Stochastic estimation of the number of fiber-break points in a CFRP by Markov process

Abstract

A stochastic model based on Markov process is proposed to estimate the number of fiber-break points of a unidirectional fiber-reinforced composite. This model relies on the assumption that each state is assigned in the order of the fiber-break point number, and that it transits to two states from one state. The first state of the two is a state causing a composite fracture, and another is a state of survival while being damaged. Mini composites with 2–4 fibers were prepared using carbon fiber and epoxy resin to examine the applicability of the model. Predicted failure probability curves approach experimentally obtained data with an increase in the fiber-break point and ultimately agree with them. The fiber-break points till fracture are estimated with greater numbers than the number of fibers, which elucidates the significance of the experimental results higher than the average fiber strength. The validity of the model was finally discussed while considering the stress concentration around fiber-break point(s).

Keywords:

• Cumulative fiber-breaks
• Mini composites
• Carbon fiber
• Tensile strength
• Weibull distribution
• Stochastic process

Disclosure statement

No potential conflict of interest was reported by the authors.