Damage Accumulation and Life-Prediction Models for SnAgCu Leadfree Electronics Under Shock-Impact

2009 ◽  
Author(s):  
Pradeep Lall ◽  
Sandeep Shantaram ◽  
Arjun Angral ◽  
Mandar Kulkarni ◽  
Jeff Suhling
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Thermal Aging ◽  
Cohesive Zone ◽  
Life Prediction ◽  
Failure Modes ◽  
Damage Index ◽  
Image Correlation ◽  
Shock Impact ◽  
Cohesive Zone Elements

Relative damage-index based on the leadfree interconnect transient strain history from digital image correlation, explicit finite-elements, cohesive-zone elements, and component’s survivability envelope has been developed for life-prediction of two-leadfree electronic alloy systems. Life prediction of pristine and thermally-aged assemblies, have been investigated. Solder alloy system studied include Sn1Ag0.5Cu, and 96.5Sn3.5Ag. Transient strains during the shock-impact have been measured using digital image correlation in conjunction with high-speed cameras operating at 50,000 fps. Both the board strains and the package strains have been measured in a variety of drop orientations including JEDEC horizontal drop orientation, vertical drop orientation and intermediate drop orientations. In addition the effect of sequential stresses of thermal aging and shock-impact on the failure mechanisms has also been studied. The thermal aging condition used for the study includes 125°C for 100 hrs. The presented methodology addresses the need for life prediction of new lead-free alloy-systems under shock and vibration, which is largely beyond the state of art. Three failure modes have been predicted including interfacial failure at the copper-solder interface, solder-PCB interface, and the solder joint failure. Explicit non-linear finite element models with cohesive-zone elements have been developed and correlated with experimental results. Velocity data from digital image correlation has been used to drive the attachment degrees of freedom of the submodel and extract transient interconnect strain histories. Explicit finite-element sub-modeling has been correlated with the full-field strain in various locations, orientations, on both the package and the board-side. The survivability of the leadfree interconnections under sequential loading (thermal aging and shock-impact) from simulation has been compared with pristine circuit assemblies subjected to shock-impact. Sequential loading changes the failure modes and decreases the drop reliability as compared to the room temperature experimental results. Damage index based survivability envelope is intended for component integration to ensure reliability in harsh environments.

scholarly journals Mixed-mode cohesive zone parameters from integrated digital image correlation on micrographs only

2019 ◽  
Vol 156-157 ◽  
pp. 179-193 ◽  
Author(s):  
A.P. Ruybalid ◽  
J.P.M. Hoefnagels ◽  
O. van der Sluis ◽  
M.P.F.H.L. van Maris ◽  
M.G.D. Geers
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Cohesive Zone ◽  
Mixed Mode ◽  
Image Correlation ◽  
Zone Parameters ◽  
Integrated Digital Image Correlation

scholarly journals Analysis for Shear Behavior of SRC Deep Beams Based on Tests, Digital Image Correlation Technique, and Finite Elemental Simulation

2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Buqing Chen ◽  
Jun Wu ◽  
Changjun Liu ◽  
Yanhua Liu ◽  
Wenmei Zhou ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Failure Modes ◽  
Parameter Analysis ◽  
Image Correlation ◽  
Superposition Method ◽  
Deep Beams ◽  
Shear Span ◽  
Depth Ratio ◽  
Dic Technique

Seven steel-reinforced concrete (SRC) deep beams were tested to investigate the shear performance, including peak loads, failure modes, mid-span deflections, and cracking patterns. The parameters include the shear span-to-depth ratio and the dimensions of the steel skeleton. The digital image correlation (DIC) technique was utilized for real-time recording of the in-plane strain and deformation. The experiment results show that the failure modes of specimens could be concluded as two forms: diagonal compression failure and shear failure. The DIC technique was proved to be efficient for tracking the development of crack patterns and recording the failure modes. The corresponding numerical analyses based on experiments were carried out and demonstrated to be a reliable method to simulate the shear response. Furthermore, the most significant parameters and their interactions were identified by finite element models parameter analysis. The steel skeleton height and shear span-to-depth ratio were the main parameters affecting shear capacity. A design formula based on the strength superposition method was presented. The calculated results were basically in agreement with the test results, where the mean and coefficient of variation were 1.04 and 0.09, respectively.

