Fatigue Life Prediction for Gas Turbine Bearing Under 3D Elastoplastic Mixed Lubrication Condition

2021 ◽  
Author(s):  
Yan Feng ◽  
Xiujiang Shi ◽  
Xiqun Lu ◽  
ZhuoYi Qiu ◽  
Wen Sun ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Fatigue Life ◽  
Gas Turbine ◽  
Life Prediction ◽  
High Speed ◽  
Mixed Lubrication ◽  
Real Surface ◽  
Heavy Load ◽  
Lubrication Performance ◽  
Turbine Bearing

Abstract Gas turbine bearings usually work in harsh lubrication environments, with typical characteristics such as high speed, high temperature, and heavy load. Severe working conditions bring micro-contacts in local areas between the bearing rolling elements and the rings. Stress concentration and plastic deformation may further occur between the contact pairs, which will reduce the fatigue life of the bearing. In order to predict bearing fatigue life accurately, in this study, the effects of the real surface roughness and plastic deformation of the bearing are considered, a three-dimensional(3D) elastoplastic mixed lubrication model for gas turbine bearing is established, the 3D dynamic elastoplastic stress calculations under the surface are conducted, and the relative fatigue life of the bearing is predicted. Based on the 3D elastoplastic mixed lubrication model for the bearing, the influences of speed, load, roughness and material hardening on lubrication performance and fatigue life are also studied, which would provide theoretical guidance for the lubrication design and life prediction of the gas turbine bearings.

Life Prediction Method of CC and DS Ni Base Superalloys Under High Temperature Biaxial Fatigue Loading

2010 ◽  
Vol 132 (11) ◽  
Author(s):  
Takashi Ogata
Keyword(s):  
Fatigue Life ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Life Prediction ◽  
Compressive Strain ◽  
Prediction Method ◽  
Strain Range ◽  
Fatigue Loading ◽  
Normal Strain ◽  
Biaxial Fatigue

Polycrystalline conventional casting (CC) and directionally solidified (DS) Ni base superalloys are widely used as gas turbine blade materials. It was reported that the surface of a gas turbine blade is subjected to a biaxial tensile-compressive fatigue loading during a start-stop operation, based on finite element stress analysis results. It is necessary to establish the life prediction method of these superalloys under biaxial fatigue loading for reliable operations. In this study, the in-plane biaxial fatigue tests with different phases of x and y directional strain cycles were conducted on both CC and DS Ni base superalloys (IN738LC and GTD111DS) at high temperatures. The strain ratio ϕ was defined as the ratio between the x and y directional strains at 1/4 cycle and was varied from 1 to −1. In ϕ=1 and −1. The main cracks propagated in both the x and y directions in the CC superalloy. On the other hand, the main cracks of the DS superalloy propagated only in the x direction, indicating that the failure resistance in the solidified direction is weaker than that in the direction normal to the solidified direction. Although the biaxial fatigue life of the CC superalloy was correlated with the conventional Mises equivalent strain range, that of the DS superalloy depended on ϕ. The new biaxial fatigue life criterion, equivalent normal strain range for the DS superalloy was derived from the iso-fatigue life curve on a principal strain plane defined in this study. Fatigue life of the DS superalloy was correlated with the equivalent normal strain range. Fatigue life of the DS superalloy under equibiaxial fatigue loading was significantly reduced by introducing compressive strain hold dwell. Life prediction under equibiaxial fatigue loading with the compressive strain hold was successfully made by the nonlinear damage accumulation model. This suggests that the proposed method can be applied to life prediction of the gas turbine DS blades, which are subjected to biaxial fatigue loading during operation.

Research on Commercial Vehicle Clutch Release Bearing Fatigue Life Prediction Model

2013 ◽  
Vol 423-426 ◽  
pp. 1853-1857
Author(s):  
Guo Liang Chen ◽  
Xiao Yang Chen
Keyword(s):  
Fatigue Crack ◽  
Fatigue Life ◽  
Prediction Model ◽  
Contact Stress ◽  
Life Prediction ◽  
High Speed ◽  
Commercial Vehicle ◽  
Smelting Process ◽  
Fatigue Life Analysis ◽  
Life Prediction Model

Commercial vehicle clutch release bearings working at high speed, strong vibration,high temperature, damp and easy pollution conditions. Fatigue life analysis is based on the release bearing rings or rolling body began to appear fatigue spalling, in which this kind of phenomenon is under cyclic stress. The contact stress distribution is not uniform, the contact stress is mainly concentrated near the surface; influenced by the geometry and physical properties and lubrication of the surface significantly. Contact between the two types of fatigue crack extension methods: fatigue crack surface under expansion and surface fatigue crack propagation. The surface crack growth mainly originated from two kinds of cases: crack caused by surface pre crack and contact between the two surface asperity each other. New life prediction model for the release bearing based on L-P theory and Tallian model ,in which influence factors of fatigue life is introduced on the smelting process, surface defect, surface roughness, residual stress, elastohydrodynamic lubrication oil film,environmental cleanliness, temperature, the effect of varying load characteristics and other factors of fatigue life. The results show that: the clutch release bearing life prediction model of new and more close to the real conditions of automobile clutch, provide the theory basis for the development of a new generation high-speed heavy-duty clutch release bearing of the commercial vehicle.

