Numerical simulation and fatigue life estimation of BGA packages under random vibration loading

2015 ◽  
Vol 55 (12) ◽  
pp. 2777-2785 ◽  
Author(s):  
Fang Liu ◽  
Ye Lu ◽  
Zhen Wang ◽  
Zhiming Zhang
Keyword(s):  
Numerical Simulation ◽  
Fatigue Life ◽  
Random Vibration ◽  
Life Estimation ◽  
Vibration Loading ◽  
Bga Packages ◽  
Fatigue Life Estimation

Application of Power Spectral Density Method to Fatigue Life Estimation of the Axle Structure

2014 ◽  
Vol 487 ◽  
pp. 272-275
Author(s):  
Rui Feng Guo ◽  
Peng Li Wang
Keyword(s):  
Fatigue Life ◽  
Spectral Density ◽  
Density Function ◽  
Power Spectral Density ◽  
Random Vibration ◽  
Spectral Density Function ◽  
Power Spectral Density Function ◽  
Life Estimation ◽  
Power Spectral ◽  
Fatigue Life Estimation

Based on the random vibration theory, fatigue strength theory and Miner cumulative damage theory, the formulas for estimation of fatigue life which can be coped with narrowband and broadband random vibration was derived by the peak distribution function. The power spectral density function of axle structure is deduced after the power spectral density of standard road and the vibration model of wheel had studying. Combined the power spectral density function with broadband random vibration fatigue life estimation formula, the fatigue life of axle structure was obtained. This method is simple and has a strong engineering practicality.

Thermo-Mechanical Fatigue Life Estimation of Organic BGA Packages Using Laser Moire Interferometry

2006 ◽  
Author(s):  
Krishna Tunga ◽  
Suresh K. Sitaraman
Keyword(s):  
Fatigue Life ◽  
Thermal Cycling ◽  
Deformation Behavior ◽  
Life Estimation ◽  
Mechanical Fatigue ◽  
Joint Reliability ◽  
Bga Packages ◽  
Fatigue Life Estimation ◽  
Bga Package ◽  
Accelerated Thermal Cycling

Accelerated Thermal Cycling (ATC) is traditionally used for assessing solder joint reliability. ATC typically takes as long as three to four months to complete. This paper proposes a new method to determine the fatigue life of solder joints using laser moire´ technique. The developed method takes about a week to complete and gives us the detailed deformation behavior of each solder ball in the package at various temperatures. The developed method has been demonstrated for a high I/O organic BGA package. To illustrate the efficacy of the method, the results have been validated using experimental thermal cycling data.

Improvement of Pipeline Fatigue Life Estimation

2016 ◽  
Author(s):  
Sanjay Tiku ◽  
Aaron Dinovitzer ◽  
Vlad Semiga ◽  
Mark Piazza ◽  
Tom Jones
Keyword(s):  
Numerical Simulation ◽  
Growth Rate ◽  
Fatigue Crack ◽  
Fatigue Life ◽  
Crack Growth Rate ◽  
Fatigue Crack Growth ◽  
Crack Growth ◽  
Fatigue Crack Growth Rate ◽  
Life Estimation ◽  
Fatigue Life Estimation

