Design Failure Modes and Effects Analysis (DFMEA) of a Human Powered Recumbent Vehicle

Abstract

American Society of Mechanical Engineering (ASME) organizes International Human Powered Vehicle Challenge (HPVC) to provide a technical platform to budding technocrats to manifest the application of sound engineering design principles. This competition aims at "development of sustainable and practical transportation alternatives" [6]. In HPVC, students team up to engineer a highly efficient vehicle which can be utilized in our everyday use-from commuting to work, to carrying goods to market. A recumbent vehicle is a two/ three wheeler which places the rider in a laid-back reclining position. These vehicles are abundantly in use in West. They have wide applications-as means of transportation, recreation, exercise and as a freight vehicle. These vehicles are human powered and makes no use of fuel. Thus, they are eco-friendly in nature. In ASME HPVC, recumbents are designed and fabricated indigenously by the students. The recumbents in ASME HPVC are slightly modified to have fairings so as to have an increased speed for racing purpose. Given the non uniform roads that the vehicle will be subjected to especially in India, it is quite important to have a safe and strong design of the vehicle. Thus, the possible critical failure points and its mode of failure needs to be identified in the design stage itself and preventive measures be taken. An effective tool for making a failure analysis is DFMEA (Design Failure Modes and Effects Analysis) which is an augmentation of widely used Failure Modes and Effects Analysis (FMEA) technique. This analysis is done in the design stage. DFMEA has been used to predict and analyze various failure modes of a recumbent vehicle, its cause & effects and to outline preventive measures. Risk Priority Number (RPN) methodology is used to identify the critical parts which are more vulnerable to failure and needs extra attention.