Abstract
A model is presented for predicting the residual strength and life of composite laminates subjected to randomly ordered spectrum fatigue loadings. It is assumed that the laminates undergo proportional loading, that the residual strength is a monotonically decreasing function of the number of fatigue cycles, and that the probability of failure after an arbitrary number of cycles can be represented by a two parameter Weibull distribution. The model also incorporates a `cycle mix factor' which accounts for the drastic reduction of fatigue life that may be caused by a large number of changes in the stress amplitude of the loading. For uniaxially loaded laminates, the experimental data that is necessary to characterize the model consists of static tension and compression strengths, S-N curves based on constant amplitude fatigue life distributions for three stress ratios, and a limited amount of two-stress-level fatigue test results. The model is verified by comparing predicted fatigue life distributions to experimentally observed fatigue life data for angle-ply and quasi-isotropic graphite/epoxy laminates subjected to different tension and compression dominated FALSTAFF (Fighter Aircraft Loading STAndard For Fatigue) load spectrums. Very good correlation between experimentally observed and theoretically predicted fatigue life distributions is obtained for all laminates and loading spectrums studied.
| Original language | English (US) |
|---|---|
| Pages | 89-109 |
| Number of pages | 21 |
| State | Published - 1994 |
| Externally published | Yes |
| Event | Proceedings of the 1994 International Mechanical Engineering Congress and Exposition - Chicago, IL, USA Duration: Nov 6 1994 → Nov 11 1994 |
Other
| Other | Proceedings of the 1994 International Mechanical Engineering Congress and Exposition |
|---|---|
| City | Chicago, IL, USA |
| Period | 11/6/94 → 11/11/94 |
ASJC Scopus subject areas
- General Engineering