Damage Proxies Research Articles

Rapid Damage Mapping for the 2015Mw 7.8 Gorkha Earthquake Using Synthetic Aperture Radar Data from COSMO–SkyMed and ALOS-2 Satellites

The 25 April 2015 M_w 7.8 Gorkha earthquake caused more than 8000 fatalities and widespread building damage in central Nepal. The Italian Space Agency’s COSMO–SkyMed Synthetic Aperture Radar (SAR) satellite acquired data over Kathmandu area four days after the earthquake and the Japan Aerospace Exploration Agency’s Advanced Land Observing Satellite-2 SAR satellite for larger area nine days after the mainshock. We used these radar observations and rapidly produced damage proxy maps (DPMs) derived from temporal changes in Interferometric SAR coherence. Our DPMs were qualitatively validated through comparison with independent damage analyses by the National Geospatial-Intelligence Agency and the United Nations Institute for Training and Research’s United Nations Operational Satellite Applications Programme, and based on our own visual inspection of DigitalGlobe’s WorldView optical pre- versus postevent imagery. Our maps were quickly released to responding agencies and the public, and used for damage assessment, determining inspection/imaging priorities, and reconnaissance fieldwork.

Should low birth-weight be considered a relevant risk factor for rise in pulse pressure among adult overweight-obese subjects?

Low birth-weight (BW) is related to rise in blood pressure (BP) later in life. Aim of this study is investigating whether presence of overweight-obesity modifies this relationship, independently from any additional correlate of metabolic syndrome. We studied 535 (216 M/319 F) otherwise healthy overweight-obese people (body mass index≥25 kg/m<sup>2</sup>), recording systolic, diastolic and pulse BP as well as plasma glucose and lipids, additionally interviewing them about BW and weight-change after age of 18 years. The reciprocal of BW was related only to pulse pressure (PP, r=0.14; P=0.04), uniquely in men and individuals with BW≤2500 g had a higher relative risk of having PP above upper quartile (>60 mmHg), independently of sex. After adjusting for confounders each 1 kg rise in BW was associated with 2.84±0.88 (standard error) mmHg decrease in PP; P=0.0042. Moreover, again only among males, the lower BW the higher was the risk of a PP>60 mmHg [odds ratio (95% confidence interval): 2.43 (1.39-4.24); P=0.0018]. In conclusion BW was inversely related only with PP in overweight-obese subjects, uniquely in men, being such effect independent from other correlates of metabolic syndrome. Since elevated PP can be considered a proxy of vascular damage, these findings further stress the importance of inquiring about BW to better stratify the risk of vascular damage, in adult overweight-obese individuals.

UV SURFACE ENVIRONMENT OF EARTH-LIKE PLANETS ORBITING FGKM STARS THROUGH GEOLOGICAL EVOLUTION

The UV environment of a host star affects the photochemistry in the atmosphere, and ultimately the surface UV environment for terrestrial planets and therefore the conditions for the origin and evolution of life. We model the surface UV radiation environment for Earth-sized planets orbiting FGKM stars at the 1AU equivalent distance for Earth through its geological evolution. We explore four different types of atmospheres corresponding to an early Earth atmosphere at 3.9 Gyr ago and three atmospheres covering the rise of oxygen to present day levels at 2.0 Gyr ago, 0.8 Gyr ago and modern Earth (Following Kaltenegger et al. 2007). In addition to calculating the UV flux on the surface of the planet, we model the biologically effective irradiance, using DNA damage as a proxy for biological damage. We find that a pre-biotic Earth (3.9 Gyr ago) orbiting an F0V star receives 6 times the biologically effective radiation as around the early Sun and 3520 times the modern Earth-Sun levels. A pre-biotic Earth orbiting GJ 581 (M3.5V) receives 300 times less biologically effective radiation, about 2 times modern Earth-Sun levels. The UV fluxes calculated here provide a grid of model UV environments during the evolution of an Earth-like planet orbiting a range of stars. These models can be used as inputs into photo-biological experiments and for pre-biotic chemistry and early life evolution experiments.

