and defect height. Defect aspect ratio seems to influence the dominant mode of failure, with lower defect aspect ratio coupons showing propensity to kink, whereas, higher aspect ratio defects showing propensity to split. However, there is no clear demarcation between the two modes or sequence of failure that can be inferred from the test results. To study the interaction and influence of defect dimensions on the compressive strength, a finite element based mechanics model is implemented. The model allows for kinking and splitting of composite layers. This study shows that compressive strength is dependent not only on the geometry of defects but also on the consolidation of plies over the defect. Furthermore, the need to have a mechanism based notion of compressive strength is borne out of the test results and model predictions.

• 出版日期2017-9-15