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Article
Publication date: 2 September 2019

Reza Manouchehry Nya, Shahrum Abdullah and Salvinder Singh Karam Singh

The purpose of this paper is to analyse fatigue-life prediction based on a reliability assessment for coil springs of vehicle suspension systems using different road excitations…

Abstract

Purpose

The purpose of this paper is to analyse fatigue-life prediction based on a reliability assessment for coil springs of vehicle suspension systems using different road excitations under random loading.

Design/methodology/approach

In this study, a reliability assessment was conducted to predict the fatigue life of an automobile coil spring during different road data surfaces. Campus, urban and highway road surfaces were considered to capture fatigue load strain histories using a data acquisition system. Random loadings are applied on top of a coil spring where coil is fixed from down. Fatigue reliability was established as a system of correlated events during the service life to predict the probability of fatigue life using Coffin–Manson, Morrow and Smith–Watson–Topper (SWT) models.

Findings

Fatigue-life prediction based on a reliability assessment revealed that the Morrow model can predict a safe region of a life data point for the three road surfaces. Highway road data indicated the highest rate of reliability at 0.8 for approximately 1.69 × 105 cycles for the SWT model.

Originality/value

Reliability assessment of the fatigue life of vehicle coil springs is vital for safe operation. The reliability analysis of a coil spring under random loading excitations can be used for fatigue-life prediction.

Details

International Journal of Structural Integrity, vol. 10 no. 5
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 11 August 2023

Jianhui Liu, Ziyang Zhang, Longxiang Zhu, Jie Wang and Yingbao He

Due to the limitation of experimental conditions and budget, fatigue data of mechanical components are often scarce in practical engineering, which leads to low reliability of…

Abstract

Purpose

Due to the limitation of experimental conditions and budget, fatigue data of mechanical components are often scarce in practical engineering, which leads to low reliability of fatigue data and reduces the accuracy of fatigue life prediction. Therefore, this study aims to expand the available fatigue data and verify its reliability, enabling the achievement of life prediction analysis at different stress levels.

Design/methodology/approach

First, the principle of fatigue life probability percentiles consistency and the perturbation optimization technique is used to realize the equivalent conversion of small samples fatigue life test data at different stress levels. Meanwhile, checking failure model by fitting the goodness of fit test and proposing a Monte Carlo method based on the data distribution characteristics and a numerical simulation strategy of directional sampling is used to extend equivalent data. Furthermore, the relationship between effective stress and characteristic life is analyzed using a combination of the Weibull distribution and the Stromeyer equation. An iterative sequence is established to obtain predicted life.

Findings

The TC4–DT titanium alloy is selected to assess the accuracy and reliability of the proposed method and the results show that predicted life obtained with the proposed method is within the double dispersion band, indicating high accuracy.

Originality/value

The purpose of this study is to provide a reference for the expansion of small sample fatigue test data, verification of data reliability and prediction of fatigue life data. In addition, the proposed method provides a theoretical basis for engineering applications.

Details

International Journal of Structural Integrity, vol. 14 no. 5
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 8 March 2011

Thomas J. Spradlin, Ramana V. Grandhi and Kristina Langer

The purpose of this paper is to develop and implement a structural fatigue life estimation framework that includes laser‐peened (LP) residual stresses and then experimentally…

Abstract

Purpose

The purpose of this paper is to develop and implement a structural fatigue life estimation framework that includes laser‐peened (LP) residual stresses and then experimentally validates these fatigue life estimations.

Design/methodology/approach

A three‐dimensional finite element analysis of an Al 7075‐O three‐point bending coupon being LP was created and used to estimate the fatigue life when loaded. Fatigue tests were conducted to validate these estimations.

Findings

The framework developed for fatigue life estimation of LP‐processed coupons yielded estimates with goodness‐of‐fit between the log‐transformed experimental and analytical data of R2=0.97 for the baseline coupons and R2=0.94 for the LP‐processed coupons.

Research limitations/implications

Approximated εlife fatigue parameters were used to calculate the fatigue life resulting from the complex residual stress fields due to the simulated LP process.

Originality/value

A fatigue life estimation framework that considers LP residual stress fields has been developed for use on structural components.

Details

International Journal of Structural Integrity, vol. 2 no. 1
Type: Research Article
ISSN: 1757-9864

Keywords

Open Access
Article
Publication date: 29 May 2020

Li Cui

Bearings in electric machines often work in high speed, light load and vibration load conditions. The purpose of this paper is to find a new fatigue damage accumulation rating life

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Abstract

Purpose

Bearings in electric machines often work in high speed, light load and vibration load conditions. The purpose of this paper is to find a new fatigue damage accumulation rating life model of ball bearings, which is expected for calculating fatigue life of ball bearings more accurately under vibration load, especially in high speed and light load conditions.

Design/methodology/approach

A new fatigue damage accumulation rating life model of ball bearings considering time-varying vibration load is proposed. Vibration equations of rotor-bearing system are constructed and solved by Runge–Kutta method. The modified rating life and modified reference rating life model under vibration load is also proposed. Contrast of the three fatigue life models and the influence of dynamic balance level, rotating speed, preload of ball bearings on bearing’s fatigue life are analyzed.

