Diagnosis of Engineering Failures

Abstract

This paper is divided into three parts. The first deals with the general aspects of failure investigations discussing the kind of staff and facilities required and emphasising the need for speedy, accurate reporting: The second part is concerned with the nature of engineering failures and analyses the results of almost 1000 investigations with regard to failure modes, field of application and components that fail. The third and major part describes a variety of typical failure investigations that illustrate the concepts outlined in Part 1. These mclude problems of bad fitting, corrosion and abrasive wear on plain bearings; the corrosion of exhaust valves and spark plug electrodes by deposited lead compounds and methods for measuring operating temperatures on inaccessible components; exhaust valve sinkage (valve seat recession) on engines running on ash-free fuels such as naturalgas and unleaded gasoline; the size factor in mechanical testing with special reference to anchors; fretting fatigue; cavitation damage in fuel injection systems and diesel engine cylinder liners, and stress corrosion cracking of Admiralty brass condenser tubes cooled by Thames river water.