Micro-mechanical finite element analysis of Z-pins under mixed-mode loading. (November 2015)

• Record Type: Journal Article
• Authors: Zhang, B.; Allegri, G.; Yasaee, M.; Hallett, S.R.
• Is Part Of: Composites. Volume 78(2015)
• Page Start: 424
• Page End: 435
• Publication Date: 2015-11
• Subjects: B. Delamination -- B. Mechanical properties -- C. Finite element analysis (FEA) -- Z-pinning; Composite materials -- Periodicals; Manufacturing processes -- Periodicals; Composite materials; Manufacturing processes; Periodicals; 620.11805
• DOI: 10.1016/j.compositesa.2015.07.006
• Languages: English
• ISSNs: 1359-835X

Abstract

Abstract: This paper presents a three-dimensional micro-mechanical finite element (FE) modelling strategy for predicting the mixed-mode response of single Z-pins inserted in a composite laminate. The modelling approach is based upon a versatile ply-level mesh, which takes into account the significant micro-mechanical features of Z-pinned laminates. The effect of post-cure cool down is also considered in the approach. The Z-pin/laminate interface is modelled by cohesive elements and frictional contact. The progressive failure of the Z-pin is simulated considering shear-driven internal splitting, accounted for using cohesive elements, and tensile fibre failure, modelled using the Weibull's criterion. The simulation strategy is calibrated and validated via experimental tests performed on single carbon/BMI Z-pins inserted in quasi-isotropic laminate. The effects of the bonding and friction at the Z-pin/laminate interface and the internal Z-pin splitting are discussed. The primary aim is to develop a robust numerical tool and guidelines for designing Z-pins with optimal bridging behaviour.