The local impact of typhoons on economic activity in China: A view from outer space

We examine the impact of typhoons on local economic activity in coastal China. To capture potential damages from an individual typhoon we use historical typhoon track data in conjunction with a detailed wind-field model. We then combine our damage proxy with satellite derived nightlight intensity data to construct a panel data set that allows us to estimate the impact of typhoons at a spatially highly disaggregated level (approx. 1km). Our results show that typhoons have a negative and significant, but short-term, impact on local activity – a typhoon that is estimated to destroy 50% of the property reduces local economic activity by 20% for that year. Over our period of analysis (1992–2010) total net economic losses are estimated to be in the region of $US 28.34 billion. To assess the damage risk from future typhoons we use simulated probability distributions of typhoon occurrence and intensity and combine these with our estimated effects. Results suggest that expected annual losses are likely to be around $US 0.54 billion.

Structural damage diagnosis using frequency response functions and orthogonal matching pursuit: theoretical development

Summary A structural damage diagnosis procedure that directly uses the frequency response function is developed. Frequency response data from a possibly damaged system and a finite element model of the healthy system are used to form a damage residual—a mathematical proxy or signature of structural damage. This damage residual can be calculated in the presence of incomplete measurements and at multiple frequencies. A system of equations is then formed, which relates the damage residual to the actual damage on each element represented as a fractional stiffness loss. Therefore, only damage affecting the stiffness properties of the structure is considered here. Classical dynamic model condensation is used in the formation of these equations to overcome the coordinate mismatch created by the incomplete measurement problem. The system of equations created using the damage residual is usually overdetermined and subject to noise, error as a result of the model reduction, and general ill-conditioning. To overcome these issues, a method known as orthogonal matching pursuit is used to solve the equations for the percent damage. Orthogonal matching pursuit is a method of sparse recovery that solves for the damage in terms of the fewest number of elements. Simulation studies are performed on a truss structure. The damage diagnosis method is shown to accurately identify multiple damage cases. Copyright © 2014 John Wiley & Sons, Ltd.

Retention of deuterium in damaged low-activation steel Rusfer (EK-181) after gas and plasma exposure

Reduced-activation ferritic–martensitic steels (RAFMS) are advanced structural materials for the construction of future fusion reactors with high fluxes of neutrons, such as DEMO or a Fusion Neutron Source (FNS).In the present work the influence of different damages on deuterium retention in the RAFM Rusfer (Chernov et al., 2007) was investigated. Three different types of damage were applied:(i)irradiation by 20MeV W6+ ions to a damage fluence of 0.89dpa (1.4×1018ions/m2). Tungsten ion irradiation was used as proxy for displacement damage created by neutrons;(ii)heat loads in the QSPA-T facility with 10 pulses of 0.5MJ/m2 with a duration of 0.5ms;(iii)low-temperature hydrogen plasma irradiation in the LENTA facility at 320 and 600K to a fluence of 1025H/m2.The hydrogen isotope retention properties of the damaged and undamaged material were investigated by exposure to deuterium gas several weeks after damaging. The deuterium retention was investigated in the temperature range of RT–773K at pressure 104Pa. Deuterium depth profiles were measured a month after gas exposure by nuclear reaction analysis (NRA) using the D(3He,p)α nuclear reaction. Deuterium retention in damaged and undamaged Rusfer in the temperature range of 300–600K has a maximum at 500K for all types of damage investigated. The typical value of deuterium concentration in the bulk is 10−3at.%. Peculiarities of D retention in damaged samples are discussed.

Higher serum S100B and BDNF levels are correlated with a lower pressure-pain threshold in fibromyalgia.

