Mixed-Mode Failure Analysis of a Unidirectional Carbon/EpoxyComposite and Ahesively Bonded Composite Systems Using the Modified Losipescu Test Method

使用改进的 Losipescu 测试方法对单向碳/环氧树脂复合材料和粘合复合材料系统进行混合模式失效分析

• 批准号: 9102763
• 负责人: Maciej Kumosa
• 金额: $ 12万
• 依托单位: Oregon Graduate Institute of Science & Technology
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 1991
• 资助国家: 美国
• 起止时间: 1991-07-01 至 1993-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9102763&HistoricalAwards=false
• 关键词: Mixed; Mode; Failure; Analysis; Unidirectional

Research will be conducted to investigate mixed mode fracture mechanisms of a unidirectional carbon/epoxy composite material using the modified Iosipescu test technique. Intralaminar fracture mechanisms in the composite will be analyzed numerically and experimentally. The research will use finite element methods extensively to study the mixed mode stress intensity factors and the energy release rates associated with intralaminar cracks in the composite Iosipescu specimens tested under biaxial stress conditions. In addition, adhesively bonded composite systems will be tested under mixed mode loading conditions using the newly designed Iosipescu fixture. Linear and non-linear finite element calculations of the adhesive joints in the Iosipescu specimens will be performed. The fundamental significance of this research is that it will contribute to the understanding of intralaminar fracture mechanisms in carbon fibre/epoxy composites caused by biaxial stress conditions. Moreover, the study will provide new insights into the complex failure phenomena of advanced adhesive joint systems. The practical significance is that after comprehensive numerical and experimental investigations of the newly designed biaxial test technique, the test will have great potential to become standard for mixed mode failure and fracture analysis of many advanced composite systems.

采用改进的Iosiescu试验技术对单向碳/环氧复合材料的复合型断裂机理进行研究。对复合材料的层间断裂机理进行了数值分析和实验研究。这项研究将广泛使用有限元方法来研究在双轴应力条件下测试的复合材料Iosiescu试件中与层内裂纹相关的混合型应力强度因子和能量释放率。此外，粘接复合材料系统将使用新设计的Iosiescu夹具在混合模式加载条件下进行测试。将对Iosiescu试件中的粘接接头进行线性和非线性有限元计算。本研究的基本意义在于有助于理解碳纤维/环氧复合材料在双轴应力条件下的层内断裂机理。此外，这项研究将为先进胶接系统的复杂失效现象提供新的见解。其现实意义在于，通过对新设计的双轴试验技术进行全面的数值和实验研究，该试验将有很大潜力成为许多先进复合材料系统的混合模式破坏和断裂分析的标准。