Mechanism of Foreign Object Damage and Investigating Effect of Particle Parameters on Erosion Rate of a Rough Surface Using Experimental and Numerical Methods

2015 ◽  
Vol 15 (2) ◽  
pp. 272-281 ◽  
Author(s):  
J. Kadkhodapour ◽  
A. Pourkamali Anaraki ◽  
B. Taherkhani
Keyword(s):  
Numerical Methods ◽  
Rough Surface ◽  
Erosion Rate ◽  
Foreign Object ◽  
Foreign Object Damage ◽  
Particle Parameters

scholarly journals Application of Design of Experiments to Foreign Object Damage on 7075-T6

2021 ◽  
Vol 31 ◽  
pp. 22-27
Author(s):  
Emanuele Vincenzo Arcieri ◽  
Sergio Baragetti ◽  
Željko Božić
Keyword(s):  
Design Of Experiments ◽  
Foreign Object ◽  
Foreign Object Damage

Computational investigation of foreign object damage sustained by environmental barrier coatings (EBCs) and SiC/SiC ceramic-matrix composites (CMCs)

2015 ◽  
Vol 11 (2) ◽  
pp. 238-272 ◽  
Author(s):  
Mica Grujicic ◽  
Jennifer Snipes ◽  
Ramin Yavari ◽  
S. Ramaswami ◽  
Rohan Galgalikar
Keyword(s):  
Gas Turbine ◽  
Ceramic Matrix ◽  
Turbine Engines ◽  
Gas Turbine Engines ◽  
Foreign Object ◽  
Barrier Coatings ◽  
Content Type ◽  
Environmental Barrier Coatings ◽  
Foreign Object Damage ◽  
Environmental Barrier

Purpose – The purpose of this paper is to prevent their recession caused through chemical reaction with high-temperature water vapor, SiC-fiber/SiC-matrix ceramic-matrix composite (CMC) components used in gas-turbine engines are commonly protected with so-called environmental barrier coatings (EBCs). EBCs typically consist of three layers: a top thermal and mechanical protection coat; an intermediate layer which provides environmental protection; and a bond coat which assures good EBC/CMC adhesion. The materials used in different layers and their thicknesses are selected in such a way that the coating performance is optimized for the gas-turbine component in question. Design/methodology/approach – Gas-turbine engines, while in service, often tend to ingest various foreign objects of different sizes. Such objects, entrained within the gas flow, can be accelerated to velocities as high as 600 m/s and, on impact, cause substantial damage to the EBC and SiC/SiC CMC substrate, compromising the component integrity and service life. The problem of foreign object damage (FOD) is addressed in the present work computationally using a series of transient non-linear dynamics finite-element analyses. Before such analyses could be conducted, a major effort had to be invested toward developing, parameterizing and validating the constitutive models for all attendant materials. Findings – The computed FOD results are compared with their experimental counterparts in order to validate the numerical methodology employed. Originality/value – To the authors’ knowledge, the present work is the first reported study dealing with the computational analysis of the FOD sustained by CMCs protected with EBCs.

Simulated Foreign Object Damage on Blade Aerofoils: Real Damage Investigation

2008 ◽  
Author(s):  
Pierangelo Duo´ ◽  
Christian Pianka ◽  
Andrej Golowin ◽  
Matthias Fueller ◽  
Roger Schaefer ◽  
...  
Keyword(s):  
Fatigue Strength ◽  
Numerical Models ◽  
Research Work ◽  
Experimental Simulation ◽  
Foreign Object ◽  
Foreign Object Damage ◽  
Special Cases ◽  
Hcf Strength ◽  
Residual Fatigue ◽  
The Impact

