Calculation Error Analysis on the Strain Fatigue Life Predication Formula of Manson-Coffinn and Damage Stain Model

Mechanical components are subjected heavy alternate load in industries, such as engine crankshaft, wheel axle, etc. The fatigue failure happens after a long work loading, which affects the production cost, safe and time. So the fatigue life predication is fundamental for the mechanical components design. Especially, it is very important for heavy, high-speed machinery. In this paper, both main fatigue life predication formulas are introduced briefly, including Manson-Coffinn formula and Damage strain model. Then, shortages of above life predication formulas are pointed out, and coefficients are explained in detail. Further calculation error analysis is conducted on the basis of experiments on 16 materials. Results show that above life predication formulas lack calculation accuracy. Finally, it is pointed out that coefficients of fatigue life predication formulas are dependent of material performance. So it is unreliable that coefficients are constants for Manson-Coffin and Damage strain model.

Download Full-text

Fatigue Life Characteristics of Segmental Lining Structure for the Shallow Buried Metro Tunnel under the Dynamic Load of a High-Speed Railway

Mathematical Problems in Engineering ◽

10.1155/2018/8736786 ◽

2018 ◽

Vol 2018 ◽

pp. 1-13 ◽

Cited By ~ 2

Author(s):

Wangping Qian ◽

Taiyue Qi ◽

Qing Zhao ◽

Bingrong Pu ◽

Jin Zhang ◽

...

Keyword(s):

Fatigue Life ◽

Fatigue Failure ◽

Dynamic Load ◽

High Speed ◽

Dynamic Loads ◽

High Speed Railway ◽

Segmental Lining ◽

Lining Structure ◽

Metro Tunnel

Shallow buried shield metro tunnels constructed underneath subgrade project of high-speed railways are becoming increasingly common in China, but the lower metro tunnel bears the fatigue effect of dynamic load induced by the upper high-speed railway, so the long-term durability of segmental lining is a nonnegligible problem. The segmental lining structure of metro tunnel is in a state of static-dynamic loads for a long time, especially when a high-speed railway passes above the metro line, and the long-term durability of segmental lining needs further research. Based on theoretical analysis, the effect of different forms of loads on the fatigue life was analyzed, the change law of the static-dynamic loads on segmental lining was summarized, and the method was put forward to evaluate the fatigue life characteristics of segmental lining. The research results reveal that the additional dynamic load is the fundamental reason for the fatigue failure of the structure, and the existence of static load can cause and accelerate the occurrence of structural fatigue failure simultaneously. The results indicate that the fatigue life decreases gradually with the increase of static-dynamic load. Based on coupling analysis of static-dynamic loads of segmental lining, the fatigue life increases first and then decreases with the increase of buried depth of metro tunnel, and it remains unchanged when the depth exceeds a certain value. According to the actual metro tunnel engineering, by using ABAQUS software, a three-dimensional numerical simulation was carried out to analyze the characteristics of the fatigue life and evolution rules of segmental lining. Based on the modified fatigue life formula and metro service life, the optimization design of the buried depth was carried out to determine the most reasonable range of the buried depth. This study provides a valuable reference for safe operation and long-term durability of metro tunnels under high-speed railways.

Download Full-text

Fatigue Reliability Based Optimal Replacement Decision of Mechanical Components

Computer Technology and Applications ◽

10.1115/pvp2004-2762 ◽

2004 ◽

Author(s):

Jun Tang ◽

Young Ho Park

Keyword(s):

Decision Making ◽

Fatigue Life ◽

Random Process ◽

Fatigue Failure ◽

Cumulative Damage ◽

Analytical Models ◽

Damage Distribution ◽

Optimal Replacement ◽

The Mean ◽

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 based on fatigue failure of mechanical components. This new approach is based on the cumulative damage distribution function for evaluating mean fatigue life. By using the approach, the analytical expressions for the mean and the 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 the fatigue life distribution are thus evaluated to determine the optimal replacement intervals under fatigue failure. An algorithm of evaluating the mean and standard deviation of fatigue life is also presented. Therefore, the reliability of a component under random cyclic loading for a specified duration is quantified accordingly. Even though the new method introduces a great deal of complexity in the analytical models, this method can efficiently determine replacement intervals for component whose operating costs increases with use and replacement intervals for component subject to failure induced by the random process. An example is presented to demonstrate the application of the present method.

Download Full-text

Failure analysis and fatigue life prediction of high-speed rail clips based on DIC technique

Advances in Mechanical Engineering ◽

10.1177/16878140211066225 ◽

2021 ◽

Vol 13 (12) ◽

pp. 168781402110662

Author(s):

Yan Liu ◽

Xiujie Jiang ◽

Qiutong Li ◽

Huan Liu

Keyword(s):

Fatigue Life ◽

Service Life ◽

Fatigue Failure ◽

High Speed ◽

Experimental Tests ◽

Image Correlation ◽

Fe Model ◽

Rail Transportation ◽

High Speed Rail ◽

Dic Technique

With the development of rail transportation, the fatigue failure of rail clips has become an issue, which affects the operational safety of trains. In this study, reasons for the fatigue failure of rail clips were investigated to improve their service life. A digital image correlation (DIC) technique was conducted to obtain strain fields, vibration modes, and natural frequencies of a rail clip. The strain and displacement of a rail clip under dynamic cyclic loading were also obtained. A fastener system refinement model was developed to analyze the static, dynamic, and modal responses of the clip. The experimental tests and modal simulation results were mutually verified. The fatigue life was analyzed based on the verified FE model. The results revealed that the maximum strain and minimum fatigue life occur at the heel of the clip, in good agreement with the actual fracture position. As the amplitude and frequency of dynamic cyclic load increased, the fatigue life of the clip decreased sharply. Moreover, the normal wheel–rail force accompanied by high-frequency rail corrugations accelerated crack initiation and reduced the fatigue life. The findings of this study provide guidance for improving the service life of rail clips.

