Effects of Ultraviolet Radiation with and Without Heat on the Fatigue Behavior of Below-Knee Prosthetic Sockets

This work focused on below-knee (BK) prosthetic socket s, which have gained wide application due to the increasing number of patients with BK amputation as a result of terrorist attacks and life-threatening si tuations in warstricken areas, such as Iraq. Given the hot weather in Iraq, a number of studies have explored the effe cts of temperature on specific socket materials. The current study attemp ts to explain the effects of ultraviolet (UV) radiat on, in combination with temperature, on the properties of socket materials. In the experimental work, two sets of specimens, na mely, Material A (acrylic resin and hardener reinforced with 10 layer s of perlon, and Material B (acrylic resin and harde n r reinforced with 8perlon layers and2carbon fibers), were manufactured using a vacuum technique. The socket materials were subjected to tensile testing to obtain their mechanical properti es. The failure characteristics of sockets were det ermined by fatigue testing using a machine (alternating bending fatigu e) manufactured specially for this purpose. Fatigue t sting was carried out in four different exposure environments (at roo m temperature with and without UV radiation and at 50 °C with and without UV radiation). Interface pressure between the stump and the socket was measured using an F-socket device. In the numerical study, a prosthetic socket was drawn by usi ng AUTOCAD software. Finite element technique (ANSYSWorkbench 15) was used to analyze and evaluate the f atigue characteristics by observing the maximum str e s, total deformation, and safety factor. Results show that the modulus of elasticity (19.7), ultimate tensile str ength, and yield stress of socket material sunder group B were superior to th ose of group A. The material with carbon fiber reinfo rcement showed the highest fatigue limit and safety factor values (5.0638, 4.6565, 5.0424, and 4.4613). However, the c ombined effect of temperature and UV radiation decreased the safety fa ctors and rendered the materials of group A as unsa fe. The equivalent von Mises stress reached a maximum of16.9MPaand was centered at the anterior side of the tibia bone.