Modified Lap Shear Test for Automated Fiber Placement (AFP) of Steered Thermoplastic Composite Tape

Abstract

Manufacturing of Variable Angle Tow (VAT) laminates by in-situ consolidation of thermoplastic composite tapes using Automated Fiber Placement (AFP) or Automated Tape Laying (ATL) techniques has gained recent popularity due to its ability to efficiently manufacture composite laminates without the need for secondary processes like resin infusion or curing in an autoclave. However, currently there is no standard method for testing the bond strength of the steered in-situ consolidated composite tapes to the substrate. This study proposes a specially devised lap shear method to test the bond strength of a steered and in-situ consolidated tape. Sample preparation as well as testing procedure are described in detail and experimental results are presented. Samples for this study were manufactured using AFP process with Hot Gas Torch (HGT) as the heating system available at Concordia Center for Composites (CONCOM) and were tested using universal testing machine. To show the repeatability of the proposed lap shear test, a number of samples with different steering radii were tested and statistical data are presented.