Fatigue Reliability Analysis of Turbine of Turbocharger Based on the Endurance Test Profile of Engine

2012 ◽  
Vol 215-216 ◽  
pp. 750-753
Author(s):  
Wang Zheng ◽  
Wei Dong Xing ◽  
A Na Wang ◽  
Li Xin
Keyword(s):  
Fatigue Life ◽  
Reliability Analysis ◽  
Failure Mode ◽  
Fatigue Failure ◽  
Fatigue Reliability ◽  
Endurance Test ◽  
Cycle Number ◽  
Operating Modes ◽  
Critical Location ◽  
The Relationship

For the fatigue failure mode of turbine of turbocharger for vehicle application, the method for fatigue reliability analysis and fatigue life prediction of turbine is studied based on the endurance test profile of engine. Firstly, the critical location of turbocharger turbine with fatigue failure mode is determined. Then, the fatigue stress process of turbine is calculated according to the main operating modes consisted of the endurance test profile of engine. The fatigue strength of critical location of turbine with fatigue failure mode is studied through the fatigue test of imitation specimen, and the relationship between the fatigue life of turbine and stress is developed. Further, according to the endurance test profile of engine, the reliability model of turbine with fatigue failure mode is developed, and the rule that the reliability of turbine with fatigue failure mode changes as the cycle number of endurance test of engine is studied. Finally, the method for determining the reliable fatigue life of turbine is proposed.

An Efficient Methodology for Fatigue Reliability Analysis for Mechanical Components

2005 ◽  
Vol 128 (3) ◽  
pp. 293-297 ◽  
Author(s):  
Young Ho Park ◽  
Jun Tang
Keyword(s):  
Fatigue Life ◽  
Reliability Analysis ◽  
Fatigue Failure ◽  
Failure Modes ◽  
Random Variable ◽  
Theoretical Background ◽  
Fatigue Reliability ◽  
Reliability Factor ◽  
Mechanical Components ◽  
Variable Problem

This paper presents an efficient methodology to solve a fatigue reliability problem. The fatigue failure mechanism and its reliability assessment must be treated as a rate process since, in general, the capacity of the component and material itself changes irreversibly with time. However, when fatigue life is predicted using the S-N curve and a damage summation scheme, the time dependent stress can be represented as several time-independent stress levels using the cycle counting approach. Since, in each counted stress cycle, the stress amplitude is constant, it becomes a random variable problem. The purpose of this study is to develop a methodology and algorithm to solve this converted random variable problem by combining the accumulated damage analysis with the first-order reliability analysis (FORM) to evaluate fatigue reliability. This task was tackled by determining a reliability factor using an inverse reliability analysis. The theoretical background and algorithm for the proposed approach to reliability analysis will be introduced based on fatigue failure modes of mechanical components. This paper will draw on an exploration of the ability to predict spectral fatigue life and to assess the corresponding reliability under a given dynamic environment. Next, the process for carrying out this integrated method of analysis will be explained. Use of the proposed methodology will allow for the prediction of mechanical component fatigue reliability according to different mission requirements.

Analysis of Fatigue Reliability and Fatigue Life for a High Voltage Valve

2012 ◽  
Vol 479-481 ◽  
pp. 2072-2075
Author(s):  
Ji Kang Bo
Keyword(s):  
Fatigue Life ◽  
Service Life ◽  
Failure Mode ◽  
Fatigue Damage ◽  
Fatigue Failure ◽  
High Voltage ◽  
Failure Probability ◽  
Fatigue Reliability ◽  
Actual Application ◽  
Working Principle

The high voltage valve bears repeated loads and impact in its working state. Fatigue failure or fatigue damage is the most common failure mode of high voltage valves. This work analyzes the working principle and working characteristics of a high voltage valve under a static rated load, and proposes the necessity of the fatigue analysis. The failure probability of the high voltage valve is presented and the service life of the entire valve obtained. To find the part prone to fail, the evaluation of the fatigue life of the high voltage valve is carried out. The fatigue life and safety factor of the high voltage valve is obtained. It is found that the edge joints are easy to fatigue failure, which provides a reference for the actual application and of maintenance the high voltage valve.

ANN-Based Structure Optimization with Fatigue Reliability Constrains

2012 ◽  
Vol 204-208 ◽  
pp. 3128-3131
Author(s):  
Li Rong Sha ◽  
Yue Yang
Keyword(s):  
Structural Optimization ◽  
Objective Function ◽  
Reliability Analysis ◽  
Response Surface ◽  
Minimum Weight ◽  
Structure Optimization ◽  
Fatigue Reliability ◽  
Ann Model ◽  
Surface Method ◽  
The Relationship

The ANN-based optimization for considering fatigue reliability requirements in structural optimization was proposed. The ANN-based response surface method was employed for performing fatigue reliability analysis. The fatigue reliability requirements were considered as constraints while the weight as the objective function, the ANN model was adopted to establish the relationship between the fatigue reliability and geometry dimension of the structure, the optimal results of the structure with a minimum weight was reached.

