| Summary: | 碩士 === 國立成功大學 === 機械工程學系碩博士班 === 98 === This research aimed to use rapid prototyping (RP) technology to manufacture prosthetic socket, which is then reinforced by coating unsaturated polyester resin (UPR) layers to prevent breakage at the proximal brim of a socket while wearing the prosthesis. To simulate the use of transtibial socket, a type of specimen to determine the flexural strength is designated based on ASTM D790 standard. Similar to resin-reinforced RP socket, the specimens for three-point bending test are composed of an RP layer and a UPR layer. Since there are several parameters that affect the strength of test specimens, Taguchi experimental method was employed to reduce test runs by choosing L18 orthogonal array. To implement the three-point bending test according to ASTM D790 standard, an MTS universal testing machine was used in this study.
The factors that affect the flexural strength include RP material, thickness of the RP layer and thickness of UPR layer coating, which are then combined with appropriate levels to form L18 orthogonal array. In the result of analysis of variance (ANOVA) based on the experimental data, the factors of UPR layers and RP materials affect the flexural strength more than RP thickness. Although the maximum flexural strength of the experiments is the main objective, the maximum flexural force will be more practical data to meet the actual force applied condition on a transtibial socket. The analysis result also showed that UPR layers is the most influenced factor on the maximum flexural force. In other words, the thicker the UPR layers of a socket, the more difficultly broken the prosthetic socket. And, the RP material and its thickness do not significantly affected flexural force.
The study concluded that the parameters of vertical RP forming direction, thin ABS M30 RP material and seven-sock-layer UPR were chosen as the flexural strength and flexural force of test specimen based on that combined factors is larger than that of traditional UPR socket. Using the chosen parameters, a resin-reinforced transtibial socket was fabricated for a volunteer amputee. The motion analysis and trial use of the prosthetic socket verified the applicability of resin-reinforced socket. Long-term trial use and durability test are underway.
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