Failure Analysis of a Bucket Elevator Shaft
| Autor: | B. Gurudath, Pavankumar R. Sondar, Subray R. Hegde, J. K. Rakshan Kumar, Kamal Kishore Kumawat, Vijinigiri Tejaswi |
|---|---|
| Rok vydání: | 2021 |
| Předmět: |
Heat-affected zone
business.product_category Elevator business.industry 020209 energy Mechanical Engineering Fractography 02 engineering and technology Welding Structural engineering Bucket elevator law.invention Counterweight 020303 mechanical engineering & transports 0203 mechanical engineering Mechanics of Materials law 0202 electrical engineering electronic engineering information engineering General Materials Science Safety Risk Reliability and Quality business Sprocket Geology Brittle fracture |
| Zdroj: | Journal of Failure Analysis and Prevention. 21:563-569 |
| ISSN: | 1864-1245 1547-7029 |
| DOI: | 10.1007/s11668-020-01101-7 |
| Popis: | Present work investigates the in-service break down of a bucket elevator in a chemical processing plant. The elevator was used for lifting bulk Di-Ammonium Phosphate and broke down due to premature failure of a shaft made of EN19 steel. The investigation comprises a detailed metallurgical failure analysis involving site visit, visual inspection, fractography, and metallography. The investigation reveals that, about 2 years prior to the failure, the shaft was tack-welded to the sprocket hub and a gib-head key near the keyway to avoid the frequent loosening of the key. The inspection during the site visit confirms that the shaft-sprocket assembly was subjected to in-service jerky loading condition along with uneven stress distribution due to misaligned counterweight. The investigation concludes that a crack was initiated in the shaft at the heat affected zone of the tack-welded spot, propagated transversely by fatigue due to in-service cyclic loading, and terminated catastrophically by a brittle fracture during the service. Tack welding, coupled with uneven stress distribution in the shaft due to misaligned counterweight system, is adjudged the root cause of this failure. Suitable remedial measures are suggested to avoid such a failure in the future. |
| Databáze: | OpenAIRE |
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