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Article
Publication date: 1 July 1967

A.G. Woods

THE design and operation of a vibration simulator is described, and measurements of the body resonances of a number of people over the frequency range 1 to 10 c.p.s. for…

Abstract

THE design and operation of a vibration simulator is described, and measurements of the body resonances of a number of people over the frequency range 1 to 10 c.p.s. for vertical and lateral vibrations are presented. Comfort ratings have been obtained for these vibrations at various levels of acceleration. The response of an aircraft to atmospheric turbulence has been simulated assuming that the aircraft fuselage will vibrate predominantly in one flexible mode. Comfort ratings have been obtained for lateral turbulence, and a comparison has been made between these results and those for sinusoidal vibrations. The effect of random, vertical and lateral vibrations separately on task performance has been measured, also the effect of length of exposure to vibration on task performance for random vertical vibrations at various magnitudes.

Details

Aircraft Engineering and Aerospace Technology, vol. 39 no. 7
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 29 March 2011

Jinxue Sui, Xia Zhang, Li Yang, Zhilin Zhu and Zhang Xin

Vibration measurement is needed in many industrial production processes, such as equipment monitoring, fault diagnosis, and noise analysis and eliminating and so on. The…

Abstract

Purpose

Vibration measurement is needed in many industrial production processes, such as equipment monitoring, fault diagnosis, and noise analysis and eliminating and so on. The purpose of this paper is to propose a simple vibration testing system which includes the laser, the string, position sensitive detector (PSD) and the corresponding signal processing circuit.

Design/methodology/approach

PSD is an optical semiconductor sensor that can fast locate the luminous spot position precisely, which means that it can output different electric current according to the luminous spot at different position of its surface. Moreover, the experiment on PSD sensor using different vibration source and frequency had been carried out. Finally, the vibration waveform of the luminous spot on PSD photosurface was obtained.

Findings

According to the experimental results, each kind of vibration parameter with different vibration source, such as vibration frequency and amplitude can be calculated.

Originality/value

The experimental results agreed with the actual parameter, which showed PSD not only had its own good qualities in the position measurement, but also had the unique superiority in the vibration measurement.

Details

Sensor Review, vol. 31 no. 2
Type: Research Article
ISSN: 0260-2288

Keywords

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Article
Publication date: 18 February 2020

Mohammad Gharaibeh

This paper aims to investigate the fatigue life performance of SAC305 ball grid array solders under combined temperature and harmonic vibration loading conditions.

Abstract

Purpose

This paper aims to investigate the fatigue life performance of SAC305 ball grid array solders under combined temperature and harmonic vibration loading conditions.

Design/methodology/approach

Fatigue tests were performed using a sine dwell with resonance tracking vibration and temperature loading experiment. Finite element stress analysis was also performed to help in understanding the observed failure trends.

Findings

Fatigue test results showed that the lead-free solders tend to fail quickly in higher temperatures and higher vibration loading test conditions. The failure analysis results revealed that in low temperatures, the solder cracks are initiated and propagated at the package side. However, in high temperatures, the cracks are observed at the board side of the interconnect. In all conditions, the cracks are propagated throughout the intermetallic compound layer.

Originality/value

In the published literature, there is a lack of data in the area of fatigue assessment of lead-free solders under combined temperature and vibration loadings. This paper provides useful insights into combined thermal/vibration fatigue, i.e. reliability behavior of lead-free solder joint types.

Details

Soldering & Surface Mount Technology, vol. 32 no. 3
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 4 May 2012

Guangbin Tan, Ping Yang, Tianbo Li, Tao Xi, Xiaoming Yuan and Jianming Yang

The purpose of this paper is to provide a systematic method to perform analysis and test for vibration‐thermal strain behavior of plastic ball grid array (PBGA) assembly…

Abstract

Purpose

The purpose of this paper is to provide a systematic method to perform analysis and test for vibration‐thermal strain behavior of plastic ball grid array (PBGA) assembly by considering thermal and vibration loading mode. Also to investigate the dynamic behavior of PBGA assembly by considering loading modes for design and reliability evaluation of PBGA packaging.

Design/methodology/approach

A PBGA assembly prototype with different structure and material parameters is designed and manufactured. Based on investigation of the structural and physical parameters of PBGA sample, the vibration‐thermal strain test is developed to measure the strain distribution at the surface of the BT (bismaleimide triazine) substrates and PCB (printed circuit board) surface under vibration‐thermal cycling loading such as random vibration and the temperature is changed from 0°C to 100°C.

Findings

The test results show that the loading modes have different impact on PCB, EMC and substrate, respectively. In the meantime, it is shown that the characteristics of the compound mode is not the linear accumulative result by single vibration mode and single thermal loading mode as forecasted. The nonlinear mechanism for these modes application is the future work for progress.

Research limitations/implications

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

Practical implications

It implies a potential design characteristic for future application of PBGA assembly. It also builds a basis for future work for design and reliability evaluation of BGA package.

Originality/value

This paper fulfils useful information about the thermal‐vibration coupling dynamic behavior of PBGA assembly with different structure characteristics, materials parameters.

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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…

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

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Article
Publication date: 1 February 1973

This is the final part of the article by Gerhard H. Junker of the European Research and Engineering Standard Pressed Steel Co, Unbrako. Previous parts have covered…

Abstract

This is the final part of the article by Gerhard H. Junker of the European Research and Engineering Standard Pressed Steel Co, Unbrako. Previous parts have covered mechanism of self loosening, design to prevent self‐loosening and test methods.

