Incremental Element-level Model Calibration and Verification of Composite Pi Joints

Abstract

A finite element modeling approach previously calibrated using experimental data from narrow element pi joints was extended to wide element joint specimens allowing for the assessment of predictive capabilities through comparisons to experimental data. The progressive failure modeling approach uses a novel cohesive formulation to include intra- and inter-laminar damage modes and their interactions. Properties defining the cohesive responses were calibrated at the narrow element level and subsequently used in the wide element model to establish blind predictions prior to experimental testing. Pi joint specimens were tested in pull-off loading. Experimental and numerical comparisons were made in terms of load-displacement response, critical loads, damage modes, and failure progression. Comparisons between the experimental results and blind predictions were found to be in good agreement overall. Following the initial comparisons, a recalibration effort was performed to improve correlation between experimental and numerical results.