Accelerated Vibration Reliability Testing of Electronic Assemblies Using Sine Dwell With Resonance Tracking

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Quang T. Su ◽  
Mohammad A. Gharaibeh ◽  
Aaron J. Stewart ◽  
James M. Pitarresi ◽  
Martin K. Anselm
Keyword(s):  
Resonant Frequency ◽  
Measurement Techniques ◽  
Excitation Frequency ◽  
Building Blocks ◽  
Test Method ◽  
Circuit Board ◽  
Vibration Measurement ◽  
Fe Model ◽  
Reliability Testing ◽  
Sinusoidal Vibration

In this work, a sinusoidal vibration test method with resonance tracking is employed for reliability testing of circuit assemblies. The system continuously monitors for changes in the resonant frequency of the circuit board and adjusts the excitation frequency to match the resonant frequency. The test setup includes an electrodynamic shaker with a real-time vibration control, resistance monitoring for identifying electrical failures of interconnects, and vibration logging for monitoring changes in the dynamic response of the assembly over time. Reliability tests were performed using the resonance tracking sinusoidal test method for assemblies, each consisting of a centrally mounted ball grid array (BGA) device assembled with 63Sn37Pb and SAC105 solder alloys. These tests show that the resonance tracking method gives more consistent failure times. Failure analysis for the tested devices shows the primary failure mode is “input” trace crack first, followed by fatigue through the solder for complete failure. A finite element (FE) model, correlated with experimental modal analysis, is shown to accurately estimate the circuit board deflection estimated from the harmonic vibration data. This provides a means of estimating the stresses in the electronic interconnections while accounting for the variability between test parts. These fine-tuned vibration measurement techniques and related FE models provide the building blocks for high cycle solder fatigue plots (i.e., S–N curves).

Study on Mistuning Identification of Vehicle Turbocharger Turbine BLISK

2014 ◽  
Author(s):  
Hiroaki Hattori
Keyword(s):  
Excitation Frequency ◽  
Vibration Measurement ◽  
Experimental Result ◽  
Fe Model ◽  
Directionally Solidified ◽  
Blade Vibration ◽  
Operating Range ◽  
Measurement Result ◽  
Turbine Blisk ◽  
Analytical Result

Blade vibration is one of the most critical items to be solved in turbocharger design. Turbocharger has much broader operating range than other turbo machinery and some unavoidable resonance may remain in operating range. In such a critical situation, predicting resonant vibration level is desirable for evaluating criticality. Additionally, knowing what amount of margin should be taken for the predicted nominal vibratory stress (known as “Magnification Factor”) is also important for the structural design. Blade to blade vibration response have significant scatter in real rotor. This kind of phenomena is called as “mistuned bladed disk effect” and discussed by many researchers in aero-engine field. Some research studies have appeared also in the automotive turbocharger field but its feature is not well understood especially on the item of mistuning identification and the cause of mistuning. Considering above situation, studies on mistuned vibration were performed for turbine BLISK of automotive turbocharger. Three type of mistuning (frequency mistuning, geometric mistuning, and mistuning of macroscopic property of directionally solidified material) were assumed and these effect on above items (mistuning identification and the cause of mistuning) were investigated. This paper consists of three parts. At first, frequency mistune model and geometry mistune models were prepared. To build a frequency mistuning model, FMMID proposed by Feiner and Griffin [6] is applied. After the basic function test by virtual BLISK model with known mistuning, FMMID was applied to the actual BLISK. Natural frequency mistuning of each blade was identified by FMMID based on the modal measurement result. Obtained frequency mistuning is reflected to the (geometry tuned) FE model by changing the Young’s modulus of each blade in corresponding rate. The 3D measurement was also performed to the same BLISK and dimensional information from this measurement was reflected to the geometrically mistuned (material property tuned) FE model. In the next step, vibration analysis (eigenvalue and frequency response) was performed and these results were compared to the measurement result. Vibration measurement in operating condition was performed at the resonant point of mode3 and nozzle count excitation frequency by utilizing the NSMS (Non-intrusive stress measurement system). Analytical result of the frequency mistuning model shows a good agreement with the experimental, while the analytical results of the geometrically mistuned model did not match to the experimental result. At the last part, cause of discrepancy between the analytical result of the geometry mistuning model and the measured result was investigated from the view point of the effect of the anisotropy of elastic constants on the vibration characteristics of the DS (Directionally Solidified) blades.