A New Finite Element Approach to Biaxial Fatigue Life Prediction in Gas Turbine Engine

2010 ◽  
Author(s):  
Wasim Tarar ◽  
M.-H. Herman Shen
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Gas Turbine ◽  
Life Prediction ◽  
Gas Turbine Engine ◽  
Constitutive Law ◽  
Fatigue Life Prediction ◽  
Turbine Engine ◽  
Number Of Cycles ◽  
Cycles To Failure

High cycle fatigue is the most common cause of failure in gas turbine engines. Different design tools have been developed to predict number of cycles to failure for a component subjected to fatigue loads. An energy-based fatigue life prediction framework was previously developed in recent research for prediction of axial and bending fatigue life at various stress ratios. The framework for the prediction of fatigue life via energy analysis was based on a new constitutive law, which states the following: the amount of energy required to fracture a material is constant. A finite element approach for uniaxial and bending fatigue was developed by authors based on this constitutive law. In this study, the energy expressions that construct the new constitutive law are integrated into minimum potential energy formulation to develop a new QUAD-4 finite element for fatigue life prediction. The newly developed QUAD-4 element is further modified to obtain a plate element. The Plate element can be used to model plates subjected to biaxial fatigue including bending loads. The new QUAD-4 element is benchmarked with previously developed uniaxial tension/compression finite element. The comparison of Finite element method (FEM) results to existing experimental fatigue data, verifies the new finite element development for fatigue life prediction. The final output of this finite element analysis is in the form of number of cycles to failure for each element in ascending or descending order. Therefore, the new finite element framework can predict the number of cycles to failure at each location in gas turbine engine structural components. The new finite element provides a very useful tool for fatigue life prediction in gas turbine engine components. The performance of the fatigue finite element is demonstrated by the fatigue life predictions from Al6061-T6 aluminum and Ti-6Al-4V. Results are compared with experimental results and analytical predictions.

Influence of recess shape on comprehensive lubrication performance of high speed and heavy load hydrostatic thrust bearing

2019 ◽  
Vol 71 (2) ◽  
pp. 301-308
Author(s):  
Mubing Yu ◽  
Xiaodong Yu ◽  
Xuhang Zheng ◽  
Hang Qu ◽  
Tengfei Yuan ◽  
...  
Keyword(s):  
High Speed ◽  
Thrust Bearing ◽  
Great Influence ◽  
Constant Flow ◽  
Heavy Load ◽  
Content Type ◽  
Lubrication Performance ◽  
Improved Performance ◽  
Volume Method ◽  
Selection Of

Purpose This paper aims to describe a theoretical and experimental research concerning influence of recess shape on comprehensive lubrication performance of high speed and heavy load hydrostatic thrust bearing with a constant flow. Design/methodology/approach The lubrication performance of a hydrostatic thrust bearing with different recess shape under the working conditions of high speed and heavy load has been simulated by using computational fluid dynamics and finite volume method. Findings It is found that the comprehensive lubrication performance of a hydrostatic thrust bearing with circular recess is optimal. The results demonstrate that recess shape has a great influence on the lubrication performance of the hydrostatic thrust bearing. Originality/value The simulation results indicate that to get an improved performance from a hydrostatic thrust bearing with constant flow, a proper selection of the recess shape is essential.

A New Hex-8 Finite Element for Gas Turbine Engine Fatigue Life Prediction

2011 ◽  
Author(s):  
Wasim Tarar ◽  
M.-H. Herman Shen
Keyword(s):  
Finite Element ◽  
Fatigue Life ◽  
Gas Turbine ◽  
Life Prediction ◽  
Gas Turbine Engine ◽  
Constitutive Law ◽  
Fatigue Life Prediction ◽  
Turbine Engine ◽  
Number Of Cycles ◽  
Cycles To Failure

High cycle fatigue is the major governing failure mode in aerospace structures and gas turbine engines. Different design tools are available to predict number of cycles to failure for a component subjected to fatigue loads. An energy-based fatigue life prediction framework was previously developed in recent research for prediction of axial, bending and torsional fatigue life at various stress ratios. The framework for the prediction of fatigue life via energy analysis was based on a new constitutive law, which states the following: the amount of energy required to fracture a material is constant. A 1-D ROD element for unixial fatigue, a BEAM element for bending fatigue and a QUAD-4 element for biaxial fatigue were developed by authors based on this constitutive law. In this study, the energy expressions that construct the new constitutive law are integrated into minimum potential energy formulation to develop a new HEX-8 BRICK finite element for fatigue life prediction. The newly developed HEX-8 BRICK element has 8 nodes and each node has 3 degrees of freedom (DOF) in x, y and z directions. This element is further modified to add the rotational and bending DOFs for application to real world three dimensional (3D) structures and components. HEX-8 BRICK fatigue finite element has capability to predict the number of cycles to failure for 3-D objects subjected to multiaxial stresses. The new HEX-8 element is benchmarked with previously developed uniaxial tension/compression finite element in order to verify the new development. The comparison of finite element method (FEM) results to existing experimental fatigue data, verifies the new finite element development for fatigue life prediction. The final output of this finite element analysis is in the form of number of cycles to failure for each element in ascending or descending order. Therefore, the new finite element framework can predict the number of cycles to failure at each location in gas turbine engine structural components. The new finite element provides a very useful tool for fatigue life prediction in gas turbine engine components as it provides a complete picture of fatiguing process. The performance of the HEX-8 fatigue finite element is demonstrated by comparison of life prediction results for A16061-T6 to previously developed multiaxial fatigue life prediction approach by the authors. Another set of comparison is made to results for type 304 stainless steel data.

Sign in / Sign up

Export Citation Format

Share Document