leometwu的部落格

 http://www.bst-tsb.gc.ca/eng/rapports-reports/rail/2010/r10t0035/r10t0035.asp

 加拿大 交通安全部 事故鑑定報告

火車車禍 源自於輪軸疲勞斷裂, 下圖是火車車廂 推擠災情紀錄繪圖.

older fatigue fracture:舊疲勞裂面形成後因進廠, 車輛久置沒用而氧化.

Fresher fatigue fracture:較新(鮮)的疲勞裂面.中間白色帯區. 後來又出來服役, 疲勞裂面繼續擴大.

Overstress fracture:最後的過載驟裂區.

 摘譯:

• The characteristics observed in the primary and secondary zones indicate that they were produced by fatigue cracking. The appearance of the primary zone in contrast to the secondary zone suggests that the wheel set was dormant(久置沒用) for an extended period of time during which the axle primary fatigue crack became more oxidized. older fatigue fracture:舊裂面因車輛久置沒用而氧化. Fresher fatigue fracture:較新(鮮)的疲勞裂面. Overstress fracture:最後的過載驟裂區.
• 破裂起源點是一個軸外徑表面上,很久以前造成的的碰傷點-->引起應力集中.
• The fatigue crack originated from a single anomaly or impact mark on the axle surface that created a notch effect, acted as a stress raiser and initiated the crack. There were no other cracks observed elsewhere on the axle.
• The axle body and fracture surfaces were battered after the separation. Several heavily oxidized surface impact marks (dents)碰傷凹痕 were observed near the middle of the axle body that pre-dated the accident 車禍前就有的. One of these marks measured 0.08 inches deep and was located near the fatigue origin while a second mark measured 0.10 inches deep.