Material Characterization and Fatigue Analysis of Lower Limb Prosthesis Materials

Abstract

Fiber reinforced plastics (FRP) have been widely used as one of the most interesting materials for structural engineering applications due to their excellent mechanical and physical characteristics for example, high specific strength and high specific stiffness. One of the most successful applications of FRP is the fabrication of prosthetic socket because of its lightweight and high strength to weight ratio. In this work, the influence of volume fraction and lay-up of layers on the fatigue and mechanical properties (Tensile and flexural test) were investigated for composite materials. Woven carbon fibers, knitting perlon stockinet as reinforcement layers and acrylic resin as a matrix used in this investigation with different volume fractions. Two proposed composite materials were manufactured by vacuum molding techniques and matrix material fabricated by pouring mixture of resin with 2% of hardener into a shallow flat container and compared effect of fiber volume fraction on tensile mechanical properties of matrix resin where the first proposed laminate have eight layers with lay-up (3-perlon + 2-carbon fiber + 3-perlon) and the other have ten layers with different lay-up (2-perlon + 1-carbon fibers + 1-perlon + 2-carbon fiber + 1-perlon + 1-carbon fibers + 2-perlon). The second proposed composite material gave an excellent results in tensile, flexural and fatigue tests. The ultimate tensile strength and Young's modulus increased by approximately factors 3.77 and 2.61 respectively with increasing fiber volume fraction into 40.63% and by approximately factor 1.96 and 1.36 respectively for 26.2% fiber volume fraction of first proposed composite if they compared with matrix material and the endurance limit of the second composite material was about twice the endurance limit for the first where it was a positive indication.