scholarly journals Developing Dynamic Digital Image Correlation Technique to Monitor Structural Damage of Old Buildings under External Excitation

2014 ◽  
Vol 2014 ◽  
pp. 1-15 ◽  
Author(s):  
Ming-Hsiang Shih ◽  
Wen-Pei Sung
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Structural Damage ◽  
Damage Index ◽  
Correlation Method ◽  
Image Correlation ◽  
Correlation Technique ◽  
Frequency Change ◽  
External Excitation ◽  
Structural Reinforcement

The capacity of buildings to resist external excitation is an important factor to consider for the structural design of buildings. When subject to external excitation, a building may suffer a certain degree of damages, and its residual capacity to resist external excitation cannot be evaluated. In this research, dynamic digital image correlation method combined with parameter evaluation available in system identification is used to evaluate the structural capacity to resist external excitation. The results reveal possible building latent safety problems so that timely structural reinforcement or dismantling of the building can be initiated to alleviate further damages. The results of experiments using the proposed method conform to the results obtained using the conventional method, but this method is more convenient and rapid than the latter in the subsequent procedure of data processing. If only the frequency change is used, the damages suffered by the building can be detected, but the damage location is not revealed. The interstory drift mode shape (IDMS) based on the characteristic of story drift has higher sensitivity than the approximate story damage index (ADSI) method based on modal frequency and vibration type; however, both indices can be used to determine the degree and location of building damages.

On the Use of Digital Image Correlation (DIC) for Evaluating the Tensile Behaviour of BFRCM Strips

2019 ◽  
Vol 817 ◽  
pp. 377-384 ◽  
Author(s):  
Jennifer D'Anna ◽  
Giuseppina Amato ◽  
Jian Fei Chen ◽  
Giovanni Minafò ◽  
Lidia La Mendola
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Failure Modes ◽  
Image Correlation ◽  
Tensile Behaviour ◽  
Vapour Permeability ◽  
Cementitious Matrix ◽  
Frp Composites ◽  
Tensile Response ◽  
Tensile Characterization

Fibre Reinforced Cementitious Matrix (FRCM) composites are becoming largely adopted for retrofitting masonry structures. These materials offer several advantages in comparison to Fibre Reinforced Polymer (FRP) composites, such as good resistance to fire and high temperatures, vapour permeability, possibility to be applied on wet surfaces, higher compatibility with the masonry substrate. However, the tensile behavior of FRCM materials is more complex compared to FRP composites, due to the limited tensile strength of the cement-based matrix. For this reason, FRCM materials require appropriate tensile characterization and, in this context, the use of non-conventional measurement systems, such as the Digital Image Correlation (DIC), can offer numerous advantages. This work presents an experimental study on the application of the DIC technique for the tensile characterization of Basalt Fibre Reinforced Cementitious Matrix (BFRCM) strips. Tensile tests were carried out on three series of specimens reinforced with one, two or three layers of basalt grid in order to investigate the effect of the reinforcement ratio on the tensile response of the composite strips. The test setup and the calibration of the DIC analyses are discussed. It is shown as the DIC allows obtaining detailed information on the tensile response, including the evaluation of the full strain field on the surface of the BFRCM strips and the location of cracks. Results are discussed also in terms of stress-strain curves and failure modes.

Creep-fatigue life prediction of perforated copper-alloy plate by using Digital Image Correlation Method

2018 ◽  
Vol 2018 (0) ◽  
pp. J0320104
Author(s):  
Tatsuya KAMEYAMA ◽  
Takumi TOKIYOSHI ◽  
Chikako KATOU ◽  
Toshihide IGARI ◽  
Hiroyuki KOBAYASHI ◽  
...  
Keyword(s):  
Fatigue Life ◽  
Digital Image Correlation ◽  
Digital Image ◽  
Copper Alloy ◽  
Life Prediction ◽  
Correlation Method ◽  
Fatigue Life Prediction ◽  
Image Correlation ◽  
Alloy Plate ◽  
Creep Fatigue
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