BackgroundFibromyalgia (FM) is conceptualized as a central sensitization (CS) condition, that presents high serum brain-derived neurotrophic factor (BDNF) and neuroglia activation. Although the S100B protein regulates neuroglia functions, it has been traditionally used as a proxy of central nervous system damage. However, neither BDNF nor S100B association with the clinical picture of FM has been elucidated. To explore their association with the pressure-pain threshold (PPT) in FM, we performed a cross-sectional study, including 56 females with confirmed FM aged 18–65 years. Linear regression models were used to adjust for potential confounding factors between serum BDNF, S100B and PPT.ResultsSerum BDNF and S100B were correlated (Spearman’s Rho = 0.29). Serum BDNF (log) and S100B (log) were correlated with the PPT (log) (Partial η2 = 0.129, P = 0.012 for the BDNF (log), and Partial η2 = 0.105, P = 0.025 for the S100B (log)). Serum BDNF (log) was inversely associated with PPT (log) (β = -1.01, SE = 0.41), age (β = -0.02, SE = 0.15) and obsessive compulsive disorder (β = -0.36, SE = 0.15), while serum S100B (log) was inversely associated with PPT (log) (β = -1.38, SE = 0.50), only.ConclusionsBoth neuroglia key mediators in the CS process were inversely correlated with the PPT. Serum assessment of BDNF and S100B deserve further study to determine its potential as a proxy for the CS spectrum in FM.

Environmental controls of frost cracking revealed through in situ acoustic emission measurements in steep bedrock

Frost cracking, the breakdown of rock by freezing, is one of the most important mechanical weathering processes acting on Earth's surface. Insights on the mechanisms driving frost cracking stem mainly from laboratory and theoretical studies. Transferring insights from such studies to natural conditions, involving jointed bedrock and heterogeneous thermal and hydrological properties, is a major challenge. We address this problem with simultaneous in situ measurements of acoustic emissions, used as proxy of rock damage, and rock temperature/moisture content. The 1 year data set acquired in an Alpine rock wall shows that (1) liquid water content has an important impact on freezing‐induced rock damage, (2) sustained freezing can yield much stronger damage than repeated freeze‐thaw cycling, and (3) that frost cracking occurs over the full range of temperatures measured extending from 0 down to −15°C. These new measurements yield a slightly different picture than previous field studies where ice segregation appears to play an important role.

Extended Kalman Filter Models and Resistance Spectroscopy for Prognostication and Health Monitoring of Leadfree Electronics Under Vibration

A technique has been developed for monitoring the structural damage accrued in ball grid array interconnects during operation in vibration environments. The technique uses resistance spectroscopy based state space vectors, rate of change of the state variable, and acceleration of the state variable in conjunction with extended Kalman filter, and is intended for the pre-failure time-history of the component. Condition monitoring using the presented technique can provide knowledge of impending failure in high reliability applications where the risks associated with loss-of-functionality are too high to bear. The methodology has been demonstrated on 96.5%Sn3.0%Ag0.5%Cu (SAC305) lead-free area-array electronic assemblies subjected to vibration. The future state of the system has been estimated based on a second order extended Kalman filter model and a Bayesian Framework. The measured state variable has been related to the underlying interconnect damage using plastic strain. Performance of the prognostication health management algorithm during the vibration test has been quantified using performance evaluation metrics. Model predictions have been correlated with experimental data. The presented approach is applicable to functional systems where corner interconnects in area-array packages may be often redundant. Prognostic metrics including α-λ metric, beta, and relative accuracy have been used to assess the performance of the damage proxies. The presented approach enables the estimation of residual life based on level of risk averseness.

Prognostics Health Management of Electronic Systems Under Mechanical Shock and Vibration Using Kalman Filter Models and Metrics

Structural damage to ball grid array interconnects incurred during vibration testing has been monitored in the prefailure space using resistance spectroscopy-based state space vectors, rate of change of the state variable, and acceleration of the state variable. The technique is intended for condition monitoring in high reliability applications where the knowledge of impending failure is critical and the risks in terms of loss of functionality are too high to bear. Future state of the system has been estimated based on a second-order Kalman Filter model and a Bayesian Framework. The measured state variable has been related to the underlying interconnect damage in the form of inelastic strain energy density. Performance of the prognostic health management algorithm during the vibration test has been quantified using performance evaluation metrics. The methodology has been demonstrated on leadfree area-array electronic assemblies subjected to vibration. Model predictions have been correlated with experimental data. The presented approach is applicable to functional systems where corner interconnects in area-array packages may be often redundant. Prognostic metrics including α - λ precision, β accuracy, and relative accuracy have been used to assess the performance of the damage proxies. The presented approach enables the estimation of residual life based on level of risk averseness.

