Mechanical behavior study of a lower limb prosthetic socket made of natural fiber reinforced composite
Trans-tibial sockets are commonly made of composites reinforced with expensive synthetic fibers. It would be very beneficial to replace conventional fibers by the natural ones produced locally using an abundant wild plant like Alfa (Stipa tenacissima) that is economically sustainable and environmentally friendly. Before use, sockets made of new material must be subjected to static and dynamic testing. Few studies so far have dealt with testing the mechanical behavior of sockets, especially cyclic testing. As there is no specific standard for mechanical socket testing, all works related to the mechanical experiments are based on the ISO 10328 standard. The objective of this preliminary experimental study is to investigate the feasibility of using Alfa fibers in trans-tibial sockets manufacturing and to determine their fatigue life. Both carbon fiber and Alfa fiber sockets were prepared and subjected to static and fatigue tests according to ISO 10328 standard.
The ultimate strength obtained during the static test on the carbon fiber socket and the Alfa fiber socket are respectively 3,400 N and 2,900 N. Fatigue testing on the Alfa fiber socket yielded a fatigue life of about 2,325,000 cycles.
Locally produced Alfa fibers, could be used as reinforcement of composite materials in orthopedic applications such as trans-tibial sockets. This could make prosthesis more affordable. Moreover, the results of this study could help to prepare a new specific standard for sockets tests, especially fatigue tests. Further mechanical tests and an economic viability study should be performed to ensure the feasibility of using Alfa fibers in sockets.