Plain-woven GFRP Research Articles

Fatigue Damage Evaluation of Plain Woven GFRP under Tension/Torsion Biaxial Loading.

Material degradation and its mechanism in a plain woven GFRP under biaxial (combined tension-torsion) cyclic loading were studied. A plain woven glass fabric composite using polyester resin was selected for this study. Residual strength and stiffness reduction were observed to estimate the degree of fatigue damage. Based on the cumulative damage mechanics, a damage model to predict the stiffness reduction under biaxial cyclic loading was proposed. An attempt to predict biaxial fatigue life using the proposed model was also made, wherein the concept of the critical damage level was introduced. Experimental results confirmed that the model could predict both stiffness reduction and fatigue life reasonably.

極低温用高密度ＧＦＲＰにおけるガラス基材と機械的強度特性

Several kinds of mechanical strength of high density GFRP for cryogenic use are studied in order to check the combinations of glass fiber materials and matrix resins. Glass materials such as unidirectional woven cloth, plain woven cloth and roving cloth are selected from the view point of good mechanical characteristics. Resin content are established more less than value of 22 weight percent concerning low thermal contraction and GFRP are constituted in isotropy. It is found that the order of excellence in mechanical strength are unidirectional woven cloth GFRP, plain woven cloth GFRP and roving cloth GFRP at both room and cryogenic temperatures.The delamination strength of roving cloth GFRP is found to be extremely small.In order to decrease thermal contraction, the combinations of glass materials and fillers in GFRP are also studied. It is clear that the addition of fillers is effective in decrease the thermal contraction, but the addition of fillers make a deterioration of mechanical strength such as delamination strength, bending strength and tensile strength of GFRP.