Analysis of Fatigue Life in High Temperature of W Pattern Sealing Rings Used in Aircraft Engine

2014 ◽  
Vol 496-500 ◽  
pp. 571-574
Author(s):  
Xi Chen ◽  
Yun Wang
Keyword(s):  
Finite Element ◽  
High Temperature ◽  
Fatigue Life ◽  
Cyclic Loading ◽  
Fatigue Test ◽  
Aircraft Engine ◽  
Finite Element Models ◽  
Flight Safety ◽  
Sectional Structure ◽  
High Temperature Gas

sealing rings used in aircraft engine are surrounded by high-temperature gas and cyclic loading when they are working. The reliability of its work directly affect flight safety and engines life. This paper framed some kind of W pattern sealing rings finite element models with different sectional structure size, first analyze them strength of structure in specific conditions, then simulate the fatigue life of them by using analysis methods of fatigue and parameters of fatigue test, finally we can get damage contours and fatigue life in high temperature of W pattern sealing rings theoretically, providing some theoretical reference of designing and manufacturing sealing rings.

Elastic-Plastic Finite Element Simulation and Fatigue Life Prediction for Beam and Elbow Under Cyclic Loading

2007 ◽  
Author(s):  
Xian-Kui Zhu ◽  
Brian N. Leis
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Cyclic Loading ◽  
Plastic Strain ◽  
Kinematic Hardening ◽  
Kinematic Model ◽  
Cyclic Plastic ◽  
Hardening Models ◽  
Critical Location ◽  
Cyclic Plastic Strain

Work hardening and Bauschinger effects on plastic deformation and fatigue life for a beam and an elbow under cyclic loading are examined using finite element analysis (FEA). Three typical material plastic hardening models, i.e. isotropic, kinematic and combined isotropic/kinematic hardening models are adopted in the FEA calculations. Based on the FEA results of cyclic stress and strain at a critical location and using an energy-based fatigue damage parameter, the fatigue lives are predicted for the beam and elbow. The results show that (1) the three material hardening models determine similar stress at the critical location with small differences during the cyclic loading, (2) the isotropic model underestimates the cyclic plastic strain and overestimates the fatigue life, (3) the kinematic model overestimates the cyclic plastic strain and underestimates the fatigue life, and (4) the combined model predicts the intermediate cyclic plastic strain and reasonable fatigue life.

Fatigue Performance of Concrete with Pre-Cracks in Tension-Compression Cycles

2014 ◽  
Vol 584-586 ◽  
pp. 1054-1061
Author(s):  
Jian Shen ◽  
Xiao Yun Liu ◽  
Lang Wu
Keyword(s):  
Fatigue Life ◽  
Fatigue Strength ◽  
Cyclic Loading ◽  
Fatigue Test ◽  
Stress Ratio ◽  
Fatigue Property ◽  
Fatigue Performance ◽  
Cycle Fatigue ◽  
Fatigue Load ◽  
Compression Cycle

A tension-compression cycle fatigue test was performed in order to study the fatigue property of C50 concrete with pre-cracks in cyclic loading. The stress ratio was-1 and the amplitude was 0.2 MPa ~1.30 MPa. The results show that the modified coefficient of fatigue strength is 0.198~0.265 and the infinite life fatigue strength is below 0.45MPa. While the log value of fatigue life is approximately linear with the amplitude of fatigue load stress, the discreteness of fatigue life, the particularity of concrete, has little to do with the amplitude. The S-N, P-N fatigue life curves and the constant fatigue life diagram of pre-crack concrete are obtained.

A Review of Haynes® 230 and Haynes 617 Alloys for High Temperature Gas Cooled Reactors

2007 ◽  
Author(s):  
Michael Katcher ◽  
Dwaine L. Klarstrom
Keyword(s):  
High Temperature ◽  
Fatigue Life ◽  
Fatigue Strength ◽  
Grain Boundary ◽  
Creep Strength ◽  
Thermal Fatigue ◽  
Low Cycle Fatigue ◽  
Carbide Precipitation ◽  
Cooling Rates ◽  
High Temperature Gas

HAYNES 230 and 617 alloys are competing for use on Generation IV, high temperature gas cooled reactor components because of their good high temperature creep strength in the temperature range of 760°C and 982°C and resistance to attack in the gas cooled reactor environment. A review of the metallurgy affecting the properties in each alloy is provided. It is shown that the grain size and carbide precipitation developed during manufacture affect short term and long term ductility, fatigue life, and creep strength. For example, 230 alloy has a finer grained structure which promotes fatigue strength with a slight sacrifice in creep strength. The 617 alloy has a coarser grain structure which provides slightly higher creep resistance while sacrificing some fatigue strength. Thermal aging also introduces gamma prime precipitation to 617 alloy in addition to grain boundary carbides. This, along with grain boundary oxidation, reduces the low cycle fatigue strength of 617 alloy compared to 230 alloy. Independent studies have shown that 230 alloy possesses higher resistance to thermal fatigue than 617 alloy. However, welds of both base metals with similar weld composition have about the same thermal fatigue life. Cooling rates from solution annealing temperatures during processing affect the ductility and creep strength of these alloys with the highest cooling rates preferred for retention of ductility and creep strength. Slow cooling rates promote carbide precipitation in the grain boundaries which reduces ductility and creep strength.

