Paper Title:
Failure Analysis of a Hammer Drill Shaft under Complex Loading Paths and Severe Environmental Conditions
  Abstract

This paper describes the failure investigation of a tubular shaft that is part of a hammer drill assembly. The failure investigation was particularly challenging as the fracture surfaces were completely damaged during and subsequent to the failure process. However, careful examination of the component and its assembly revealed many clues that pointed to the root causes of failure. It was determined that the shaft was subjected to impact, fatigue, bending and torsional loads simultaneously at elevated temperatures. The basic failure mode was identified as a combination of torsional fatigue and rotating bending fatigue failure that originated on the inside diameter of the shaft. The root causes were determined to be operational overload in combination with rough machining marks on the bore surface and higher than necessary operating torque required to overcome the dry adhesive friction in the system. The preventative measures recommended were many-fold including improving surface finish on the bore diameter, reducing dry sliding friction, decreasing the overall level of dynamic loads by appropriate design changes and adding a surface strengthening heat treatment

  Info
Periodical
Materials Science Forum (Volumes 638-642)
Main Theme
Edited by
T. Chandra, N. Wanderka, W. Reimers , M. Ionescu
Pages
3889-3894
DOI
10.4028/www.scientific.net/MSF.638-642.3889
Citation
P. A. Manohar, "Failure Analysis of a Hammer Drill Shaft under Complex Loading Paths and Severe Environmental Conditions", Materials Science Forum, Vols. 638-642, pp. 3889-3894, 2010
Online since
January 2010
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Price
$32.00
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