Fatigue Reliability Analysis Including Super Long Life Regime

2010 ◽  
Vol 118-120 ◽  
pp. 17-26 ◽  
Author(s):  
Yong Xiang Zhao
Keyword(s):  
Fatigue Life ◽  
Reliability Analysis ◽  
Life Prediction ◽  
Reliability Assessment ◽  
Cyclic Stress ◽  
Fatigue Life Prediction ◽  
Fatigue Reliability ◽  
Stress Strain ◽  
Structural Fatigue ◽  
Long Life

For an engineering structure with an actual fatigue life over that corresponding to a so-called fatigue limit, appropriate reliability assessment and fatigue life prediction are essential for developing the structure and sustaining its high quality in service. Basic clues are explored. A competition fatigue initial mechanism is shown to provide a requirement of material primary quality management. Affordable deduced material and structural probabilistic S-N curves are presented by fitting into material mid-and-long life S-N data and fatigue limits and, then, comparing to structural fatigue limits. Random cyclic stress-strain relations are depicted for constructing random stressing history of structures. Reliability assessment and fatigue life prediction are established to synthetically consider the interference of applied stresses deduced from the random cyclic stress-strain relations and capacity strengths derived from the structural S-N relations with an expected life. Affordable and appropriate method has been then developed to realize the reliability assessment and fatigue life prediction including the super long life regime. Availability of the present method has been indicated through a reliability analysis to the velocity related reliabilities and fatigue lives of a railway axle.

scholarly journals Fatigue Reliability Analysis Method of Reactor Structure Considering Cumulative Effect of Irradiation

Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 801
Author(s):  
Bo Sun ◽  
Junlin Pan ◽  
Zili Wang ◽  
Yi Ren ◽  
Dariusz Mazurkiewicz ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Reliability Analysis ◽  
Life Prediction ◽  
Cumulative Effect ◽  
Neutron Dose ◽  
Design Parameters ◽  
Performance Parameters ◽  
Analysis Method ◽  
Fatigue Reliability ◽  
Rate Of Increase

The influence of irradiation should be considered in fatigue reliability analyses of reactor structures under irradiation conditions. In this study, the effects of irradiation hardening and irradiation embrittlement on fatigue performance parameters were quantified and a fatigue life prediction model was developed. Based on this model, which takes into account the cumulative effect of a neutron dose, the total fatigue damage was calculated according to Miner’s linear cumulative damage law, and the reliability analysis was carried out using the Monte Carlo simulation method. The case results show that the fatigue life acquired by taking into account the cumulative effect of irradiation was reduced by 24.3% compared with that acquired without considering the irradiation effect. Irradiation led to the increase of the fatigue life at low strains and its decrease at high strains, which is in accordance with the findings of an irradiation fatigue test. The rate of increase in the fatigue life decreased gradually with the increase of the neutron dose. The irradiation performance parameters had a small influence on fatigue reliability, while the fatigue strength coefficient and the elastic modulus had a great influence on the fatigue reliability. Compared with the current method, which uses a high safety factor to determine design parameters, a fatigue reliability analysis method taking into account the cumulative effect of irradiation could be more accurate in the reliability analysis and life prediction of reactor structures.

Estimation of Probability of Fatigue Failure on Tubular Joints

2021 ◽  
Author(s):  
N. Lokesh ◽  
S. Nallayarasu ◽  
S. Karunanithi
Keyword(s):  
Fatigue Life ◽  
Failure Mode ◽  
Fatigue Failure ◽  
Limit State ◽  
Probabilistic Approach ◽  
Fatigue Crack Initiation ◽  
High Stress ◽  
State Function ◽  
Reliability Method

Abstract Fatigue is generally considered the most critical failure mode in mechanical and structural systems. Due to high-stress concentrations, welded joints represent the most common fatigue crack initiation in steel structures susceptible to fatigue. In India, especially in western offshore, there are about 300 platforms, and 50% of them have reached their design life but still operating due to existing oil and gas reserves. Fatigue prediction in offshore structures is an extremely complicated process involving many factors such as complicated geometry, material, loading, and environment. These uncertainties are modelled as random variables. The assessment of failure probabilities takes a basis to formulate a limit state function for the relevant failure mode and deterioration mechanisms. The fatigue failure assessment based on a simplified probabilistic approach using the application of reliability-based procedures such as the First Order Reliability Method (FORM) is a useful tool. In the simplified fatigue assessment method, the two-parameter Weibull distribution is used to model the long-term distribution of fatigue stresses. Reliability of tubular joint using known fatigue life is an important factor in decision making for life extension of aged platforms. The methodology adopted in this study uses the linear damage accumulation model of Palmgren-Miner, double slope S-N curve, and one-to-one transformation of the probability density functions of long-term stress range and uncertainties to obtain the probability of fatigue failure as a function of the service life from known fatigue life.