Findings

To calculate fatigue rating life of ball bearings more accurately under vibration load, especially in high speed and light load conditions, the fatigue damage accumulation rating life model should be considered. The optimum preload has an obvious influence on fatigue rating life.

Originality/value

This paper used analytical method and model that is helpful for design of steel ball bearing in high speed, light load and vibration load conditions.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-05-2019-0180/

Details

Industrial Lubrication and Tribology, vol. 72 no. 10
Type: Research Article
ISSN: 0036-8792

Keywords

Article
Publication date: 11 January 2021

Haijie Wang, Xintian Liu, Que Wu, Xiaolan Wang and Yansong Wang

The purpose of this paper is to obtain a more accurate fatigue life of structures by introducing the surface roughness into fatigue life prediction model.

Abstract

Purpose

The purpose of this paper is to obtain a more accurate fatigue life of structures by introducing the surface roughness into fatigue life prediction model.

Design/methodology/approach

Based on the fatigue life prediction model with surface roughness correction, the shock absorber cylinder is taken as an example to verify the feasibility of the improved method. Based on the load of the shock absorber cylinder during driving, fatigue experiments are performed under longitudinal and lateral forces, respectively. Then, the fatigue life predicted by the modified model is compared with that predicted by the traditional model.

Findings

By comparing with the test results, considering the influence of mean stress, the Manson method is more accurate in life prediction. Then, the modified Manson-Coffin and Manson method with surface roughness is more accurate in life prediction under longitudinal force and lateral forces, respectively. This verifies the feasibility of the improved method with the surface roughness.

Originality/value

The research on the influence of surface roughness on fatigue life can lay the technical foundation for the life prediction of products and have great significance to the quality evaluation of products.

Details

Engineering Computations, vol. 38 no. 6
Type: Research Article
ISSN: 0264-4401

Keywords

Article
Publication date: 17 October 2023

Yaobing Wei, Yanan Li, Jianhui Liu, Gai Wang, Yanlei Guo and Xuemei Pan

In practical engineering, oil filters often work under asymmetric cyclic loading. In order to improve the prediction accuracy of fatigue life of the oil filters under asymmetric…

Abstract

Purpose

In practical engineering, oil filters often work under asymmetric cyclic loading. In order to improve the prediction accuracy of fatigue life of the oil filters under asymmetric cyclic loading, the effect of strain ratio and low cycle fatigue plastic deformation on fatigue life need to be considered. This paper aims to discuss the aforementioned objective.

Design/methodology/approach

First, strain-controlled fatigue tests with strain ratios of 0, 0.5 and −1 were carried out on the oil filter material 2A70-T6 aluminum alloy, and the test data were used to obtain strain fatigue life curves at three strain ratios. Then, based on the idea of the constant life curve method, the average value of the ratio of the strain amplitude corresponding to different strain ratios under the same partial life was defined as the strain ratio factor. Finally, the elastic-plastic factor was modified by the strain ratio factor, and a new fatigue life prediction model considering the effect of strain ratio was proposed.

Findings

The proposed model was validated, respectively, by fatigue test data of 2A70-T6 aluminum alloy, 2124-T851 aluminum alloy and oil filter and the results of the proposed model were compared with the Coffin–Manson equation, Morrow model and Smith–Watson–Topper (SWT) model, showing that the proposed model had higher applicability and accuracy.

Originality/value

In this work, a strain ratio factor is established based on the idea of the constant life curve method, and the strain ratio factor is used to modify the introduced elastic-plastic factor, and then a new fatigue life prediction model considering the influence of strain ratio and low cycle fatigue plastic deformation on material fatigue damage accumulation is proposed. The results show that the prediction results of the proposed model are in good agreement with the experimental data, and the proposed model has good fatigue life prediction ability considering the influence of strain ratio and lays a foundation for the fatigue life prediction of the oil filter.

Details

International Journal of Structural Integrity, vol. 14 no. 6
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 25 July 2019

Lennie Abdullah, Salvinder Singh Karam Singh, Abdul Hadi Azman, Shahrum Abdullah, Ahmad Kamal Ariffin Mohd Ihsan and Yat Sheng Kong

This study aims to determine the reliability assessment based on the predicted fatigue life of leaf spring under random strain loading.

Abstract

Purpose

This study aims to determine the reliability assessment based on the predicted fatigue life of leaf spring under random strain loading.

Design/methodology/approach

Random loading data were extracted from three various road conditions at 200 Hz using a strain gauge for a duration of 100 s. The fatigue life was predicted using strain-life approaches of Coffin–Manson, Morrow and Smith–Watson–Topper (SWT) models.

Findings

The leaf spring had the highest fatigue life of 1,544 cycle/block under highway data compared uphill (1,299 cycle/block) and downhill (1,008 cycle/block) data. Besides that, the statistical properties of kurtosis showed that uphill data were the highest at 3.81 resulted in the presence of high amplitude in the strain loading data. For fatigue life-based reliability assessment, the SWT model provided a narrower shape compared to the Coffin–Manson and Morrow models using the Gumbel distribution. The SWT model had the lowest mean cycle to failure of 1,250 cycle/block followed by Morrow model (1,317 cycle/block) and the Coffin–Manson model (1,429 cycle/block). The SWT model considers the mean stress effects by interpreting the strain energy density that will influence the reliability assessment.

