Abstract:
The primary objective of this research study is to design and manufacture a mechanical testing fixture for prosthetic external knee joint developed at School of Mechanical & Manufacturing Engineering, NUST. Aiming for the machine to be purely mechanical, cost efficient, sustainable yet simple in design and manufacturing; and also with an option for future modifications all the literature available about knee wear simulators, in vivo, in vitro testing was studied. On the basis of available literature, commercial machines and other available information regarding the design of knee wear simulators; three conceptual designs were developed modeled and analyzed. KAWAKITA Jiro method was used for needs assessments and design specifications development. Plough‟s method for decision matrix was used to pick the best suited conceptual design.
After the detail modeling, theoretical analysis of simple components and FEA analysis of complex components using ANSYS work bench were carried out. All the drawings and process plans were prepared keeping the DFM and DFA rules in consideration.
With the manufactured prototype any value of axial loading ranging from 10-1700N can be achieved with an error value which can further be reduced by decreasing the RPM of the crankshaft and reducing the friction between piston cylinder. Flexion angle can be varied manually. In future the model can further be modified by replacing the crank mechanisms with linear actuators using the same frame design.