scholarly journals Analysis of a Cantilevered Piezoelectric Energy Harvester in Different Orientations for Rotational Motion

Sensors ◽  
2020 ◽  
Vol 20 (4) ◽  
pp. 1206 ◽  
Author(s):  
Wei-Jiun Su ◽  
Jia-Han Lin ◽  
Wei-Chang Li
Keyword(s):  
Theoretical Model ◽  
Resonant Frequency ◽  
Rotational Motion ◽  
Axial Load ◽  
Energy Harvester ◽  
Excitation Frequency ◽  
Experimental Studies ◽  
Piezoelectric Energy ◽  
Piezoelectric Cantilever ◽  
Tip Mass

This paper investigates a piezoelectric energy harvester that consists of a piezoelectric cantilever and a tip mass for horizontal rotational motion. Rotational motion results in centrifugal force, which causes the axial load on the beam and alters the resonant frequency of the system. The piezoelectric energy harvester is installed on a rotational hub in three orientations—inward, outward, and tilted configurations—to examine their influence on the performance of the harvester. The theoretical model of the piezoelectric energy harvester is developed to explain the dynamics of the system and experiments are conducted to validate the model. Theoretical and experimental studies are presented with various tilt angles and distances between the harvester and the rotating center. The results show that the installation distance and the tilt angle can be used to adjust the resonant frequency of the system to match the excitation frequency.

scholarly journals Adaptive Electromagnetic Energy Harvester for Mobile Devices

2020 ◽  
Author(s):  
Haziq Kamal ◽  
Peyman Moghadam
Keyword(s):  
Resonant Frequency ◽  
Mobile Devices ◽  
Energy Harvester ◽  
Excitation Frequency ◽  
Electromagnetic Energy ◽  
Major Drawback ◽  
Energy Harvesters ◽  
Limited Effectiveness ◽  
Energy Harvesting Devices ◽  
Ambient Excitation

<div>Advances in design and development of light-weight and low power wearable and mobile devices open up the possibility of lifetime extension of these devices from ambient sources through energy harvesting devices as opposed to periodically recharge the batteries. The most commonly available ambient energy source for mobile devices is Kinetic energy harvesters (KEH). The major drawback of the energy harvesters is limited effectiveness of harvesting mechanism near a fixed resonant frequency. It is difficult to harvest a reliable amount of energy from every forms of device motions with different excitation frequencies. To overcome this drawback, in this paper we propose an adaptive electromagnetic energy harvester which utilises spring characteristics to adapt its resonant frequency to match the ambient excitation frequency. This paper presents a prototype design and analysis of an adaptive electromagnetic energy harvester both in simulation and real. The harvester has tested using a specially designed experimental setup and compared with numerical simulations. The proposed solution generates 3.5 times higher maximum power over the default power output and 2.4 times higher maximum frequency compared to a fixed resonant frequency electromagnetic energy harvester.</div>

Experimental Research on Vibration Characteristics of Laminated Composite Cantilever Beam

2021 ◽  
Author(s):  
Rui Yang ◽  
Xiaobin Li ◽  
Hongxi Li
Keyword(s):  
Cantilever Beam ◽  
Optical Measurement ◽  
Laminated Composite ◽  
Experimental Methods ◽  
Test Methods ◽  
Vibration Characteristics ◽  
Test Method ◽  
Vibration Measurement ◽  
Vibration Test ◽  
Test Results

Abstract In this paper, the vibration characteristics of laminated composite cantilever beam is taken as the research object. Firstly, a vibration formula specific for laminated composite cantilever beam is derived, from which the low order natural frequency of laminated composite cantilever beam is calculated; Secondly, two experimental methods, electrical and optical measurement, are used to study the vibration characteristics of laminated composite cantilever beam, and the influence of different test methods, sensor types, number of measuring points and excitation methods on the test results are analyzed. Through the combination of theory and experiment, a test method that can be applied to the vibration test of composite material laminated structure cantilever beam is obtained. Based on the laser vibration measurement method in the optical method, the results show that the deviation between the experimental data and the theoretical solution is the smallest when the distance between the probe and the specimen is 0.5m and the sampling time is 5s by using the optical fiber vibrometer. The research content of this article can provide a reasonable reference for related vibration test research.