Details

Aircraft Engineering and Aerospace Technology, vol. 45 no. 2
Type: Research Article
ISSN: 0002-2667

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Article
Publication date: 22 November 2018

Mohammad Gharaibeh, Aaron J. Stewart, Quang T. Su and James M. Pitarresi

This paper aims to investigate and compare the reliability performance of land grid array (LGA) and ball grid array (BGA) solders, as well as the SAC105 and 63Sn37Pb…

Abstract

Purpose

This paper aims to investigate and compare the reliability performance of land grid array (LGA) and ball grid array (BGA) solders, as well as the SAC105 and 63Sn37Pb solder alloys, in vibration loading conditions.

Design/methodology/approach

Reliability tests were conducted using a sine dwell with resonance tracking vibration experiment. Finite element simulations were performed to help in understanding the observed failure trends.

Findings

Reliability results showed that the tin-lead solders out-perform lead-free solders in vibrations loading. Additionally, the LGA solder type could provide a better vibration reliability performance than BGA solders. Failure analysis results showed that in LGAs, the crack is initiated at the printed circuit board side and at the component side in BGAs. In both types, the crack is propagated throughout in the intermetallic compound layer.

Originality/value

In literature, there is a lack of published data in the comparison between LGA and BGA reliability performance in vibration loadings. This paper provides useful insights in the vibration reliability behavior of the two common solder joint types.

Details

Soldering & Surface Mount Technology, vol. 31 no. 2
Type: Research Article
ISSN: 0954-0911

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Article
Publication date: 1 April 1990

Clive Williams

Outlines some basic forms of dynamic loading which causevibrational problems in structures. Presents information on thepossibility of structural damage occurring from…

Abstract

Outlines some basic forms of dynamic loading which cause vibrational problems in structures. Presents information on the possibility of structural damage occurring from vibration. Discusses the human response in terms of its often being the limiting factor in terms of amplitude which can be tolerated within a structure. Details industrial vibrational problems, covering areas of traffic, piling, forced vibration and industrial plant.

Details

Structural Survey, vol. 8 no. 4
Type: Research Article
ISSN: 0263-080X

Keywords

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Article
Publication date: 8 May 2018

Baoling Cui, Xiaodi Li, Kun Rao, Xiaoqi Jia and Xiaolin Nie

Radial vibration of horizontal centrifugal pump has a close association with radial exciting forces. The purpose of this paper is to analyze the unsteady radial force in…

Abstract

Purpose

Radial vibration of horizontal centrifugal pump has a close association with radial exciting forces. The purpose of this paper is to analyze the unsteady radial force in multistage centrifugal pump with double volute in detail and investigate the relevance of static pressure, radial force and radial vibration.

Design/methodology/approach

The unsteady numerical simulation with realizable k-ε turbulence model was carried out for a multistage centrifugal pump with double volute using computational fluid dynamics codes Fluent. The performance tests were conducted by use of a closed loop system and performance curves from numerical simulation agree with that of experiment. Vibration tests were carried out by vibration probes instrumented on the bearing cover of pump near no-driven end. Fast Fourier transform was used to obtain the frequency components of radial forces on the impellers from numerical simulation, which are compared with ones of radial vibration from experiment in Y and Z direction. And the static pressure distributions in the impeller were analyzed under different flow rates.

Findings

The symmetrical double volute can effectively balance radial forces. The maximum radial force and vibration velocity appear at 0.6 Q among the three flow rates 0.6 Q, Q and 1.2 Q. The frequencies corresponding to relatively large amplitude of vibration velocities and radial forces on the impellers in Y direction are blade passing frequency of the impellers. Blade passing frequency of first-stage impeller and shaft frequency are predominating in Z direction. It indicates that the radial vibration of centrifugal pump is closely related to the unsteady radial force.

Originality/value

The unsteady radial forces of the impeller in multistage centrifugal pump with double volute were comprehensively analyzed. The radial forces should be considered to balance during the design of multistage centrifugal pump.

Details

Engineering Computations, vol. 35 no. 3
Type: Research Article
ISSN: 0264-4401

Keywords

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Article
Publication date: 1 May 2020

Yanfeng Han, Lei Yin, Guo Xiang, Guangwu Zhou, Haizhou Chen and Xiaolin Zheng

The tribological behavior, i.e. friction coefficient and wear rate, and vibration characteristics of the water-lubricated bearing was investigated. The water-lubricated…

Abstract

Purpose

The tribological behavior, i.e. friction coefficient and wear rate, and vibration characteristics of the water-lubricated bearing was investigated. The water-lubricated bearing is made of three different materials, i.e. polyether-ether-ketone (PEEK), polyimide (PI) and nitrile-butadiene rubber (NBR).

Design/methodology/approach

The tribological behavior was investigated experimentally on a specially designed test rig. Three vibration sensors were used to record the vibration of the bearing.

Findings

The results indicated that the variation of friction coefficient with rotation speed agrees well with the trend of Stribeck curve. The tested friction coefficient of rubber bearing is higher than that of the other two bearings whether it is in the state of mixed-lubrication or hydrodynamic lubrication, and which causing a larger wear rate in rubber bearing. The PEEK bearing exhibits the best tribological properties due to it has smaller friction coefficient and wear rate. However, it can be found that the rubber bearing gives the minimum vibration acceleration, which means that the rubber bearing has the most potential to improve the stability of water-lubricated bearing rotor system.

Originality/value

In this study, a group of experiment studies conducted on a specially designed test rig. The comprehensive performance, including friction coefficient, vibration acceleration and wear rate, of water-lubricated bearing with three different materials, i.e. PEEK, PI and NBR, was compared systematically. The experiment research may offer a reference for the selection of material in water-lubricated bearing in specific operating conditions.

Peer review

The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-10-2019-0447/

Details

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

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