Mechanical properties of cross-ply and unidirectional 3D-printed continuous wire polymer composites

3D-printed continuous wire polymer composites (CWPCs) have been studied to increase the strength and stiffness of 3D-printed parts and to allow for in-part sensing for structural health monitoring. Most studies for CWPCs typically focus on unidirectional samples, where the wire reinforcement is parallel to the direction of loading. This study aims to characterize and compare unidirectional CWPC laminates in the longitudinal (UD-0°) and transverse (UD-90°) directions, and cross-ply CWPC laminates. A consolidation procedure previously developed was performed to reduce void content in the samples. Uniaxial tensile tests were performed on samples, while digital image correlation (DIC) was used for analysis of the strain fields on the surface of the samples during testing. Results showed that the tensile strength and elastic modulus of non-consolidated cross-ply samples were 36.60 MPa and 3.51 GPa, respectively. The consolidation procedure statistically improved the results for the UD-90° samples with a 20.0% and 15.0% higher tensile strength and elastic modulus, respectively. The experimental elastic modulus results were compared to classical laminate plate theory (CLPT) apparent laminate stiffness calculations to determine if the consolidation procedure increased the reliability of CLPT as a means to predict CWPC laminate behaviour.