Showing papers in "Engineering Failure Analysis in 2014"

TL;DR: In this article, the authors review the historic development of cements and concrete and focus on the mechanical response of concrete and reinforced concrete to its working environment, using case study input to illustrate or highlight principal themes.

TL;DR: Considering the misalignment of gear root circle and base circle and accurate transition curve, an improved mesh stiffness model for a healthy gear pair is proposed and validated by the finite element method as mentioned in this paper.

TL;DR: In this article, an improved time-varying mesh stiffness algorithm is presented to simulate the vibration response of a gear-rotor system with tooth crack and the effects of geometric transmission error (GTE), bearing stiffness, and gear mesh stiffness on the dynamic model are analyzed.

TL;DR: In this paper, the authors exhaustively reviewed the failure mechanisms of three commonly used railway sleepers, namely, timber, concrete, and steel, and suggested solutions to minimise these problems.

TL;DR: In this paper, the authors present an overview of the four main failure modes of the Tala hydropower plant in Bhutan and discuss the recommended methods to prevent/mitigate against these failure modes.

TL;DR: In this article, the authors propose a descriptive model of the wear evolution process in rolling bearings over the whole lifetime, which uses a wide range of empirical findings in the literature to describe the wear interactions and evolution in the five-stage scenario: running-in, steadystate, defect initiation, defect propagation, and damage growth.

TL;DR: In this paper, the authors proposed a method for the calculation of friction excitations and contact stiffness based on the time-varying length of contact line in helical gears with tooth spalling defect.

TL;DR: In this article, the authors describe the problems concerning turbine rotor blade vibration that seriously impact the structural integrity of a developmental aero gas turbine, where the blades are fabricated from nickel base super alloy through directionally solidified investment casting process.

TL;DR: In this paper, the authors performed numerical simulation of antiknock performance and failure modes of concrete gravity dams under blast loading, where the authors analyzed the effects of mesh size, some interesting conclusions regarding the mesh size for actual events are obtained.

TL;DR: In this article, it was shown that during a very short operation of a steel rope in a hoist system of a drilling rig, the wires of the upper layer of cable strands were damaged.

TL;DR: In this paper, a 52.3-m composite blade designed for multi-megawatt wind turbines was found to exhibit multiple failure modes and delamination of unidirectional laminates in the spar cap was identified as the plausible root cause of the blade failure.

TL;DR: In this article, a fully coupled numerical approach with combined Lagrangian and Eulerian methods, incorporating the explosion processes, is performed to model the concrete material behavior subjected to blast loading.

TL;DR: In this paper, a complete corrective maintenance scheme for engineering equipment is proposed, where the FMECA is extended to organize the numerous failure modes and the failure propagation model (FPM) is presented to depict the cause-effect relationship between failures.

TL;DR: In this article, a three-dimensional nonlinear stress analysis model has been applied to estimate stress fields of the railway mono-block wheel in heat treatment process, and the results show good agreement with those achieved in field measurements.

TL;DR: In this article, the authors presented the results obtained by examining 616 crankshaft bearings, damaged by different mechanisms, and performed a fault tree analysis to determine the root causes for engine bearing failures.

TL;DR: In this paper, an algorithm with a new sensitivity vector for reliability analysis is presented in reliability analysis, the sensitivity vector is computed using the conjugate gradient vector of limit state function based on Hasofer-Lind and Rackwitz-Fiessler (HL-RF) method (CHL-RF algorithm).

TL;DR: In this article, the authors studied the thermal fatigue damage of AISI H13 tool steels that underwent different heat treatments and found that the thermal resistance is closely related to the initial hardness.

TL;DR: In this article, the authors focused on ultimate strength, structural safety assessment, and collapse of masonry domes, and carried out research targeted at reducing the incidence and severity of structural failures in cultural buildings.

TL;DR: In this article, the feasibility of hybridizing a magnetic arrangement in the conventional journal bearing system has been experimented for the operating conditions of heavy load and slow speed, and the results of the experimental investigations in terms of the weight loss (wear), reduction in the magnetic flux density, acceleration signals and photographs of worn & fractured rotor are reported.

TL;DR: In this paper, the influence of concrete meso-structure on the failure pattern of concrete cover is accounted for and the simulation results have a good agreement with the available test data and they are between the two analytical results.

TL;DR: In this paper, a prognostic method is presented for fault detection in gears and bearings in wind turbine drivetrains, based on angular velocity measurements from the gearbox input shaft and the output to the generator.

TL;DR: In this paper, the authors investigated the quantitative correlation between the stress state and geometric features of a corrosion pit idealized as a semi-ellipsoidal pit and found that the maximum possible SCF is independent of Rd and increases linearly with Rs.

TL;DR: In this paper, a combined criterion based on volumetric method and stress triaxiality is proposed for assessment of pipelines containing a gouge and dent defect, which does not reduce the burst pressure of A37 steel pipelines.

TL;DR: In this paper, the authors propose a general safety-diagnosability principle for supporting accident prevention, which requires that all safety-degrading events or states that defense-in-depth is meant to protect against be diagnosable, and that breaches of safety barriers be unambiguously monitored and reported.

TL;DR: In this article, a fatigue life assessment review of failure pipeline steels is presented, where stress-life, strain-life and linear elastic fracture mechanics crack propagation method has shown to be well accepted as a benchmark model of fatigue assessment.

TL;DR: In this article, the fatigue life properties of low carbon grey cast iron (EN-GJL-250), which is widely used for automotive brake discs, were evaluated at room temperature (RT) and at brake discs' working temperatures: 500°C, 600°C and 700°C.

TL;DR: In this paper, diagnostic of fatigue damage in reinforced concrete (RC) beams using acoustic emission (AE) technique was investigated based on severity analysis of AE signal strength during service life of the beams, bath-tub curves derived from AE signal are presented and divided into three stages; burn-in, steady state and burnout.

TL;DR: In this article, the authors investigated the mechanical behavior of bricks subjected to moisture and salt crystallization, and aimed at determining the mechanical degradation of bricks due to these environmental factors, and provided novel information about the effects of moisture and salts on the compression strength of bricks.

TL;DR: In this paper, the authors determined the dependence among the weight of sharp material falling on the conveyor belt, shatter height and force conditions in the belt on the base of experimental measurements by the help of regression mathematical model and determined conditions under which the belt is damaged.

TL;DR: In this paper, the failure of the stage I, II and III turbine rotor blades of an aircraft engine was investigated by metallurgical analysis of the failed/damaged blades, which were made out of Ni-based superalloys of different grades.