Risk Assessment of Ferris wheel Trusses Based on FMECA-Fuzzy Evaluation Method

The truss is a key part of a Ferris wheel system and affects the safety of the entire Ferris wheel system directly. This paper proposes an analytical method based on failure modes, effects, and criticality analysis (FMECA) and a fuzzy evaluation method for evaluating the risk level of the trusses of the Ferris wheel system; the analytical method includes qualitatively analyzing the operation, failure modes, failure cause, failure rate, and severity through FMECA and quantitatively assessing the safety by using the fuzzy evaluation method. A case study is presented to demonstrate the effectiveness, reliability, and practicability of the analytical method in assessing the risk level of the Ferris wheel trusses. The results show that the highest risk of the failure mode is truss fracture and that the truss itself has a lower level of risk. The results coincided with the real test. Introduction Ferris wheel is one of the most important amusement equipments in the playground and it represents the size and sophistication of a play ground. Visitors ride the Ferris wheel to see the scenery with the wheel rotates slowly and continuously. A Ferris wheel always consists of a wheel, driving devices, columns, and a control room. The trusses are the most popular form of the wheel. They extend from the main shaft and then the outer trusses forming the large wheel; thus, the trusses require strict quality control and assurance. The traditional FMECA evaluation results were expressed qualitatively and have thus used for presenting abstract descriptions. Furthermore, the safety of Ferris wheel trusses has not been evaluated. In the present study, the FMECA and the fuzzy evaluation method were combined to assess the risk level of Ferris wheel trusses. The proposed method may provide a reference for future research on the safety of large recreational facilities. FMECA FMECA consists of two parts: Failure modes and effects analysis (FMEA) and criticality analysis (CA)[1]. FMEA. Essentially, FMEA is a qualitative analysis method that involves a hardware method, function method, and mixed method. The hardware method is a bottom-up failure analysis method that can be used to analyze failure modes, failure causes, and effects of each component on the basis of design drawings[2]. The function method is also an up-bottom failure analysis method for analyzing each function of products without the use of design drawings. The mixed method is a combination of the hardware and function method and is used to assess function failure and component failure in complex systems. CA. The CA method involves a criticality matrix and risk priority number (RPN). The RPN is a qualitative analysis method in which the failure probability and severity of equipment failures are International Conference on Manufacturing Engineering and Intelligent Materials (ICMEIM 2017) Copyright © 2017, the Authors. Published by Atlantis Press. This is an open access article under the CC BY-NC license (http://creativecommons.org/licenses/by-nc/4.0/). Advances in Engineering, volume 100