Fatigue failure of type 45 steel during high-frequency loading with an asymmetric cycle

1969 ◽  
Vol 1 (6) ◽  
pp. 612-616
Author(s):  
N. L. Pozen ◽  
B. A. Lyashenko ◽  
V. N. Semirog-Orlik
Keyword(s):  
Fatigue Failure ◽  
High Frequency ◽  
Asymmetric Cycle

scholarly journals Fatigue failure of regenerator screens in a high frequency Stirling engine

1987 ◽  
Author(s):  
D.R. Hull ◽  
D.L. Alger ◽  
T.J. Moore ◽  
C.M. Sheuermann
Keyword(s):  
Fatigue Failure ◽  
High Frequency ◽  
Stirling Engine

scholarly journals The Analysis and Resolution of a Fatigue Failure of a Low Pressure Turbine Blade Caused by the Excitation of a Bladed Disc Mode of Vibration

1997 ◽  
Author(s):  
Malcolm C. Staddon ◽  
Paul R. Box ◽  
Barry Barnett ◽  
Tony Horton ◽  
Geoff H. Ballans
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Turbine Blade ◽  
Fatigue Failure ◽  
Strain Gauge ◽  
High Frequency ◽  
Low Pressure ◽  
Dynamic Strain ◽  
Element Analysis ◽  
Low Pressure Turbine

A high cycle fatigue failure of a low pressure turbine blade was investigated. Strain gauge tests of a running engine indicated a high dynamic response of the blade at the nozzle passing frequency. This could be attributed to the excitation of a bladed disc mode of vibration. A Finite Element analysis of the low pressure turbine blades and discs, together with bench testing of the complete structure, confirmed the existence of a high frequency 2nd Nodal Diameter mode of vibration. The levels of dynamic strain determined through strain gauge tests were found to be sufficient enough to explain the failure at the given location. Having understood the problem, the situation was resolved through the use of Finite Element analysis with a short term modification to the original blade aerofoil to prevent the mode from being excited. An aero/mechanical re-design of both the low pressure turbine rotor and the stator was undertaken to resolve the problem by both returning the blade to avoid high frequency excitation, and also by reducing the forcing effect of the nozzle passing frequency. The new design has been validated through strain gauge tests and endurance tests. A further improvement in performance was also obtained.

Study on high frequency vibration-induced fatigue failure of antenna beam in a metro bogie

2021 ◽  
pp. 105976
Author(s):  
Xingwen Wu ◽  
Chenxi Xie ◽  
Kaicheng Liu ◽  
Shengchuan Wu ◽  
Zefeng Wen ◽  
...  
Keyword(s):  
Fatigue Failure ◽  
High Frequency ◽  
High Frequency Vibration ◽  
Antenna Beam

Acoustically Induced Vibration of Drums Excited by Rotating Machinery

2005 ◽  
Author(s):  
Itsuro Hayashi ◽  
Shijie Guo
Keyword(s):  
Fatigue Failure ◽  
High Frequency ◽  
Three Dimensional ◽  
Rotating Machinery ◽  
Coupled Analysis ◽  
Pressure Loading ◽  
High Frequency Region ◽  
One Dimensional ◽  
Material Fatigue ◽  
High Frequency Vibrations

Rotating machinery generates pressure pulsations, and the pulsations may cause severe vibrations of drums in high frequency region, resulting in material fatigue failure under certain conditions. Experiments and numerical simulations were performed to investigate the mechanism of the high frequency vibrations of the drums downstream of compressors. The results show that fatigue failure occurs when acoustic diametral modes of a drum are excited by pressure loading. In order to establish practical countermeasures against the vibrations, three-dimensional sound-structural coupled analysis as well as one-dimensional pulsation analysis were conducted. As a result, practical measures such as changing diameter, or thickness of the drums, applying restriction orifice are confirmed effective by using the approach proposed in this study. The validity of the simulation methods incorporating the sensitivity to the fluid conditions is shown.

INVESTIGATION OF FRETTING FATIGUE BEHAVIOR OF TI811 ALLOY AT ELEVATED TEMPERATURE

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5489-5494
Author(s):  
XIAO-HUA ZHANG ◽  
DAO-XIN LIU
Keyword(s):  
Fatigue Life ◽  
Elevated Temperature ◽  
Contact Pressure ◽  
Fatigue Failure ◽  
High Frequency ◽  
Driving Force ◽  
Fatigue Behavior ◽  
Failure Process ◽  
Failure Mechanisms ◽  
Fretting Fatigue

The fretting fatigue behavior of the Ti 811titanium alloy, as influenced by temperature, slip amplitude, and contact pressure, was investigated using a high-frequency fatigue machine and a home-made high-temperature apparatus. The fretting fatigue failure mechanisms were studied by observing the fretting surface morphology features. The results show that the sensitivity to fretting fatigue is high at both 350°C and 500°C. The higher the temperature is, the more sensitive the alloy is to fretting fatigue failure. Creep is an important factor that influences the fretting fatigue failure process at elevated temperature. The fretting fatigue life of the Ti 811 alloy does not change in a monotonic way as the slip amplitude and contact pressure increase. This is due to the fact that the slip amplitude affects the action of fatigue and wear in the fretting process, and the nominal contact pressure affects the distribution and concentration of the stress and the amplitude of fretting slip at the contact surface, and thus further influences the crack initiation probability and the driving force for propagation.

The Microstructure of Steatite (Protoenstatite)

1985 ◽  
Vol 43 ◽  
pp. 236-237
Author(s):  
W. E. Lee ◽  
A. H. Heuer
Keyword(s):  
High Frequency ◽  
Glass Ceramics ◽  
Magnesium Silicate ◽  
Beam Current ◽  
Glassy Matrix ◽  
Angle Of Incidence ◽  
X Ray ◽  
Mechanical And Electrical Properties ◽  
Argon Ions ◽  
High Temperature Polymorph

IntroductionTraditional steatite ceramics, made by firing (vitrifying) hydrous magnesium silicate, have long been used as insulators for high frequency applications due to their excellent mechanical and electrical properties. Early x-ray and optical analysis of steatites showed that they were composed largely of protoenstatite (MgSiO3) in a glassy matrix. Recent studies of enstatite-containing glass ceramics have revived interest in the polymorphism of enstatite. Three polymorphs exist, two with orthorhombic and one with monoclinic symmetry (ortho, proto and clino enstatite, respectively). Steatite ceramics are of particular interest a they contain the normally unstable high-temperature polymorph, protoenstatite.Experimental3mm diameter discs cut from steatite rods (∼10” long and 0.5” dia.) were ground, polished, dimpled, and ion-thinned to electron transparency using 6KV Argon ions at a beam current of 1 x 10-3 A and a 12° angle of incidence. The discs were coated with carbon prior to TEM examination to minimize charging effects.

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