Modified Mode I Cohesive Traction-Separation Law for Z-Pinned Composite

Abstract

In this study a detailed numerical analysis is conducted to determine the traction-separation curve for z-pin under mode-I loading state. A single z-pin is modeled and studied with pre-stress and friction and cohesive interface modeled, to determine the traction-separation curves in mode-I. The results show that a traditional bi-linear or tri-linear traction separation curve is insufficient to capture the bending of z-pin and consequent frictional dissipation due to z-pin. Based on this a new approach to parameterize traction-separation is proposed.