During operating service, gas turbine aero-engines can ingest small hard particles which typically produce damage to the aerofoils. If the damage found is a tear or a perforation at the leading edge, it is known as a Foreign Object Damage or FOD and this leads to a reduction of the subsequent High-Cycle-Fatigue (HCF) strength. The objective of research work in this area is to assess the effect of FOD on the residual fatigue strength of compressor blades and to provide predictive tools for engineering judgment. The methodology followed is normally to carry out experimental simulation of FOD, followed by fatigue tests to assess subsequent performance. To date, research related to fatigue following FOD events has concentrated on HCF loading and the impact geometry is frequently that of a sphere against a flat surface or the edge of a blade-like specimen. Both of these aspects do not correspond to the worst cases of real FOD. Here it is intended to investigate the effect of a V-notch geometry, which is more representative of severe FOD found in service. Alongside this, numerical models can be used to simulate the damage and to evaluate the residual stress field. In addition analytical model are used to predict the residual fatigue strength. The current work explains the development of a new rig impact test and discusses the improvements necessary to obtain a sufficient repeatability of the impacts. From the experience gained with a gas gun, an alternative method using a pistol and a barrel, capable of achieving the necessary velocity of simulated FOD, was developed. The applied velocity was in the range of 250m/s to 300m/s and a technique to describe the impact is here discussed. Furthermore the introduction of a high speed camera has allowed to have a complete description of the impact scene and to better understand the impact. The impacted blades were measured and HCF tested. As a result, this has produced a large scatter in the residual fatigue strength. The current method to describe a notch using a 2D approach, which was applied to several geometries of notches, is here critically reviewed. The proposed method would incorporate a more sophisticated method, which reconstruct the real geometry using optical measurement. This latter measurement can fully describe the 3D geometry, showing particularly zones inside the notch where compressive residual might appears. Tears and shear of the material can also be described by applying this technique. The findings are compared with the residual HCF strength and the results are compared to special cases of HCF to justify the results out of theoretical prediction.

Experimental Fatigue Analysis of Compressor Blades with Preliminary Defects

2016 ◽  
Vol 250 ◽  
pp. 263-269
Author(s):  
Lucjan Witek ◽  
Arkadiusz Bednarz ◽  
Feliks Stachowicz
Keyword(s):  
Growth Dynamics ◽  
Crack Size ◽  
Fatigue Analysis ◽  
Foreign Object ◽  
Resonant Vibrations ◽  
Propagation Process ◽  
Compressor Blades ◽  
Foreign Object Damage ◽  
Crack Propagation Process ◽  
Blade Tip

This work presents results of the experimental fatigue analysis of the compressor blades. In the investigations the blade with the V-notch (which simulates the foreign object damage) was considered. The notch was created by machining. The blades during the fatigue test were entered into transverse vibration. The crack propagation process was conducted in resonance conditions. During investigations both the amplitude of the blade tip displacement and also the crack length were monitored. As the results of presented investigations both the number of load cycles to crack initiation and also the crack growth dynamics in the compressor blade subjected to resonant vibrations were determined. In the work the influence of crack size on the resonant frequency was also investigated.

The Effect of Foreign Object Damage on Compressor Blade High Cycle Fatigue Strength

2017 ◽  
Author(s):  
Benjamin Hanschke ◽  
Thomas Klauke ◽  
Arnold Kühhorn
Keyword(s):  
Fatigue Strength ◽  
Service Sector ◽  
High Cycle Fatigue ◽  
Compressor Blade ◽  
Foreign Object ◽  
Cycle Fatigue ◽  
Stress Concentrations ◽  
Foreign Object Damage ◽  
Input Parameters ◽  
Aero Engines