I/O Printed Circuit Board Assemblies; Recent Learning in Mechanical Stress Analysis, Verification Testing, and Post-test Analysis Techniques and Results

2015 ◽  
Vol 2015 (1) ◽  
pp. 000169-000178
Author(s):  
John Torok ◽  
Shawn Canfield ◽  
Suraush Khambati ◽  
Robert Mullady ◽  
Budy Notohardjono ◽  
...  
Keyword(s):  
Printed Circuit Board ◽  
Measurement Techniques ◽  
Form Factors ◽  
Mechanical Analysis ◽  
Circuit Board ◽  
Mechanical Shock ◽  
Test Analysis ◽  
Printed Circuit ◽  
Analysis Techniques ◽  
Post Test

Recent high-end server designs have included new Input / Output (I/O) printed circuit board (PCB) assemblies consisting of a variety of form factors, electronic design layouts, and packaging assembly characteristics. To insure the required functional and reliability aspects are established and maintained, new mechanical analysis and verification testing techniques have been recently devised. A description of the design application set, the analysis tools and techniques applied, and the verification testing completed, including the associated measurement techniques as well as post-testing analysis methods and results are presented. Also included are the recent PCB raw card characterization efforts whose results have been applied as material property inputs to the analysis to improve analytical-to-empirical correlation. Included within the application set are both the use of custom designed cards as well as industry standard, original equipment manufacturer (OEM) cards that are packaged within custom enclosures. Given packaged and unpackaged (i.e., as installed in a higher-level rack system assembly) fragility testing requirements, new analysis techniques exploiting the capabilities of LS-DYNA have been used to provide a predictive means to support both initial as well as iterative design levels. In addition, these analysis results are also used to identify locations for measurement sensor placement employed during mechanical verification testing. Thermal shock and mechanical shock and vibration verification testing details and results are provided describing the conditions applied to simulate assembly shipping conditions, both as packaged as well as in situ to the higher-level of assembly. Included with this is a discussion with respect to post-test analysis techniques and results, including the use of both microscopic cross-section analysis as well as dye-pry assessments. Concluding, continued and future activities are described as “best practices” for the application of this methodology as part of the end-to-end development process.

Round-Robin of High-Frequency Test Methods by IPC-D24C Task Group

2016 ◽  
Vol 13 (3) ◽  
pp. 77-94
Author(s):  
Glenn Oliver ◽  
Jonathan Weldon ◽  
Chudy Nwachukwu ◽  
John Andresakis ◽  
John Coonrod ◽  
...  
Keyword(s):  
Dielectric Properties ◽  
High Frequency ◽  
High Speed ◽  
Test Methods ◽  
Round Robin ◽  
Standard Test ◽  
Test Method ◽  
Task Group ◽  
Circuit Board ◽  
Industry Standard

Currently, there is no industry standard test method for measuring dielectric properties of circuit board materials at frequencies greater than ~10 GHz. Various material vendors and test laboratories apply different approaches to determine these properties. It is common for these different approaches to yield varying values of key properties such as permittivity and loss tangent. The D-24C Task Group of IPC has developed this round-robin program to assess these various methods from the “bottom up” to determine if standardized methods can be agreed upon to provide the industry with more accurate and valid characteristics of dielectrics used in high-frequency and high-speed applications.

