Comparative Analysis of Textile Characteristics and Mechanical Properties of E‐Glass Woven Fabrics in Epoxy Composites Under Cryogenic Conditions

ABSTRACT The design and optimization of composite materials for applications that need ultra‐low temperatures and extreme thermal cycling is crucial, particularly in liquid gas storage tanks. Among the materials utilized in cryogenic applications, E‐glass fiber reinforced epoxy composites have gained significant interest. Despite substantial progress in studying glass fiber reinforced epoxy composites under cryo‐conditioning, there is a need for further research into the investigation of textile characteristics and how these factors mitigate or exacerbate failure mechanisms in epoxy composites. Therefore, the main objective of this research is to explore the textile characteristics and mechanical performance of epoxy composites reinforced with woven E‐glass fabrics under cryogenic conditions. Three commercially available fabrics weighing 200, 400, and 600 g.m −2 were analyzed. Focusing on the textile characteristics (areal density of fabric, fiber diameter, linear density of tow, warp/weft density, number of monofilaments, and tensile behavior of monofilaments), the tensile strength, maximum strain, and toughness of the composite samples in 0° of loading direction were investigated before and after being subjected to cryo‐conditions (5 h in liquid nitrogen). After identifying the best‐performing fabric as the optimal choice, further investigations were conducted by preparing the composite samples with a 45° rotation of the fabric layers with respect to the loading direction of 0°. Different configurations (4‐layers vs. 8‐layers of fabric) were adopted as the reinforcements for the composite structures, and the samples were subjected to various cryogenic conditions, i.e., (1) fully dipped into cryo‐reservoir for 5 h, (2) twice fully dipped into cryo‐reservoir for 5 h, or (3) localized cryo‐conditioned for 5 h (one face in direct contact with cryo‐liquid). Results indicate significant variations in performance based on fabric type, with high strength monofilaments demonstrating superior strength and maximum strain to other alternatives. Furthermore, the thermal shocks experienced by the composites during cryogenic exposure led to observable losses in tensile properties, particularly under repeated cryogenic shocks. The study reveals that the thermal exchange within thicker samples, such as the 8‐layer configurations, led to an imbalance in thermal stress distribution, resulting in unexpected mechanical failures. The 8‐layered sample which had only one face in direct contact with the cryogenic liquid showed more significant strength reduction compared to the sample fully immersed in liquid nitrogen.