For a considerable amount of time blade integrated disks (blisks) are established as a standard component of high pressure compressors (HPCs) in aero engines. Due to the steady requirement to increase the efficiency of modern HPCs, blade profiles get thinned out and aerodynamic stage loading increases. Ever since, aerofoil design has to balance structural and aerodynamic requirements. One particularity of aero engines is the possibility to ingest different kinds of debris during operation and some of those particles are hard enough to seriously damage the aerofoil. Lately, a growing number of blisk-equipped aero engines entered service and the question of foreign object damage (FOD) sensitivity relating to compressor blade high cycle fatigue (HCF) has emerged. Correct prediction of fatigue strength drop due to a FOD provides a huge chance for cost cutting in the service sector as on-wing repairs (e.g. borescope blending) are much more convenient than the replacement of whole blisks and corresponding engine strips. The aim of this paper is to identify critical FOD-areas of a modern HPC stage and to analyze the effects of stress concentrations — caused by FOD — on the fatigue strength. A process chain has been developed, that automatically creates damaged geometries, meshes the parts and analyses the fatigue strength. Amplitude frequency strength (af-strength) has been chosen as fatigue strength indicator owing to the fact, that amplitudes and frequencies of blade vibrations are commonly measured either by blade tip timing or strain gauges. Furthermore, static and dynamic stress concentrations in damaged geometries compared to the reference design were computed. A random variation of input parameters was performed, such as the radial damage position at blade leading edge and damage diameter. Based on results of the different samples, correlations of input parameters and the fatigue strength drop have been investigated. Evaluation shows a significant mode dependence of critical blade areas with a large scatter between drops in fatigue strength visible for mode to mode comparison. Keeping in mind the necessity of fast response times in the in-service sector, FOD sensitivity computations could be performed for all blade rows of the HPC — including the analysis of possible borescope blending geometries — in the design stage. Finally, the actual amplitude frequency levels (af-levels) of the modes excited during operation have to be appropriately taken into consideration. For example, a pronounced af-strength drop due to a FOD may not be critical for safe engine operations because the observed mode is excited by small af-levels during operation. Hence, the endurance ratio — a quotient of af-level and af-strength — is used as assessment criterion.

Effects of Mechanical Surface Treatment on Fatigue Failure in Ti-6Al-4V: Role of Residual Stresses and Foreign-Object Damage

2002 ◽  
Vol 404-407 ◽  
pp. 457-462 ◽  
Author(s):  
I. Altenberger ◽  
U. Noster ◽  
B.L. Boyce ◽  
J.O. Peters ◽  
Berthold Scholtes ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Surface Treatment ◽  
Fatigue Failure ◽  
Foreign Object ◽  
Foreign Object Damage ◽  
Mechanical Surface Treatment ◽  
Mechanical Surface

scholarly journals Foreign Object Damage to Fan Rotor Blades of Aeroengine Part I: Experimental Study of Bird Impact

2007 ◽  
Vol 20 (5) ◽  
pp. 408-414 ◽  
Author(s):  
Guan Yupu ◽  
Zhao Zhenhua ◽  
Chen Wei ◽  
Gao Deping
Keyword(s):  
Experimental Study ◽  
Rotor Blades ◽  
Foreign Object ◽  
Foreign Object Damage ◽  
Bird Impact

Computational simulation of the relaxation of local stresses due to foreign object damage under cyclic loading

2010 ◽  
Vol 224 (2) ◽  
pp. 41-50 ◽  
Author(s):  
T Davis ◽  
J Ding ◽  
W Sun ◽  
S B Leen
Keyword(s):  
Stress Relaxation ◽  
Kinematic Hardening ◽  
Computational Simulation ◽  
Fatigue Loading ◽  
Cyclic Fatigue ◽  
Foreign Object ◽  
Stress Concentrations ◽  
Foreign Object Damage ◽  
Stress Ratios ◽  
The Impact

In this study, the phenomenon of residual stress relaxation from foreign object damage (FOD) is numerically simulated using a hybrid explicit—implicit finite-element method. The effects of cycle fatigue loadings on stress relaxation were studied. FOD is first simulated by firing a 3mm cube impacting onto a plate made of titanium alloy Ti-6Al-4V at 200m/s. The FOD impact produces two distinct stress concentrations: one is compressive directly beneath the impact site; the other is tensile around the outer edge of the impact. The plate was then assumed to be subjected to a cyclic fatigue loading. The stress relaxation was investigated under a range of stress ratios and maximum applied stresses. Two different material models were considered for the simulations, namely an elastic—perfectly plastic model and a non-linear kinematic hardening model.

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