Experimental and numerical analysis of the effect of temperature on the mode I and mode II delamination of glass fiber woven composites
Marcio Moreira Arouche, Marko Pavlović
Abstract
This work focuses on investigating the effect of short-term changes of temperate on the mode I and mode II glass fibers woven composite interleaved with layers of chopped strand mat (CSM). Existing experimental and numerical methods are critically applied to characterize and model the delamination of the woven-CSM composite laminate. Double cantilever beam (DCB) and end notched flexure (ENF) tests are performed in non-post cured and post cured specimens at room temperature (21 °C), and the operational conditions are investigated post cured specimens are tested in low (-10 °C) and high (70 °C) temperatures. The fracture behavior is characterized using the compliance-based beam method (CBBM) while crack length estimations based on the specimen compliance are compared to direct measurements from DIC. Then, failure analysis was performed using an optical profilometer and scanning electron microscopy (SEM). Temperature changes affected the preferential crack path for the woven composite delamination in mode I loading conditions. However, the crack path in mode II fracture tests remained independent of the testing temperature. Fractography results revealed temperature-dependent failure mechanisms, with a transition to more fiber/matrix interface debonding and matrix deformation in higher temperatures. The increase of matrix ductility translated into an improvement of the delamination fracture toughness in both mode I and mode II loading conditions. Finally, non-linear cohesive zone models (CZMs) directly derived from experimental results were capable of accurately reproduce the mode I and mode II delamination fracture behavior of the woven-CSM composite in different temperatures.