G. F. V. Voort.

ASM Handbook, Volume 11: Failure Analysis and Prevention; USA, 2002

Failures may be caused by any of the following factors or combinations of factors: Design shortcomings; Material imperfections due to faulty processing or fabrication; Overloading and other service abuses; Improper maintenance and repair; Environment-material interactions. Not all failures are catastrophic. Many failures involve a gradual degradation of properties or excessive deformation or wear until the component is no longer functional long before its design life is reached. Failures due to wear or general corrosive attack usually are not spectacular failures but account for tremendous material losses and downtime every year. Of course, early failures of the spectacular catastrophic order capture the most attention - and rightly so. Nevertheless, all failures deserve the attention of the investigator, because they reduce production efficiency, waste critical materials, and increase costs. In some instances, they cause considerable damage or personal injury. Finally, failures can result in costly litigations.

C. R. Manning and T. C. Wenzel.

ASM Handbook, Volume 11: Failure Analysis and Prevention; USA, 2002

Failure analysis is generally defined as the investigation and analysis of parts or structures that have failed or appeared to have failed to perform their intended duty. The purpose is to determine how and why a part or structure has failed. In contrast, the focus of accident reconstruction is to determine how and why an accident occurred. Clearly, there is a certain degree of commonality between the terms, because most, if not all, failures can be categorized as accidents. However, not all accidents can be categorized as failures, because many accidents occur due to human error. There may be no actual physical failure of a part and/or device, although parts may 'fail' because of the accident itself. This article provides a brief review of some general concepts on the use of modeling. A model is a physical, mathematical, or logical representation of a physical system or process. The use of modeling can be a very powerful tool for information pertaining to the reconstruction of an accident. Whether the modeling consists of simple mathematical modeling of a physical system or more complex computer modeling of a system or part, the modeling technique may directly or indirectly give insight to the cause of an accident.