Application of unified fatigue damage approach to compression–tension region

✍ Scribed by A.K. Vasudevan; K. Sadananda

• Publisher: Elsevier Science
• Year: 1999
• Tongue: English
• Weight: 568 KB
• Volume: 21
• Category: Article
• ISSN: 0142-1123
• DOI: 10.1016/s0142-1123(99)00097-3

✦ Synopsis

A Unified Approach to fatigue crack growth developed earlier is extended to include the fatigue behavior over the entire load ratio (R) regime, from compression-tension to tension-tension. This approach provides a self consistent description of cyclic damage using the two loading parameters, ⌬K and K max , applicable over the entire crack growth regime. Crack growth behavior in the RϾ0 regime has been classified into five distinct classes. This classification is extended here to include the negative R-ratio region. When compression loads are included with the tension cycle, each classification is further divided into three additional subsets, reflecting a characteristic change in crack growth mechanisms. The current overall classification provides a methodology for understanding the combined effects of tension and compression loads on crack tip forces and their effect on material crack growth resistance. Like wise the role of environmental effect will also be altered in the presence of compressive forces.