Showing papers in "Engineering Failure Analysis in 1998"

TL;DR: In this article, the distribution of component failures is discussed, as well as the causes thereof, and case studies are presented to give insight in the methodology of failure analysis of automotive components, and the valuable information which can be gained thereby.

TL;DR: In this paper, an analysis of the failure of turbine blades of a 210 MW thermal power plant has been presented, where failure of the brazed joints between the blade and lacing rod was found to be due to improper brazing operations and corrosion effects during service.

TL;DR: In this article, the authors investigated the effect of atmospheric water and chlorides on the cracking of cold-drawn stress relieved prestressing wire in a prestressed reinforced-concrete structure due to a winter salting of the road pavements of a motorway viaduct in Slovenia.

TL;DR: In this article, the details of two failures of prestressed steel bars are reported and a failure analysis is carried out using Linear Elastic Fracture Mechanics: the fracture toughness was measured using two standardized procedures and the pertinent stress intensity factor computed by numerical methods.

TL;DR: In this article, an investigation was carried out on a failed wheel-drive shaft component used on an unmanned, remotely operated vehicle for manoeuvring military targets, and the results confirmed the importance of recognizing in advance the salient factors leading to fatigue and the necessity in paying adequate attention to detail during design and manufacture if long service life is to be achieved.

TL;DR: In this article, the failure analysis of an air crash conclusively shows that the cage of the central main bearing of the compressor region failed due to fatigue, and the broken piece of the cage got struck between the bearing balls and the races.

TL;DR: In this article, the authors used the DC voltage gradient (DCVG) method to locate coating defects on underground pipelines and found that more than 80% of defects located after pipelaying were due to mechanical damage during construction.

TL;DR: In this article, the failure of a weld repaired turbine casing after 30 years of total service, including 5 years after weld repair, was analyzed. And the cracks might have initiated from the voids present in the weld region possibly by thermal fatigue mechanism.

TL;DR: In this article, the benefits of using the fluoride ion cleaning (FIC) process at sub-atmospheric pressure were highlighted. But, the authors did not consider the performance of the brazed repaired cracks under mechanical and thermal loading.

TL;DR: In this article, a new time domain based formulation has been developed to control multi-axis servo-hydraulic simulator control, which averts the need for Fast Fourier Transform (FFT) analysis.

TL;DR: In this article, a detailed failure investigation of copper tubes from a cold water distribution system which had failed due to pitting whilst in service was conducted, and the tubes were found to be made from phosphorus de-oxidised copper and no anomalies were evident in either the chemical composition or microstructure which could have caused the pitting observed.

TL;DR: In this paper, the functional failure of a concrete-lined steel sewage pipe was investigated and the underlying cause of the failure may be traced to a lack of sufficient backfill stiffness.

TL;DR: In this article, the authors investigated the cause of a series of malfunctions involving the bending or breaking of main steam turbine throttle valve spindles which occurred at service times ranging from hundreds to several thousand hours in a number of 270 MW steam raising units.

TL;DR: In the Piper Alpha disaster, the initial explosion in module C destroyed the firewall between modules C and B, and fragments caused secondary damage which lead to a fire as discussed by the authors, and the analysis is based on hand calculation of idealised elastic and elastic-plastic models.

TL;DR: In this article, an examination of a fifth wheel coupling which had failed in service showed that it had been modified and that the operating handle had been moved from its original design position, which completely eliminated the safety device designed to prevent inadvertent opening of the coupling locking mechanims.

TL;DR: In this article, an electronics firm experienced difficulty attaching gold metalized alumina ceramic plates to gold plated Kovar® alloy assemblies using gold germanium eutectic solder.

TL;DR: In this article, the effects caused by the detonation of chemical explosives in a subgrade under a cement concrete runway were modelled and a series of possible materials that could be used to fill and stabilise the camouflet to effect a rapid and long-term runway repair.

TL;DR: Failure analyses of various engine and airframe components from South African Air Force aircraft have been performed by the Division of Materials Science and Technology over several years and these have ranged from crash investigations to minor problems encountered during routine maintenance.

TL;DR: In this article, a flexible waveguide was found to have a green contaminating residue on brass and copper sections caused by exposure of the plating to nitric acid, and it was suggested that the waveguide be plated with a more corrosion resistant metal such as rhodium.

TL;DR: In this article, the authors highlight the trend recently observed in service exposed (38 years) plain carbon steels used as reactor and distillation column materials in a petrochemical industry.

TL;DR: In this paper, a finite element analysis of annular and offset annular plates with holes is presented, which allows one to test the theory available for these cases, as well as the use of the finite element method itself.

TL;DR: In this paper, an experimental stress analysis was undertaken by strain gauging the actual shaft of an actuator in situ and measuring the bending, tension and torsional stresses in operation during rotation, and valve closure.

TL;DR: In this paper, the effect of long-term hydrogenation of the (Sm,Dy,Gd)Co 5 permanent magnet on mechanical degradation and decay of magnetic properties in service is investigated.

TL;DR: In this paper, the premature failure of a high strength low alloy steel (HSLA) pressure chamber has been analyzed using standard metallographic and failure analysis techniques, and the welding defect had grown into a semi-elliptical surface crack during the fabrication process of the pressure chamber.

TL;DR: In this article, the authors present a case study dealing with the operational failure of an impulse line used to connect a crude oil pipeline header to a pressure transmitter in an oil field booster station.

TL;DR: In this paper, the authors investigated failures in connectors of compressor suction and discharge lines in roof mounted package air conditioners designed for use in passenger coaches of Indian Railways and concluded that resonance between the discharge line and the first harmonic of the compressor excitation frequency was the cause of failure in this line.

TL;DR: In this article, it was shown how the changes that had been made to the initial design and processing of the actuators were not entirely compatible with each other and reduced the metallurgical safety factor.

TL;DR: In this article, a stainless steel chemical hood was found to be corroded when exposed to vapors from nitric and hydrochloric acids, and a repair methodology was presented, and alternative materials for new hoods were recommended.

TL;DR: In this article, the analysis of a failure of conveyor chain pins that had operated for only six weeks was presented. The pins had been heat treated so that they had become susceptible to hydrogen embrittlement, and had cracked.

TL;DR: In this article, a hydraulic-cylinder gland system used in aircraft failed by leaking because the hold-down bolts broke in the course of a trial run, and the fracture surface and the stress calculations for the bolts were described.