+ Visit NASA.gov + Contact NASA   + Home Collection > NASA  Author > Richards, W. Lance  Author > Yeh, Hsien-Yang  NASA Center > Dryden Flight Research Center  Publication Year > 1991-2000 > 1997  Subject > A-C > Composite Materials  Availability Options > Online > PDF  Item/Media Type > NASA Report > Technical Memorandum (TM)  Item/Media Type > Technical Report  Note: Start a new navigation search by selecting a link above     Previous Record | Next Record + Back to Results   + Printer Friendly Title: Failure Study of Composite Materials by the Yeh-Stratton Criterion Author(s): Yeh, Hsien-Yang; Richards, W. Lance Abstract: The newly developed Yeh-Stratton (Y-S) Strength Criterion was used to study the failure of composite materials with central holes and normal cracks. To evaluate the interaction parameters for the Y-S failure theory, it is necessary to perform several biaxial loading tests. However, it is indisputable that the inhomogeneous and anisotropic nature of composite materials have made their own contribution to the complication of the biaxial testing problem. To avoid the difficulties of performing many biaxial tests and still consider the effects of the interaction term in the Y-S Criterion, a simple modification of the Y-S Criterion was developed. The preliminary predictions by the modified Y-S Criterion were relatively conservative compared to the testing data. Thus, the modified Y-S Criterion could be used as a design tool. To further understand the composite failure problem, an investigation of the damage zone in front of the crack tip coupled with the Y-S Criterion is imperative. NASA Center: Dryden Flight Research Center Publication Date: Oct. 1997 Document Source: CASI Online Source: View PDF File Document ID: 19970032100 Accession ID: 97N29149 Publication Information: Number of Pages = 8 Report Number: H-2201; NAS 1.15:113087; NASA-TM-113087 Contract-Grant-Task Number: NCC4-107 Price Code: A02 Keywords: COMPOSITE MATERIALS; CRACKS; CRITERIA; STRESS CONCENTRATION; HOLES (MECHANICS); RESEARCH; CRACK TIPS; CRACKING (FRACTURING); HOLE GEOMETRY (MECHANICS); STRUCTURAL FAILURE; FAILURE ANALYSIS; LOAD TESTS; Accessibility: Unclassified; No Copyright; Unlimited; Publicly available; Updated/Added to NTRS: 2005-08-25 + Back to Top + Sponsored by the NASA Scientific and Technical    Information Program + 2004 Vision for Space Exploration + Freedom of Information Act + NASA Web Privacy Policy and Important Notices + NASA Disclaimers, Copyright Notice,    and Terms and Conditions of Use NASA Official: Calvin Mackey Page Curator: NASA Center for AeroSpace Information (help@sti.nasa.gov) Last Updated: July 5, 2007