Download Full-text

Optimum Replacement Interval for Mechanical Components Based on Fatigue Reliability

Journal of Pressure Vessel Technology ◽

10.1115/1.2767359 ◽

2006 ◽

Vol 129 (4) ◽

pp. 683-688 ◽

Cited By ~ 1

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

Download Full-text

An Efficient Methodology for Fatigue Reliability Analysis for Mechanical Components

Journal of Pressure Vessel Technology ◽

10.1115/1.2217960 ◽

2005 ◽

Vol 128 (3) ◽

pp. 293-297 ◽

Cited By ~ 2

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.

Download Full-text

Application of a Reliability Method to Maintenance Strategy for Mechanical Components

Volume 2: Computer Applications/Technology and Bolted Joints ◽

10.1115/pvp2008-61788 ◽

2008 ◽

Author(s):

Young Ho Park ◽

Iyad Hijazi ◽

Jun Tang

Keyword(s):

Decision Making ◽

Fatigue Life ◽

Fatigue Failure ◽

Wide Band ◽

Mean Value ◽

Cumulative Damage ◽

Damage Distribution ◽

Reliability Method ◽

The Mean ◽

Mechanical Components

This paper presents 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 based on fatigue failure of mechanical components. This new approach is based on the cumulative damage distribution function for evaluating mean fatigue life. By using the approach, the analytical expressions for the mean and the 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 the fatigue life distribution are thus evaluated to determine the optimal replacement intervals under fatigue failure. To evaluate probability function and the expected length of a failure cycle, approximated function forms were used.

Download Full-text

Load Spectrum Compiling and Fatigue Life Estimation of the Automobile Wheel Hub

Recent Patents on Mechanical Engineering ◽

10.2174/2212797613999201231200939 ◽

2020 ◽

Vol 13 ◽

Author(s):

Xintian Liu ◽

Yang Qu ◽

Xiaobing Yang ◽

Yongfeng Shen

Keyword(s):

Fatigue Life ◽

High Speed ◽

Two Dimensional ◽

Load Spectrum ◽

One Dimensional ◽

Life Estimation ◽

Load Spectra ◽

Fatigue Life Estimation ◽

Program Load Spectrum ◽

Program Load

Background:: In the process of high-speed driving, the wheel hub is constantly subjected to the impact load from the ground. Therefore, it is important to estimate the fatigue life of the hub in the design and production process. Objective:: This paper introduces a method to study the fatigue life of car hub based on the road load collected from test site. Methods:: Based on interval analysis, the distribution characteristics of load spectrum are analyzed. The fatigue life estimation of one - dimensional and two - dimensional load spectra is compared by compiling load spectra. Results:: According to the S-N curve cluster and the one-dimensional program load spectrum, the estimated range fatigue life of the hub is 397,100 km to 529,700 km. For unsymmetrical cyclic loading, each level means and amplitude of load were obtained through the Goodman fatigue empirical formula, and then according to S-N curve clusters in the upper and lower curves and two-dimensional program load spectrum, estimates the fatigue life of wheel hub of the interval is 329900 km to 435200 km, than one-dimensional load spectrum fatigue life was reduced by 16.9% - 17.8%. Conclusion:: This paper lays a foundation for the prediction of fatigue life and the bench test of fatigue durability of auto parts subjected to complex and variable random loads. At the same time, the research method can also be used to estimate the fatigue life of other bearing parts or high-speed moving parts and assemblies.

Download Full-text

Durability Analysis of the Reduction Gear for High Speed Train Considering Driving Histories

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.586.269 ◽

2012 ◽

Vol 586 ◽

pp. 269-273

Author(s):

Chul Su Kim ◽

Gil Hyun Kang

Keyword(s):

Fatigue Life ◽

High Speed ◽

Element Model ◽

Rolling Stock ◽

Reduction Gear ◽

High Speed Train ◽

Analysis Software ◽

Tractive Effort ◽

Durability Analysis ◽

The Finite Element Model

To assure the safety of the power bogies for train, it is important to perform the durability analysis of reduction gear considering a variation of velocity and traction motor capability. In this study, two types of applied load histories were constructed from driving histories considering the tractive effort and the train running curves by using dynamic analysis software (MSC.ADAMS). Moreover, this study was performed by evaluating fatigue damage of the reduction gears for rolling stock using durability analysis software (MSC.FATIGUE). The finite element model for evaluating the carburizing effect on the gear surface was used for predicting the fatigue life of the gears. The results showed that the fatigue life of the reduction gear would decrease with an increasing numbers of stops at station.

Download Full-text