Obtaining Fracture Properties by Virtual Testing and Molecular Dynamics Techniques
B. Farahmand, G.M. Odegard
TASS INC, US
Keywords: virtual testing, fracture allowable, molecular dynamics
Abstract:Fracture critical parts of aerospace structures must have adequate life to withstand the cyclic load environment throughout their service usage. The life analysis of these parts requires having fracture mechanics allowables that are obtainable through testing. These tests are costly and time consuming. Any method that can be used to minimize testing can be of great help to the program. The proposed technique can be extremely helpful to generate fracture toughness and crack growth data by using only the stress-strain curve for the material. Results of fracture data generated by this method have been verified by test results for numerous aerospace alloys and excellent agreement between analysis and test data were obtained. However, it was realized that in some cases, the full stress-strain curve does not exist in the literature and must be obtained through testing. For this reason and as an extension of this work, it is desirable to generate the full stress-strain curves by applying the multiscale modeling approach and therefore, making the above-mentioned technique free from testing. The application of the virtual testing methodology, together with the multiscale modeling will be useful to the aerospace industry where the cost and time of testing can significantly be reduced.