Scientific Method Applied to Failure Analysis on Engineering Components

Abstract

Shank adapters or start bars are slim parts of hardened steel used in rock drilling hammers for the mining industry. This extreme type of work occasionally generates premature failures to the bar because of the heavy-duty working conditions.

In the present case, we will analyze the study of a bar, which has fractured suddenly and prematurely near the center of the piece. We are looking for an accurate method to detect the causes responsible for the problem applying the Scientific Method as a strategic tool to perform each of the steps in an orderly manner, without risking possible solutions prematurely or discarding hypotheses that seem unlikely at first sight.

It has been performed a detailed study including part design, material, and working conditions, considering all possible combinations of cause and effect that may influence the final result, and considering the same using a Pareto analysis.

Methodical

analysis is supported by actual experience through performance of mechanical tests, computer simulation of stress and fracture analysis through macroscopy and optical microscopy. From the results obtained, it was found that to suit the type of material used by the manufacturer, the adjustment of the variables in the heat treatment and certain geometric details in the construction of parts are essential to achieve the desired results, optimizing perforation work.