Fastener Failure Analysis: Two Interacting Failure Mechanisms

摘要

Today's case is somewhat unique in that it includes two distinct failure mechanisms. We will be examining failure of Shear Pins used in a mining operation that produces molybdenum and molybdenum products from mined ore. The Shear Pins were used in a roaster coupling assembly, but operated outside the oven and were typically not exposed to temperatures above 120°F. However, the coupling assembly was exposed to cyclic stresses and possibly low levels of sulfur dioxide liberated during the roasting process. The client requested that the primary purpose of the analysis was to examine the fractures and determine the failure mechanisms.