Flexural fatigue of marine laminates reinforced with woven roving of E‐glass and of Kevlar® 49 aramid

Abstract

A comparison of the flexural fatigue characteristics of E‐glass and Kevlar® 49 aramid in polyester and vinyl ester resin hand lay‐ups typical of boat hull laminates is presented. Data on unidirectional E‐glass and aramid composites from epoxy preimpregnated tapes are reported for comparison. The data indicate that while the initial flexural strength of E‐glass woven roving laminates is greater than that of aramid laminates, the runout stress of aramid laminates at 106 fatigue cycles is similar or superior to glass. S‐N curves for aramid laminates are flatter indicating better flexural fatigue resistance.

Effect of Moisture on Fatigue and Residual Strength Losses for Various Composites

“…The safety factors for pleasure craft may vary from 1.5 to 4.0 for the various subelements depending on ultimate and buckling strengths [2,3]. Greszczuk [4][5][6], Couch [7,8], Zweben [1], Fried [9], Macander [10], Hofer [11][12][13], and others [14,15] have all examined composites with regard to fatigue resistance of marine structural subelements. This cyclic stressing is coupled with exposure of the laminate to water.…”

“…They are subject to cyclic stresses throughout their service lives. Boats may be subject to as many as 10~-10~ cycles due to wave forces over the life of the vessel [1]. The wave forces produce flexural stresses in the hulls and the prediction of fatigue behavior of hulls from pure tension and compression fatigue data is difficult at best.…”

Modification of the dynamic damping behavior of epoxy/glass fiber composites via fiber coating with functional latices

“…The short beam bending test was carried out according to the European norm 01261005 (11,13,14). An Instron mechanical tester (model 8000) was used with hydraulic controls.…”