Life Prediction Methodology for Composite Laminates. Part 1. Constant Amplitude and Two-Stress Level Fatigue.
Abstract
A strength-based wearout model is presented for predicting the residual strength and life of composite laminates subjected to constant amplitude or two-stress level fatigue loadings. It is assumed that the laminate undergoes proportional loading, that its residual strength is a monotonically decreasing function of the number of loading cycles, and that the probability of failure after an arbitrary number of cycles may be represented by a two parameter Weibull function. The model also incorporates a "cycle mix factor" to account for the degradation of strength and life that may be associated with frequent changes in the stress amplitude of the loading. Experimental results from two-stress level loadings are used to evaluate the model's predictive capability for sequencing effects, as in a low-high or high-low test, and for cycle mix effects, as in a low-high-low-high repeating test. Good correlation between theory and experiment is obtained for all loadings and laminates studied.
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 01, 1994
- Accession Number
- ADA288343
Entities
People
- Barry D. Davidson
- Jeffery R. Schaff
Organizations
- Wright Laboratory