MANUFACTURING AND NUMERICAL ANALYSIS OF ELBOW ORTHOSIS MADE OF POLYPROPYLENE – CARBON FIBER – POLYPROPYLENE

Abstract

In this work, elbow orthosis which represents one of the upper extremity orthosis is manufactured from two layers of polypropylene reinforced by a sheet of carbon fiber between them to construct a new composite material called "PCP" material. More flexibility is gained by minimization of the modulus of elasticity of polypropylene-carbon fiber- polypropylene to about 3.5 against old material. Average pressure is measured between the patient's arm and bicep part of elbow using a portable pressure device (has mat of sensors) which reach to about 217kPa. ANSYS PACKAGE version 11 is used for numerical analysis the bicep part of elbow by using the estimated internal pressure to investigate deformation and to determine the Von – Misses stress. The investigated numerical results showed that the new material maximizes the deformation to about 280% (still in elastic region) and make the design more safe by increasing the factor of safety more than 4 % against polypropylene material. Mechanical properties are measured also in present work by carrying out the tensile test for the two materials under study to conclude finally that, the sheet of carbon fiber which is added has increased the mechanical properties to about 8.25 % and 248 % for yield and ultimate stresses, respectively.