Showing papers in "Engineering Failure Analysis in 1996"

TL;DR: Tooth bending fatigue is one of the most common modes of fatigue failure in gears and it results in progressive damage to gear teeth and ultimately leads to complete failure of the gear as mentioned in this paper. But it is difficult to diagnose and it may not always be the case.

TL;DR: In this article, the efficiency of several fatigue crack retarding methods were examined, including repair welding, welded metal reinforcements, adhesively bonded CFRP patches, single peak tensile overloads and fatigue crack arrest holes.

TL;DR: In this paper, the analysis of a fatigue failure of a connecting rod in a medium-speed diesel engine is described. But the difficulties in making a sufficiently good FE model with exact geometry of fine details and with all important nonlinearities are explained.

TL;DR: In this paper, a new method of fatigue analysis for components is outlined; the novelty of the method is that it uses fracture mechanics concepts without introducing a crack into the component, and stress concentrations are analysed by examining their stress fields and comparing these with the stress fields of cracks of standard geometry.

TL;DR: In this article, the pitting resistance equivalent (PRE) was used as a fine-tuning aid in materials selection and the limits of the PRE as a tool for estimating the critical pitting temperature have been demonstrated using published data.

TL;DR: In this article, the authors described the analysis of the failure of a steel truss motorway bridge caused by insufficient weld penetration, and the cause of failure was fatigue crack initiation and propagation in a welded vertical member.

TL;DR: In this paper, failure analysis and life prediction of a large fin plate heat exchanger required metallurgical analysis, the development of a model for thermal and stress analysis, and a fatigue model.

TL;DR: Early failures occurred with two sizes of wheel bolts used for attaching front wheels and dual rear wheels to heavy truck hubs as mentioned in this paper, and resulted in fracture of the bolts, and was a response to the material and process specification which produced a steel microstructure highly susceptible to hydrogen-assisted stress cracking.

TL;DR: In this article, an eight-stage feed pump in a urea-manufacturing plant started showing a high overall vibration level 3 years after commissioning, and the level continued to remain high for about 2 years.

TL;DR: In this article, a structural analysis of a typical open-shaped railway vehicle bogie frame, based on a computer dynamic simulation of a real operating environment, is carried out, and it is shown that this type of bogie is very sensitive to torsion, which suggests that the twist loading case should be carefully investigated if an open shape is involved in a particular bogie.

TL;DR: In this paper, classic cases of catastrophic brittle fracture in large welded structures so that those not in the field of structural integrity can understand the phenomenon of brittle fracture and some of its causes.

TL;DR: In this article, a crack growth model was developed, linking the limited load history data for the aircraft with the progression markings on the fracture surface, which were themselves complicated by the presence of stable tensile tearing which often occurs during crack growth.

TL;DR: In this article, failure modes of failed pin connections are considered in detail, including fatigue, ductile fracture, and stress corrosion cracking, where overload yielding or bore wear has removed the effectiveness of the hammer peened layer in the bore.

TL;DR: In this paper, the causes of the catastrophic failure of a gas-turbine aero engine which led to an air crash were examined and the failure was traced to the fatigue failure of the 1.5 mm diameter retaining ring made from AISI 304 stainless steel.

TL;DR: In this paper, the failures of six pressure vessels are described: Sizewell boiler (1963), John Thompson ammonia converter for ICI Immingham (1965), Cockenzie power station boiler drum (1966), Typpi Oy heat exchangers (1970), Robert Jenkins pressure vessel (1970) and the Union Oil Co. amine absorber tower (1984).

TL;DR: In this article, the authors used transparent polymer models which allow in situ photographs of the crack plane to determine the changes in crack shape as they grow from one leg of the double-T cross section into the wider portion of the specimen, and to determine whether crack growth could be delayed or arrested in this area.

TL;DR: In this paper, the characteristics and causes of the fatigue failure of a turbine blade, which was made of a K405 Ni-base superalloy, were analyzed. And the results showed that the blade fatigue failure is due to embrittlement, which is induced by the contamination of a Bi-Sn low melting point alloy on the blade surface during the manufacturing process of the blades, under the effects of service temperature and stress.

TL;DR: In this article, the authors proposed the use of an accelerated testing method, now commonly referred to as the rising load K~scc test, which is essentially identical to the procedure used for Kic fracture toughness testing, except that slower loading rates are used.

TL;DR: In this paper, the authors investigated the effect of stress relief features and unmodified joints in non-magnetic (austenitic) drill-collar connections using finite element stress analysis.

TL;DR: In this paper, the occurrence of premature leaks in vitreous enamel coated steel tanks was investigated and it was suspected that inadequate firing of the enamel coating was the cause of these pores.

TL;DR: In this article, the fatigue failure of a welded steel vessel in a chemical plant was described, where a pair of trunnion shafts was welded to opposite sides of the vessel.

TL;DR: In this article, a non-destructive technique to measure strain over small areas of specimens in the scanning electron microscope (SEM) is described, which can quantitatively estimate localized strains due to mechanically induced damage with very high strain and spatial resolution sensitivities in a nondestructive fashion.

TL;DR: In this paper, the leakage failure of a brake nave on a landing gear has been investigated and a crack initiating at the transitional region and propagating as deep as the blind gas hole was responsible for the leakage.

TL;DR: In this article, the service failure of a specific airshaft, from both fatigue crack initiation and crack propagation considerations, is discussed. And the failure might have easily been avoided.

TL;DR: In this article, a linear elastic fracture mechanics analysis, using measured fracture toughness values, and realistic estimates of the stress, indicated that the cast-in glazed defect was the most plausible explanation for the failure.

TL;DR: In this paper, the authors describe a practical case of the successful application of fracture mechanics principles to evaluate turbine blade integrity that led to the saving of a considerable sum of money in reserve energy and downstream economic advantages due to the avoidance of cutting the electricity supply.