Fracture mechanics methodologies for calculating fatigue lives have been successfully applied by pipeline operators to estimate integrity reassessment intervals. Their application in the definition of pipeline system fatigue lives has been overly conservative in actual practice. The source and magnitude of the conservatism inherent in the calculated fatigue life estimates needs to be identified so operators have a better indicator of when reassessments should take place. The pipe life estimation is especially critical for Electric Resistance Weld (ERW) and Electric Flash Weld (EFW) pipeline systems with longitudinally oriented defects. Prior work on improving fatigue life was initiated through studies completed by Pipeline Research Council International, Inc. (PRCI) to evaluate the sources of differences between fatigue life estimates produced by industry fatigue analysis software and different metallurgists. Two significant sources of conservatism in the fatigue life estimation process were identified: the fatigue crack growth rate (da/dN) and the bulging correction factor applied to axial surface flaws. The experimental and numerical simulation techniques considering the impact of these factors on rate of fatigue crack growth of pipeline axially oriented defects are described in this paper. Finite element modeling was used to simulate pipe bulging in the presence of axial flaws. The effect of the pipe thickness, diameter and flaw geometry was compared with treatments included in existing defect assessment standards. The results illustrate that for longer and deeper flaws existing treatments over represent the local bending due to pipe wall bulging. This results in unnecessarily conservative (shorter) fatigue life estimates. The crack growth rate (da/dN) was measured in a compact tension specimen material fatigue testing program. The test results included a range of ERW and EFW pipe materials with varying vintages and grades. The measured fatigue crack growth rate for the materials tested was found to be lower than that recommended by existing industry standards. This adds to the over conservatism of current approaches. The numerical simulation and materials testing results and related recommendations presented in this paper are compared to existing codified treatments to quantify the level of conservatism inherent in the current state of practice. Recommendations are provided to enhance the precision and better manage conservatism in fatigue crack growth rate calculations. Increased accuracy serves to improve integrity management and would be of interest to pipeline operators, consultants and regulators.

Fatigue Life Estimation Using Frequency Domain Technique and Probabilistic Linear Cumulative Damage Model

2020 ◽  
Author(s):  
Vagner Pascualinotto Junior ◽  
Diego Felipe Sarzosa Burgos
Keyword(s):  
Fatigue Life ◽  
Frequency Domain ◽  
Structural Component ◽  
Random Vibration ◽  
Fatigue Behavior ◽  
Pressure Vessels ◽  
Nuclear Industry ◽  
Material Behavior ◽  
Life Estimation ◽  
Fatigue Life Estimation

Abstract Engineering critical structures, such as pressure vessels and pipelines, are designed to withstand a variety of in-service loading specific to their intended application. Random vibration excitation is observed in most of the structural component applications in the offshore, aerospace, and nuclear industry. Likewise, fatigue life estimation for such components is fundamental to verify the design robustness assuring structural integrity throughout service. The linear damage accumulation model (Palmgren-Miner rule) is still largely used for damage assessment on fatigue estimations, even though, its limitations are well-known. The fact that fatigue behavior of materials exposed to cyclic loading is a random phenomenon at any scale of description, at a specimen scale, for example, fatigue initiation sites, inclusions, defects, and trans-granular crack propagation are hardly predicted, indicates that a probabilistic characterization of the material behavior is needed. In this work, the methodology was applied to a Titanium alloy structural component. Low alloyed titanium alloys have no tendency to corrosion cracking in high-temperature high-pressure water containing impurities of chloride and oxygen found in a steam generator of nuclear power plants. The inherent uncertainties of the fatigue life and fatigue strength of the material are characterized using the random fatigue limit (RFL) statistic method. Furthermore, a frequency domain technique is used to determine the response power spectrum density (PSD) function of a structural component subjected to a random vibration profile excitation. The fatigue life of the component is then estimated through a probabilistic linear damage cumulative model.

scholarly journals Fatigue life estimation under multi-axial random loading in light poles

2015 ◽  
Vol 37 ◽  
pp. 183
Author(s):  
Kazem Reza Kashyzadeh
Keyword(s):  
Fatigue Life ◽  
Random Vibration ◽  
Equivalent Stress ◽  
Loading Conditions ◽  
Random Loading ◽  
Life Estimation ◽  
Fatigue Life Estimation ◽  
Light Pole ◽  
Variable Wind ◽  
Random Vibration Analysis

In the present paper, fatigue life of light poles under multi-axial random loading based on the variable wind direction and speed has been studied. To achieve these purposes, light pole is simulated with all loading conditions in ABAQUS Software. To consider to the three storm days as the critical loading conditions, Random vibration analysis has been performed to obtain stress histories and equivalent stress. Finally, Calculate fatigue life of light pole by using Dirlik Theory.

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