Showing papers in "Engineering Failure Analysis in 2015"

TL;DR: In this paper, a review of the literature on the dynamics of cracked gear rotor systems is presented, which mainly focuses on three topics: crack propagation prediction, time-varying mesh stiffness (TVMS) calculation and vibration response calculation.

TL;DR: In this paper, a damaged boiler tube made of grade 20 -St.20 (or 20G, equivalent to AISI 1020) was investigated, and the experimental research was conducted in two distinctive phases: failure analysis of the boiler evaporator tube sample and subsequent postmortem analysis of viable hydrogen embrittlement mechanisms (HE) in St.20 steel.

TL;DR: In this article, a modified Hamming function is proposed to represent the effect of the transmission path of a planetary gearbox and the resultant vibration signals of the gearbox are analyzed.

TL;DR: Considering the effects of the extended tooth contact and tooth root crack on the time-varying mesh stiffness (TVMS), a finite element (FE) model of a spur gear pair in mesh is established by ANSYS software as mentioned in this paper.

TL;DR: In this article, the authors reviewed the concept of oil and gas transmission pipeline failures in a corrosive environment by highlighting the corrosion mechanisms, dominant stress corrosion cracking trends, hydrogen induced cracking and predominant models for burst pressure estimation.

TL;DR: In this paper, a detailed failure analysis of seven masonry churches, which were severely damaged during the 2012 Emilia-Romagna (Italy) seismic sequence, by means of 3D FE non-linear dynamic simulations is presented.

TL;DR: Li et al. as mentioned in this paper proposed a new battery mechanical integrity criteria based on the mechanical strength theory, by considering the strain rate and inertia effect of the battery structural and material, the dynamic mechanical behavior of lithium-ion battery is investigated.

TL;DR: In this article, Ma et al. presented an improved analytical model for the time-varying mesh stiffness (TVMS) calculation of cracked spur gears, and compared the IAM, traditional analytical model (TAM) and finite element (FE) model under different torques and crack depths.

TL;DR: The most suitable way to perform a fast but reliable failure analysis of existing masonry churches in earthquake prone areas is investigated in order to predict the state of damage and eventually failure modes as discussed by the authors.

TL;DR: In this paper, the effect of shaft misalignment and friction on total effective mesh stiffness for spur gear pair has been investigated and the results showed clearly that misal alignment and friction affect TVMS of gear pair.

TL;DR: In this article, the authors analyzed the fracture failure of a hard-thick sandstone main roof in a coal mine and found that the failure of the roof can cause strata pressure behaviors, rock-bursts and abnormal gas emissions, which may result in equipment damages and casualties.

TL;DR: In this paper, a multilayer perceptron (MLP) trained by a quasi-Newton approach was used to predict the failure frequency of a water utility in one Polish water utility.

TL;DR: In this article, a failure analysis of pre-stressed concrete members subjected to lateral impact loads using the finite element analysis (FEA) program, LS-DYNA, is presented.

TL;DR: In this paper, an analytical investigation of the influence of spatial crack propagation on the time-varying Gear Mesh Stiffness (GMS) and also the Load Sharing Ratio (LSR) is presented.

TL;DR: In this paper, the failure behavior and failure pressure of X80 pipelines with longitudinally and circumferentially aligned interacting corrosion defects based on nonlinear finite element method, X80 pipeline with single corrosion defect is studied as well.

TL;DR: In this paper, a series of high speed impact experiments were performed using an instrumented drop-weight impact machine to attain a better understanding of the failure behavior of reinforced concrete (RC) beams under impact load.

TL;DR: In this paper, a 3D nonlinear stress analysis model has been applied to estimate stress fields of the railway mono-block wheel in heat treatment process, and the model was then used to calculate stress intensity factors and fatigue life of railway wheel.

TL;DR: In this paper, the authors investigated the capability of advanced numerical modeling to address the aforementioned issues and to simulate the damage in complex masonry structures, such as the Poblet Monastery in Spain.

TL;DR: In this article, the authors investigated the stress concentration factors (SCFs) of isolated elliptical corrosion pits using 3-D finite element analyses and developed statistically predictive models based on least squares support vector machine (LS-SVM) realized in a ubiquitous spreadsheet platform.

TL;DR: In this article, a methodology for the seismic vulnerability assessment of all types of towers and slender unreinforced masonry structures (e.g., light houses and minarets) is presented.

TL;DR: In this paper, a failure analysis of water supply failure frequency in one of the cities in Poland is presented, where the average failure rate for the main pipelines is λ Mavg ǫ = 0.98, the distribution pipelines λ Ravg �= 0.42, and the water connections λ Pavg à 0.35, the majority of failures (45.62%) happen in the distribution pipeline, representing about 53% of the total length of the pipelines.

TL;DR: In this article, a micromechanical model is proposed to estimate fracture toughness based on the tensile strength of the solid material and the topology of the cellular structure of polyurethane foams.

TL;DR: In this paper, power transformer failures are analyzed and their root causes are systematically investigated in Tamil Nadu Transmission Corporation Limited and Tamil Nadu Generation and Distribution Corporation Limited (TANGEDCO) electric utilities, based on 196 failure cases from the year 2009-2013.

TL;DR: In this paper, an analytical model based on limit analysis is developed to describe the relative stability of pointed and basket-handle arches and portals with respect to circular ones, for varying geometry parameters.

TL;DR: In this article, a failure of a first stage compressor blade of a Gas Turbine Generator in a Gas Treatment plant caused severe mechanical damage to the compressor section and power supply troubles.

TL;DR: In this paper, a review of the multiple damage modes of plastic gears, including both general and plastic gear-exclusive modes, is provided, and a unique system of analysis of gear utilization perspectives that evaluates all possible damaging processes is built.

TL;DR: In this paper, a numerical simulation was conducted in ABAQUS, for the most commonly used PE pipe of DN110-SDR11, under the action of foundation settlement, and the situation that PE pipe is perpendicular to settlement section was considered.

TL;DR: In this article, the authors provide an overview on the assessment of fatigue life of marine engine crankshafts and its maintenance taking into account the design improving in the last decades, considering that accurate estimation of the fatigue life is very important to ensure safety of components and its reliability.

TL;DR: In this article, the authors analyzed the cracking failure of a new heat exchanger during first start-up operation and proved that the residual tensile stress due to seal expansion has been proved by numerical calculation.

TL;DR: In this article, a meso-scale mechanical model and method for the study on the failure behavior of concrete cover was built, where the non-uniform radial displacement distribution was adopted to simulate the corrosion expansion behavior of the rebar.