A derailment investigation of a large capacity overhead bridge crane was conducted based upon the only accessible and remaining physical evidence, a separated wheel flange. A metallurgical evaluation limited to visual examination and optical microscopy of the separated wheel flange in conjunction with 3D modeling based upon nominal track and wheel dimensions confirmed that the root cause of the crane derailment was the result of aggressive operation. The wheel fracture contained fracture morphology, indicating that a crack initiated at the interface between the wheel tread and the flange as a result of impact loading with the side of the rail head. After initiation, the crack at the base of the flange propagated as a result of repeated loading events. Having progressed to a critical crack length, the compromised wheel flange was driven into the rail, bending the flange outward resulting in the observed wear groove that matched the gauge corner of the crane rail. The flange eventually separated from the wheel resulting in a derailment. Utilizing scene documentation and information provided by both the crane operator and crane manufacturer, it was possible to determine that operation of the crane resulted in heavy loading events necessary to initiate cracking at the base of the wheel flange.

A mechanical and metallurgical analysis was performed on a 10-inch circular saw blade involved in a table saw incident in which a fragment of a carbide tip from the saw blade struck an individual in the eye. This individual claimed the saw blade had never previously been used. Examination of the carbide tip fragment revealed yellow paint on the fracture surface indicating a preexisting crack was present during the saw blade assembly process. Chemical analyses indicated that the residue found on the saw blade was consistent with chipboard (OSB). Exemplar testing found similar wear patterns between the subject saw blade and an exemplar used to cut chipboard. Stress analysis of a saw blade tip indicated the stresses generated due to blade rotation alone would not be sufficient to cause fracture or separation of a carbide tip even if the carbide tip contained a preexisting crack. It was concluded that the carbide tip likely fractured and separated from the saw blade due to a preexisting crack in the carbide tip which grew from impact with a hard object during cutting operation.

In their paper the modeling of communication between hardware and software modules at different abstraction levels for different design tools is addressed. This is achieved by using a multi-view library concept in order to hide specific hardware/software implementation details and communication schemes. The same C and VHDL descriptions can be used for both co-simulation and hardware-software co-synthesis.

A forensic investigation was performed on an ATV that was involved in an accident in which the vehicle struck a tree. Postaccident, the front knuckle/tie rod end connection was found to be loose. The prevailing torque nut was found positioned at the end of the tie rod end bolt such that there was a gap between the face of the nut and the knuckle. The subject nut exhibits machining asperities that resulted from close contact with the knuckle face. EDS analysis of the corrosion product ring on the knuckle face revealed the corrosion product was zinc oxide, which had formed due to galvanic corrosion between the galvanized nut and the carbon steel knuckle. Scuffing patterns on the nut, wear patterns on the bolt, and lack of damage to the knuckle corrosion ring confirmed that the nut could not have loosened from the as-manufactured position to the postaccident position. No viable nut loosening mechanism was identified other than deliberate, manual manipulation.

During maintenance, a post-World War II military training airplane experienced a ground fire that resulted in damage to the lower fuselage forward of the wing spar carry-through structure. Although the fire was contained approximately 18 in. forward of the carry-through structure, existing airworthiness concerns and the critical nature of this area resulted in the need to evaluate the possibility of damage resulting from the fire. A correlation between the electrical conductivity and mechanical properties of the aluminum structure was established from components that were fire damaged and, consequently, removed during repair of the aircraft. This correlation was then used to non-destructively evaluate the integrity of the material in the carry-through structure and, ultimately, confirmed that the carry-through structure did not have to be replaced.

Plastics EngineeringVolume 71, Issue 8 p. 32-37 Consultant's Corner Failure Analysis of a Glass-Filled Phenolic Resin Power-Steering Pump Pulley Michael D. Hayes, Michael D. Hayes Engineering Systems Inc., Atlanta, Georgia, USASearch for more papers by this authorMichael E. Stevenson, Michael E. Stevenson Engineering Systems Inc., Atlanta, Georgia, USASearch for more papers by this authorDustin A. Turnquist, Dustin A. Turnquist Engineering Systems Inc., Atlanta, Georgia, USASearch for more papers by this author Michael D. Hayes, Michael D. Hayes Engineering Systems Inc., Atlanta, Georgia, USASearch for more papers by this authorMichael E. Stevenson, Michael E. Stevenson Engineering Systems Inc., Atlanta, Georgia, USASearch for more papers by this authorDustin A. Turnquist, Dustin A. Turnquist Engineering Systems Inc., Atlanta, Georgia, USASearch for more papers by this author First published: 01 September 2015 https://doi.org/10.1002/j.1941-9635.2015.tb01395.xAboutPDF ToolsExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinkedInRedditWechat Volume71, Issue8September 2015Pages 32-37 RelatedInformation

This is an ASM International sponsored journal. The Journal is also closely linked with the ASM Failure Analysis committee, which manages technical content and programming for the society. By virtue of ASM’s role as the materials information society, our readership and author base is strongly associated with materials professionals. That said, in the more than 10 years of the Journal’s existence, we have published papers that encompass every major engineering discipline and many scientific disciplines as well. While many of our articles would still be best characterized as metallurgical failure analyses, I submit that purely metallurgical failure analysis is a narrowing discipline of significance. I certainly feel that altogether failure analysis is a growing discipline, and definitely some investigations are, by their very nature, only metallurgical. That is, in my opinion, becoming the exception rather than the rule. Several years ago, as associate editor, I wrote an editorial centering on this topic. My thesis then was that the metallurgical failure analyst, often put in the central position of an investigation, needed to think beyond the boundaries of the metallurgical lab. Underlying that commentary was the notion that the materials investigator often had the best perspective to critically interpret the available physical evidence in a given investigation. These interpretations, however, can be misguided if not armed with the situation-specific knowledge of the component, system or discipline of interest. That commentary is increasingly true today, as more complex, interconnected and sophisticated engineering systems and designs are utilized. The multidisciplinary and interdisciplinary nature of failure analysis is often written about in our community. Increasingly, even simple investigations are relying upon the expert analysis of multiple investigators in multiple disciplines in order to thoroughly understand an event or its cause(s). The complex interactions of different technical disciplines are now been focused together in an investigative role the way they were once only integrated in complicated design engineering contexts. This is good, necessary and in fact, the expected evolution for our field. All of this brings us back to the question ‘‘What discipline?’’ What discipline is the right one for failure investigation? I, personally, am partial to metallurgical engineering and applied mechanics, those being my home disciplines. I also recall my graduate advisor, a metallurgist, noting to me in a moment of apparent candor that ‘‘the mechanical engineers have it right, they just don’t know why. We (metallurgists) suffer from having it in focus in the microscope but blurry in the real world.’’ M. E. Stevenson (&) Engineering Systems Inc., 6190 Regency Parkway, Suite 316, Norcross, GA 30071, USA e-mail: mestevenson@esi-atl.com