Research limitations/implications

The reliability assessment based on fatigue life prediction is conducted using the Gumbel distribution to investigate the behaviour of fatigue random loading, where most previous studies had concentrated on a Weibull distribution on random data.

Originality/value

Thus, this study proposes that the Gumbel distribution is suitable for analysing the reliability of random loading data in assessing with the fatigue life prediction of a heavy vehicle leaf spring.

Details

International Journal of Structural Integrity, vol. 10 no. 5
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 4 November 2019

Shuangshuang Li, Xintian Liu, Xiaolan Wang and Yansong Wang

During the running of automobile, the stabilizer bar is frequently subjected to the impact of complex random loads, which is prone to fatigue failure and accident. In regard to…

Abstract

Purpose

During the running of automobile, the stabilizer bar is frequently subjected to the impact of complex random loads, which is prone to fatigue failure and accident. In regard to this, the purpose of this paper is to study and discuss fatigue life of automobile stabilizer bar.

Design/methodology/approach

Durability bench test shows that failure is located at the joint of sleeve and stabilizer bar body. Based on the collection and compilation of micro-strain load spectrum of the stabilizer bar, the strain-life model is studied considering the influence of average stress and maximum stress at failure area. Seven-grade strain-life curves of the stabilizer bar are established. According to the principle of linear damage accumulation, the relationship between fatigue life and damage is discussed, then the fatigue life of stabilizer bar is predicted. Fatigue life evaluation is carried out from three aspects: reliability analysis, static analysis and fatigue life simulation.

Findings

The results show that the reliability of the test sample is 99.9 percent when the confidence is 90 percent and the durability is 1,073 load spectrum cycles; the ratios of predicted and simulated life to design life are 2.77 and 2.30, respectively.

Originality/value

Based on the road load characteristics of automobile stabilizer bar, the method of fatigue life prediction and evaluation is discussed, which provides a basis for the design and development of automobile chassis components.

Details

International Journal of Structural Integrity, vol. 11 no. 2
Type: Research Article
ISSN: 1757-9864

Keywords

Article
Publication date: 29 April 2014

Ping Yang, Xiusheng Tang, Yu Liu, Shuting Wang and Jianming Yang

The purpose of this paper is to perform experimental tests on fatigue characteristics of chip scale package (CSP) assembly under vibration. Some suggestions for design to prolong…

Abstract

Purpose

The purpose of this paper is to perform experimental tests on fatigue characteristics of chip scale package (CSP) assembly under vibration. Some suggestions for design to prolong fatigue life of CSP assembly are provided.

Design/methodology/approach

The CSP assembly which contains different package structure modes and chip positions was manufactured. The fatigue characteristics of CSP assembly under vibration were tested. The fatigue load spectrum of CSP assembly was developed under different excitation. The fatigue life of chips can be estimated by using the high-cycle fatigue life formula based on different stress conditions. The signal–noise curve shows the relationship between fatigue life and key factors. The design strategy for improving the fatigue life of CSP assembly was discussed.

Findings

The CSP chip has longer fatigue life than the ball grid array chip under high cyclic strain. The closer to fixed point the CSP chip, the longer fatigue life chips will have. The chip at the edge of the printed circuit board (PCB) has longer fatigue life than the one in the middle of the PCB. The greater the excitation imposed on the assembly, the shorter the fatigue life of chip.

Research limitations/implications

It is very difficult to set up a numerical approach to illustrate the validity of the testing approach because of the complex loading modes and the complex structure of CSP assembly. The research on an accurate mathematical model of the CSP assembly prototype is a future work.

Practical implications

It builds a basis for high reliability design of high-density CSP assembly for engineering application. In addition, vibration fatigue life prediction method of chip-corner solder balls is deduced based on three-band technology and cumulative damage theory under random vibration so as to verify the accuracy of experimental data.

Originality/value

This paper fulfils useful information about the dynamic reliability of CSP assembly with different structural characteristics and material parameters.

Details

Microelectronics International, vol. 31 no. 2
Type: Research Article
ISSN: 1356-5362

Keywords

Article
Publication date: 1 October 1967

J.A.B. Lambert and A.J. Troughton

An examination of the advantages of fail safe design and present non‐destructive testing techniques, and the importance of facilitating inspection at the design stage. THE…

Abstract

An examination of the advantages of fail safe design and present non‐destructive testing techniques, and the importance of facilitating inspection at the design stage. THE introduction to this paper justifies in depth the case for fail safe philosophies in aircraft structural design. The advantages include improved safety, weight savings, the full availability of the potential fatigue life of each individual aircraft in the fleet, protection against accidental damage in service and manufacturing errors, together with a good resale value.

Details

Aircraft Engineering and Aerospace Technology, vol. 39 no. 10
Type: Research Article
ISSN: 0002-2667

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