Statistical Microbuckling Propagation Model for Compressive Strength Prediction of Fiber-Reinforced Composites

Compressive strength prediction for a fiber-reinforced composite material still remains an unresolved topic when dealing with composites in the design process. Although significant scatter is present in the experimental data, experimental test results are the only criteria on which to base design parameters. Although significant advances have been accomplished recently by various modeling techniques, only quantitative comparison with experimental data may be realized. This quantitative comparison requires the use of a semiempirical parameter into the model formulation, which is usually set as the fiber misalignment. By using a single value of the fiber misalignment within the composite~ model predictions easily match the experimental data because of the extreme sensitivity of the model with respect to fiber misalignment. However~ it is well known that there is not a unique value of fiber misalignment for all the fibers but rather a distribution of misalignments throughout the composite. In this paper, using the complete fiber misalignment distribution, stability theory is coupled with continuous damage mechanics to generate a model for compressive strength of continuous fiber-reinforced composites. Sample results are also presented showing the correlation of the analytical model with experimentally measured strengths.