An Efficient Algorithm Based on First Order Reliability Method for Fatigue Reliability Analysis of Mechanical Components

2002 ◽  
Author(s):  
Jun Tang ◽  
Young Ho Park
Keyword(s):  
Fatigue Life ◽  
Reliability Analysis ◽  
Search Algorithm ◽  
Strain History ◽  
Fatigue Reliability ◽  
First Order Reliability Method ◽  
Reliability Factor ◽  
First Order ◽  
Reliability Method ◽  
Mechanical Components

The method for fatigue reliability analysis of mechanical components using the First-Order Reliability Method (FORM) reconciles accuracy and efficiency requirements for random process reliability problems under fatigue failure. However, the algorithm for solving FORM is still complex and time consuming. In this paper, the FORM that utilizes an efficient search algorithm is proposed for reliability assessment of the strain-based fatigue life. Using the proposed method, a family of reliability-defined ε-Nf curves, referred to as R-ε-Nf curves, is constructed. An empirical mean stress modified strain-life equation is also used as the performance function. The primary focus of this effort has been the implementation of the new algorithm of FORM to define reliability factors used in modifying the conventional ε-Nf curve to create a family of R-ε-Nf curves, based on the unique reliability factor rule. The proposed method employs the inverse FORM algorithm to achieve computational results, including reliability and the corresponding fatigue life. The method enables the application of fatigue life design for a given cyclic stress and/or strain history. A numerical example is presented to demonstrate the proposed method.

Optimum Replacement Interval for Mechanical Components Based on Fatigue Reliability

2006 ◽  
Vol 129 (4) ◽  
pp. 683-688 ◽  
Author(s):  
Young H. Park ◽  
Jun Tang
Keyword(s):  
Decision Making ◽  
Fatigue Life ◽  
Fatigue Failure ◽  
Wide Band ◽  
Mean Value ◽  
Cumulative Damage ◽  
Fatigue Reliability ◽  
Damage Distribution ◽  
Mean And Variance ◽  
Mechanical Components

This paper introduces a maintenance decision-making strategy in the general area of replacement and reliability of mechanical components. The decision-making strategy involves the optimization of replacement interval calculated from fatigue failure of mechanical components. The proposed approach is based on the cumulative damage distribution function for evaluating mean fatigue life. Using this approach, the analytical expressions for mean and variance of the cumulative damage distribution under both stationary narrow-band and stationary wide-band random process are provided. The mean value and variance of fatigue life distribution are then evaluated to determine the optimal replacement intervals under fatigue failure. A practical example is presented to demonstrate the application of the present method.

scholarly journals Reliability Analysis of a Mono-Tower Platform

1990 ◽  
Vol 112 (3) ◽  
pp. 237-243 ◽  
Author(s):  
P. H. Kirkegaard ◽  
I. Enevoldsen ◽  
J. D. So̸rensen ◽  
R. Brincker
Keyword(s):  
Fatigue Strength ◽  
Reliability Analysis ◽  
Failure Mode ◽  
Fatigue Failure ◽  
Cross Sections ◽  
Failure Modes ◽  
Damping Ratio ◽  
Limit State ◽  
Cumulative Fatigue Damage ◽  
Fatigue Limit State

In this paper, a reliability analysis of a Mono-tower platform is presented. The failure modes considered are yielding in the tube cross sections and fatigue failure in the butt welds. The fatigue failure mode is investigated with a fatigue model, where the fatigue strength is expressed through SN relations. In determining the cumulative fatigue damage, Palmgren-Miner’s rule is applied. Element reliability, as well as systems reliability, is estimated using first-order reliability methods (FORM). The sensitivity of the systems reliability to various parameters is investigated. It is shown that the fatigue limit state is a significant failure mode for the Mono-tower platform. Further, it is shown for the fatigue failure mode that the largest contributions to the overall uncertainty are due to the damping ratio, the inertia coefficient, the stress concentration factor, the model uncertainties, and the parameters describing the fatigue strength.

Fatigue Reliability Analysis of a Suspension Bridge Using Long-Term Monitoring Data

2006 ◽  
Vol 321-323 ◽  
pp. 223-229 ◽  
Author(s):  
Yi Qing Ni ◽  
X.W. Ye ◽  
Jan Ming Ko
Keyword(s):  
Fatigue Life ◽  
Reliability Analysis ◽  
Measurement Data ◽  
Life Assessment ◽  
Monitoring Data ◽  
Fatigue Reliability ◽  
Long Term Monitoring ◽  
Tsing Ma Bridge ◽  
Term Monitoring

A method for probabilistic fatigue life assessment of steel bridges by using long-term monitoring data is proposed and applied for fatigue reliability analysis of the suspension Tsing Ma Bridge. In this method, the daily number of cycles for each stress range is obtained from the measured stress history and its probability distribution is estimated based on statistical analysis of long-term measurement data. The statistics obtained for all concerned stress ranges is combined with the S−N relationships stipulated in specifications to conduct a probabilistic assessment of fatigue life with the use of the Palmgren-Miner rule, from which the mean value and standard deviation of the fatigue life as well as the failure probability and reliability index versus fatigue life are obtained. The proposed method is illustrated by using 80-day strain measurement data from the suspension Tsing Ma Bridge which is instrumented with a long-term structural health monitoring system.

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