3111 金属の振動疲労における非線形変形に伴う高調波の発生(OS.10 故障診断・予知・メンテナンス・安全性)

概要

論文の詳細を見る
The resonant vibration tests were carried out on type 304 stainless steel to develop the non-destructive method for evaluating fatigue damage. The authors have studied the critical strain amplitude of fatigue above which dislocation multiplication begins to occur. The critical strain amplitude was determined from the stain amplitude dependence of internal friction which is due to dislocation motion of breakaway from pinning points and multiplication. Such dislocation motion gives the nonlinear stress-strain relationship of resonant vibration. The non-linear stress-strain relationship yields higher harmonics on vibration. In this study, the dynamic displacement of resonant vibration was measured using a non-contact laser displacement meter. The 3rd harmonics was strongly dependent on the strain amplitude over the region above the critical strain amplitude, though hardly be identified below that strain. As a consequence, detecting higher harmonics could be used to determining the critical amplitude of vibrating structures such as small bore piping systems with branch joints.
社団法人日本機械学会の論文
2000-12-12