Investigation of Fracture Behavior for Natural Silk Fibers Used As Constitute In a Composite Fabric to Resist Hard Environmental Conditions
Natural fibers nowadays attract many applications in reinforcement polymer composites. Silk fiber as natural fiber is one of the excellent competitive for glass fiber, as it gained a relatively good specific mechanical and fracture properties. Therefore, silk natural fibers are used as clothing of the" Holy Kaaba” in Mecca. Millions of Muslims visit the Kaaba during the Hajj and Umrah seasons, which exposes their clothing to harsh conditions of tension, rupture, and sweat in the hands of visitors, in addition to other hard environmental conditions. Therefore, this work aims to investigate the resistance of such fabric cloth of natural silk using the center notch specimen test. This test is carried out on a dyed black woven of silk fiber on the fiber testing machine. The fracture surface energy in mode I loading is measured as 8.4 J/m2. This value is considered relatively high for natural fiber which can be increased with inserting other high stiffness fiber. The J-integral Finite element method is implemented to predict the mode I surface release energy using J-integral relation, the results is in good agreement with the experimental data.