Numerical and experimental evaluation of cryogenic tensile strength of woven fabric-reinforced glass/epoxy composites using open hole specimens

Abstract

A numerical and experimental evaluation of the tensile strength properties of woven glass fiber-reinforced polymer composite laminates at cryogenic temperatures was conducted by means of open hole specimens. Tensile tests were performed on specimens with a circular hole at room temperature, at 77 K, and at 4 K. The length of the hole edge damage zone corresponding to specimen failure was determined by microscopic examination of the fracture surfaces. A method based on finite element analysis was developed for estimating the cryogenic tensile strength of the unnotched woven laminates using the experimentally determined failure load and damage zone length. The results suggest that the tensile strength of woven composite laminates at cryogenic temperatures can be determined effectively by this approach.

Strength characterization of woven glass/epoxy composites under tensile fatigue loading at cryogenic temperatures using open hole specimens

“…A similar failure mechanism was observed in the open hole specimens of the woven GFRP laminates under tensile static loading. 16 In the specimens at 77 K and 4 K, an intense damage zone forms ahead of the hole. The dark area in the figure indicates the damage zone.…”

“…The P c values in the table are the average values of three data at each temperature. 16 The specimens were subjected to fatigue loading until failure. The cyclic frequency was 4 Hz for the room temperature tests.…”

“…in the absence of significant interlaminar delamination prior to failure. In this study, according to Shindo et al 16 and Watanabe et al, 17 we modeled the hole edge damage zone as a strip with length D in 2) and assumed that the normal stress in the loading direction (y-direction) yy is uniform within the damage zone ( yy ¼ 0 ). Note that the detailed process of damage initiation and growth was not modeled here.…”

“…Recently, our research group proposed the use of the open hole specimen for cryogenic strength property measurement in plain weave GFRP composite laminates, in order to avoid the cryogenic testing problems, such as the specimen slippage. 16 This method was also successful in determining the cryogenic tensile strength of five harness satin weave carbon fiber reinforced polymer (CFRP) laminates. 17 Since the open hole acts as sufficient stress riser to force the specimen failure from the hole, a similar approach may be suitable to prevent the specimen failure in the tab region during tensile fatigue loading and determine the fatigue strength properties of composites at cryogenic temperatures.…”

Comparative studies of experimental and numerical evaluation of tensile properties of Glass Fibre Reinforced Polyester (GFRP) matrix

“…They later compared the generated numerical result with the former, and observed that the two approaches were in good agreement with each other. Shindo et al [21] in their ingenuity introduced open-hole on composite laminate specimens to decide stress rising locus. They conducted tensile test and performed a microscopic examination on fractured surfaces of the failed specimens, which revealed that a high damage zone developed at the hole edge before further damage.…”