Experimental Study of Flexural Strength of Laminate Composite Material

Abstract

The effect of fiber volume fraction on the flexural properties of the laminated composite test specimens constructed of two layers, one of them reinforced with glass fiber and the other layer reinforced with Kevlar fiber has been investigated experimentally. The results illustrate that tension stress decreases with the increase in fiber volume fraction of glass fiber of the lower layer while it increases with the increase of Kevlar volume fraction of the upper layer. As for compression stress, it increases with the increase in volume fraction of glass fiber of the lower layer while it decreases with the increase of volume fraction of Kevlar fiber of the upper layer. The results also show the maximum value of tension stress (= 25.3 MPa.) at V f of Glass fiber (= 15 %) and V f of Kevlar fiber (= 60 %), while the maximum value of compression stress (= -17.1 MPa.) at V f of Glass fiber (= 60 %) and V f of Kevlar fiber (= 15 %). ‫ﺼﻔﺎﺌﺤﻴﺔ‬ ‫ﻤﺭﻜﺒﺔ‬ ‫ﻟﻤﺎﺩﺓ‬ ‫ﺍﻷﻨﺤﻨﺎﺀ‬ ‫ﻻﺠﻬﺎﺩﺍﺕ‬ ‫ﺍﻟﻌﻤﻠﻴﺔ‬ ‫ﺍﻟﺩﺭﺍﺴﺔ‬ ‫ﺍﻟﺨﻼﺼﺔ‬ ‫ﻋﻤﻠﻴﺎ‬ ‫ﺍﻟﺒﺤﺙ‬ ‫ﺃﺠﺭﻱ‬ " ‫ﻟﻌﻴﻨﺎﺕ‬ ‫ﺍﻷﻨﺤﻨﺎﺀ‬ ‫ﺨﻭﺍﺹ‬ ‫ﻋﻠﻰ‬ ‫ﻟﻸﻟﻴﺎﻑ‬ ‫ﺍﻟﺤﺠﻤﻲ‬ ‫ﺍﻟﻜﺴﺭ‬ ‫ﺘﺄﺜﻴﺭ‬ ‫ﻟﺩﺭﺍﺴﺔ‬ ‫ﺍﺤﺩ‬ ،‫ﻁﺒﻘﺘﻴﻥ‬ ‫ﻤﻥ‬ ‫ﻤﻌﻤﻭﻟﺔ‬ ‫ﺼﻔﺎﺌﺤﻴﺔ‬ ‫ﻤﺎﺩﺓ‬ ‫ﻓﺤﺹ‬ ‫ﻫﺎﺘﻴﻥ‬ ‫ﻯ‬ ‫ﺍ‬ ‫ﻭﺍﻟﻁﺒﻘﺔ‬ ‫ﺍﻟﺯﺠﺎﺝ‬ ‫ﺒﺄﺍﻟﻴﺎﻑ‬ ‫ﻤﻘﻭﺍﺓ‬ ‫ﻟﻁﺒﻘﺘﻴﻥ‬ ‫ﺍﻟﻜﻔﻠﺭ‬ ‫ﺍﻟﻴﺎﻑ‬ ‫ﻤﻥ‬ ‫ﻤﻘﻭﺍﺓ‬ ‫ﺍﻻﺨﺭﻯ‬ . ‫ﺒﻴﻨﺕ‬ ‫ﻟﻠﻁﺒﻘـﺔ‬ ‫ﺍﻟﺯﺠـﺎﺝ‬ ‫ﻷﻟﻴﺎﻑ‬ ‫ﺍﻟﺤﺠﻤﻲ‬ ‫ﺍﻟﻜﺴﺭ‬ ‫ﺯﻴﺎﺩﺓ‬ ‫ﻤﻊ‬ ‫ﻴﻘل‬ ‫ﺍﻟﺸﺩ‬ ‫ﺃﺠﻬﺎﺩ‬ ‫ﺒﺎﻥ‬ ‫ﺍﻟﻨﺘﺎﺌﺞ‬ ‫ﻟﻠﻁﺒﻘ‬ ‫ﺍﻟﻜﻔﻠﺭ‬ ‫ﻷﻟﻴﺎﻑ‬ ‫ﺍﻟﺤﺠﻤﻲ‬ ‫ﺍﻟﻜﺴﺭ‬ ‫ﺯﻴﺎﺩﺓ‬ ‫ﻤﻊ‬ ‫ﻴﺯﺩﺍﺩ‬ ‫ﺒﻴﻨﻤﺎ‬ ،‫ﺍﻟﺴﻔﻠﻰ‬ ‫ﺔ‬ ‫ﺍﻟﻌﻠﻴﺎ‬ . ‫ﺍﻟﻀـﻐﻁ‬ ‫ﺍﺠﻬﺎﺩ‬ ‫ﻭﺃﻥ‬ ‫ﺍﻟﺤﺠ‬ ‫ﺍﻟﻜﺴﺭ‬ ‫ﺯﻴﺎﺩﺓ‬ ‫ﻤﻊ‬ ‫ﻴﺯﺩﺍﺩ‬ ‫ﺍﻟﺤﺠﻤﻲ‬ ‫ﺍﻟﻜﺴﺭ‬ ‫ﺯﻴﺎﺩﺓ‬ ‫ﻤﻊ‬ ‫ﻴﻘل‬ ‫ﺒﻴﻨﻤﺎ‬ ‫ﺍﻟﺴﻔﻠﻰ‬ ‫ﻟﻠﻁﺒﻘﺔ‬ ‫ﺍﻟﺯﺠﺎﺝ‬ ‫ﻷﻟﻴﺎﻑ‬ ‫ﻤﻲ‬ ‫ﺍﻟﻌﻠﻴﺎ‬ ‫ﻟﻠﻁﺒﻘﺔ‬ ‫ﺍﻟﻜﻔﻠﺭ‬ ‫ﻷﻟﻴﺎﻑ‬ . ‫ﻜﻤﺎ‬ ‫ﺍﻟﺸﺩ‬ ‫ﻷﺠﻬﺎﺩ‬ ‫ﻗﻴﻤﺔ‬ ‫ﺃﻋﻠﻰ‬ ‫ﺒﺎﻥ‬ ‫ﺍﻟﻨﺘﺎﺌﺞ‬ ‫ﺒﻴﻨﺕ‬ (= 25.3 MPa.) ‫ﻋﻨـﺩ‬ V f ‫ﻷﻟﻴـﺎﻑ‬ ‫ﺍﻟﺯﺠﺎﺝ‬ (=15 %) ‫ﻭ‬ V f ‫ﺍﻟﻜﻔﻠﺭ‬ ‫ﻷﻟﻴﺎﻑ‬ (= 60 %) ‫ﺍﻟﻀﻐﻁ‬ ‫ﻷﺠﻬﺎﺩ‬ ‫ﻗﻴﻤﺔ‬ ‫ﺃﻋﻠﻰ‬ ‫ﺒﻴﻨﻤﺎ‬ ، (= -17.1 MPa.) ‫ﻋﻨﺩ‬ V f ‫ﺍﻟﺯﺠﺎﺝ‬ ‫ﻷﻟﻴﺎﻑ‬ (=60 %) ‫ﻭ‬ V f ‫ﺍﻟﻜﻔﻠﺭ‬ ‫ﻷﻟﻴﺎﻑ‬ (= 15 %) . Notation: b Thickness (m). E 1 Modulus of elasticity parallel to the fiber direction (N/m