116 スマートワッシャによる緩み検知に対するスーパーバイザ手法の適用(セッション4 評価・診断IV)

抄録

The objective of this study is the loosening detection of bolted joints without human involvement by applying the concept of structural health monitoring. The smart washer consists of the cantilever available to detect bolt loosening by using flexibility of cantilever and self-sensing/actuation function. The principle of how to detect the loosening of a bolt is the basis that the natural frequency of a smart washer system vary depending on a bolt tightening axial tension. The natural frequency of the smart washer was identified by using 4SID in previous papers. The natural frequency of the smart washer was identified by using the sub-space state space identification method in previous papers. However, 4SID was confirmed unsuitable for the periodic maintenance. This paper is proposed that the smart washer is detected bolt loosening by the supervisory method by using multiple observer. Numerical simulation results for several bolt loosening state for the bolted joint indicate the effectiveness of the proposed loosening detection method.