Scale Effects in the High Temperature Gas Pressure Forming of Electrodeposited Fine-Grained Copper Thin Sheet

2007 ◽  
Vol 551-552 ◽  
pp. 347-353
Author(s):  
K. Lei ◽  
Kai Feng Zhang ◽  
M.J. Tong
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
High Temperature ◽  
Scale Effects ◽  
Gas Pressure ◽  
Small Scale ◽  
Fine Grained ◽  
Experimental Values ◽  
High Temperature Gas ◽  
Element Method

Scale effects in the high temperature gas pressure forming of electrodeposited fine-grained copper thin sheets were investigated by a series of tests at various forming temperatures and die apertures. The average as-deposited copper grain size was 5 μm. The geometrical parameters of the bugling die system and the thickness of copper sheet varied in proportion. Different radius hemisphere parts from 0.5mm to 5mm were obtained at a strain rate of 5.0×10−4 s−1, which was controlled by pressure forces curves determined in terms of a finite element method (FEM) based on constitutive equation proposed by Backoften in 1964. The experimental relative bulging height (RBH) values were measured, and compared with that predicted by the same finite element method (FEM). It was found that the experimental values of large scale parts approach to simulated values, whereas the experimental values of small scale parts were quite different from simulated values. In order to explain these phenomena, a grain-rotation-weakened mechanism was proposed.

Application of CAE Systems in Forming of Drawpieces with Use Rubber-Pad Forming Processes / Zastosowanie Systemów CAE W Projektowaniu Procesów Tłoczenia Z Użyciem Odkształcalnych Narzędzi

2012 ◽  
Vol 57 (4) ◽  
pp. 1179-1187
Author(s):  
D. Woźniak ◽  
M. Głowacki ◽  
M. Hojny ◽  
T. Pieja
Keyword(s):  
Computer Simulation ◽  
Finite Element ◽  
Numerical Analysis ◽  
Computer Simulations ◽  
Strain Distribution ◽  
Aircraft Engine ◽  
Finite Element Models ◽  
Drawing Process ◽  
Deep Drawing Process ◽  
Rubber Pad Forming

This article shows example result of computer simulations supporting production process of bearing housing of aircraft engine. Verification of both deep drawing process project and tools design were carried out using finite element models implemented in eta/Dynaform 5.8.1 system and LS-DYNA solver. Wrinkling and fracture of the material were the main phenomena subjected to the investigation on the way of numerical analysis. A number of computer simulations were carried out in aim to analyze the deformation and strain distribution in the final product, as well as to eliminate the mentioned defects. In addition the comparison of results of both industrial tests and computer simulation was done.

scholarly journals Effect of Thermal Cyclic Loading on Stress-Strain Response and Fatigue Life of 3D Chip Stacking Structure

2020 ◽  
Author(s):  
Liang Zhang ◽  
Su-juan Zhong
Keyword(s):  
High Temperature ◽  
Fatigue Life ◽  
Cyclic Loading ◽  
Low Temperature ◽  
Dwell Time ◽  
Maximum Stress ◽  
Solder Joints ◽  
Stress Strain ◽  
3D Chip Stacking ◽  
Stacking Structure

Abstract In this paper, the thermo-mechanical reliability of IMCs (Ni3Sn4, Cu3Sn, Cu6Sn5) solder joints and Sn-3.9Ag-0.6Cu solder joints were investigated systematically in 3D chip stacking structure subjected to an accelerated thermal cyclic loading based on finite element simulation and Taguchi method. Effects of different control factors, including high temperature, low temperature, dwell time of thermal cyclic loading, and different IMCs on the stress-strain response and fatigue life of solder joints were calculated respectively. The results indicate that maximum stress-strain can be found in the second solder joint on the diagonal of IMC solder joints array, for Sn-3.9Ag-0.6Cu solder joints array the corner solder joints shows the obvious maximum stress-strain, these areas are the crack propagated locations. The stress-strain and fatigue life of solder joints is more sensitive to dwell temperature, especially to high temperature, increasing the high temperature, dwell time, or decreasing the low temperature, can reduce the stress-strain and enlarge the fatigue life of solder joints. The optimal design in the 3D IC structure has the combination of the Cu6Sn5/Cu3Sn, 373K high temperature, 233K low temperature, and 10min dwell time.

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