A NEW DESIGN FOR A MULTIFUNCTIONAL CONTACT-PIN TYPE PULSE TRANSDUCER

2001 ◽  
Vol 13 (06) ◽  
pp. 262-266 ◽  
Author(s):  
ALBERT CHIN-YUH LIN ◽  
HSING-CHENG CHANG ◽  
CHIA-ZHENG DAI ◽  
KAE-CHYUN YU ◽  
TSUNG-HUNG CHEN
Keyword(s):  
Circuit Board ◽  
Vibration Measurement ◽  
Driving Mechanism ◽  
Pulse Waveform ◽  
Thin Membrane ◽  
Physical Measurements ◽  
Pulse Transducer ◽  
Special Apparatus ◽  
Improve Reliability

In this paper, a new contact-pin type pulse transducer is designed to improve reliability of the pulse-waveform acquisition. The transducer contains two pressure sensor dies with two contact pins on the top, a wire-bonded circuit board, and power driving mechanism. The designed contact-pin is firmly supported by a thin membrane on the package of the transducer. It can minimize the friction for vibration measurement and can easy adjust misalignment for long-term physical measurements that can be used to accurately extract more pulse information by measuring pulse waveforms from the wrist artery. Some special apparatus designed as fixtures have been setup for the transducer fabrication and applications. Experimental results show that the designed contact-pin transducer is robust and feasible for further applications.

A Gaussian Process-Based Crack Pattern Modeling Approach for Battery Anode Materials Design

2020 ◽  
Vol 18 (1) ◽  
Author(s):  
Zhuoyuan Zheng ◽  
Bo Chen ◽  
Yanwen Xu ◽  
Nathan Fritz ◽  
Yashraj Gurumukhi ◽  
...  
Keyword(s):  
Gaussian Process ◽  
Surrogate Model ◽  
Lithium Ion ◽  
Building Blocks ◽  
Electrochemical Process ◽  
Fe Model ◽  
Model Framework ◽  
Major Drawback ◽  
Cracking Behavior ◽  
Si Anode

Abstract Silicon-based anodes are one of the promising candidates for the next generation high-power/energy density lithium ion batteries (LIBs). However, a major drawback limiting the practical application of the Si anode is that Si experiences a significant volume change during lithiation/delithiation, which induces high stresses causing degradation and pulverization of the anode. This study focuses on crack initiation within a Si anode during the delithiation process. A multi-physics-based finite element (FE) model is built to simulate the electrochemical process and crack generation during delithiation. On top of that, a Gaussian process (GP)-based surrogate model is developed to assist the exploration of the crack patterns within the anode design space. It is found that the thickness of the Si coating layer, TSi, the yield strength of the Si material, σFc, the cohesive strength between Si and the substrate, σFs, and the curvature of the substrate, ρ, have large impacts on the cracking behavior of Si. This coupled FE simulation-GP surrogate model framework is also applicable to other types of LIB electrodes and provides fundamental insights as building blocks to investigate more complex internal geometries.

Study of Oil Starvation in Journal Bearing Using Acoustic Emission and Vibration Measurement Techniques

2020 ◽  
Vol 142 (12) ◽  
Author(s):  
Surojit Poddar ◽  
N. Tandon
Keyword(s):  
Acoustic Emission ◽  
Journal Bearing ◽  
Measurement Techniques ◽  
Peak Frequency ◽  
Vibration Measurement ◽  
Frequency Range ◽  
Frequency Shifts ◽  
Deformation And Fracture ◽  
Asperity Contacts ◽  
Ae Signals

Abstract This present article evaluates the state of starvation in a journal bearing using acoustic emission (AE) and vibration measurement techniques. A journal bearing requires a constant supply of oil in an adequate amount to develop a hydrodynamic film, thick enough to separate the surfaces and avoid asperity contacts. On a microscopic level, the surface interaction under starved lubrication results in deformation and fracture of asperities. This causes a proportionate increase in AE and vibration. The AE activities resulting from asperities interaction have significant energy in the frequency range of 100–400 kHz with peak frequencies in the range of 224–283 kHz. Further, the peak frequency shifts from the higher to lower side as the asperity interaction transits from the elastic to plastic contact. This information derived from the spectral analysis of AE signals can be used to develop condition monitoring parameters to proactively control the lubrication and prevent bearing failure.

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