Some technological factors affecting the fatigue strength of FRP composites

. FRP composite materials possess the characteristics of high stiffness and high fatigue strength to weight ratioswhich are desirable for advanced aircraft components.The main objective of the present work is to study the STRACT flexural fatigue properties of aligned E-roving glass (ER1150 F-l83) reinforced polyester (OL 8520 A) composite rods.The rod specimens were made by modified pultrusion technique. The fiber distribution, fiber alignment andfractured surfacess of GFRP composite rods were examined byusing Scanning Electron Microscope.The effect of mean stress and vr on the behavior of S-Ndiagram of rod specimens has been investigated experimentally and compared with some published theoreticalmodels.The static flexure properties of this composites have been determined experimentally and compared with somepublished models at various fiber volume fraction (Vr). To analyze the static flexural test data, the static tension and compression tests were carried out on this compositerods at various vr.The three and two-parameter Weibull distribution functionhave been proposed to predict and analysis the staticmechanical properties of GFRP composite rods statistically.While the flexural fatigue life data of GFRP rods werepredicted and analyzed statistically using tow-parameterWeibull distribution function.The safe Qesign strength and fatigue life rods were estimated using time to first concept.data of GFRP failure (TTFF)