Assessment of Accrued Damage and Remaining Useful Life in Leadfree Electronics Subjected to Multiple Thermal Environments of Thermal Aging and Thermal Cycling

Electronic systems are often stored for long periods prior to deployment in the intended environment. Aging has been previously shown to effect the reliability and constitutive behavior of second-level leadfree interconnects. Deployed systems may be subjected to cyclic thermo-mechanical loads subsequent to deployment. Prognostication of accrued damage and assessment of residual life is extremely critical for ultrahigh reliability systems in which the cost of failure is too high. The presented methodology uses leading indicators of failure based on microstructural evolution of damage to identify impending failure in electronic systems subjected to sequential stresses of thermal aging and thermal cycling. The methodology has been demonstrated on area-array ball-grid array test assemblies with Sn3Ag0.5Cu interconnects subjected to thermal aging at 125 °C and thermal cycling from -55 to 125 °C for various lengths of time and cycles. Damage equivalency methodologies have been developed to map damage accrued in thermal aging to the reduction in thermo-mechanical cyclic life based on damage proxies. Assemblies have been prognosticated to assess the error with interrogation of system state and assessment of residual life. Prognostic metrics including α - λ metric, sample standard deviation, mean square error, mean absolute percentage error, average bias, relative accuracy (RA), and cumulative RA have been used to compare the performance of the damage proxies.

Damage Detection in Pipes under Changing EnvironmentalConditions Using Embedded Piezoelectric Transducers and Pattern RecognitionTechniques

This paper presents the preliminary results of a research project that investigates the feasibility of continuous monitoring techniques using piezoelectric transducers (PZTs) permanently installed on steel pipes. The ultrasonic waves generated by PZTs are multimodal and dispersive. Therefore, it is difficult to detect changes created by the presence of damage, and it is even more difficult to differentiate changes produced by damage from benign changes produced by variation in environmental and operational conditions. In this paper, the results are reported of applying pattern recognition techniques to detect a mass scatterer (a proxy for damage) under ambient variations primarily due to varying internal pressure of a pipe. Using wavelet methods, 303 features are extracted, and adaptive boosting, modified adaptive boosting, and support vector machines for damage detection are employed. The performances of the three classifiers are evaluated over 41 trials with different combinations of training and testing data, resulting in the average accuracies of 85, 89, and 94%, respectively. Finally, the effectiveness of wavelet processing and features selected are discussed.

Site-Structure Resonance as a Proxy for Structural Damage

Since 1992, the reconnaissance teams of the German Task Force for Earthquakes have undertaken numerous field missions to disaster areas after strong earthquakes worldwide. During these missions, a unique database of damage cases has been collected, which serves as the basis for examining whether site-structure resonance effects contribute to building damage. The selected buildings that partly experienced slight to moderate damage during a recent major event have been experimentally tested in order to identify their structural parameters and to allow a calibration of the structural building models. In addition, instrumental noise recordings were made directly at the building sites to derive the ranges of predominant site periods. By correlating the ranges of predominant site periods with the building's capacity curves, representing the inelastic displacement behavior under lateral effects, a quick survey procedure has been developed to estimate the impact of agreements between periods of the site and the structure contributing to structural earthquake damage.

Prognostics Health Monitoring (PHM) for Prior Damage Assessment in Electronics Equipment Under Thermo-Mechanical Loads

Methodologies for prognostication and health monitoring (HM) can significantly impact electronic reliability for applications in which even minimal risk of failure may be unbearable. Presently, HM approaches such as the built-in self-test are based on reactive failure diagnostics and unable to determine residual-life (RL) or estimate residual-reliability. Prognostics health-monitoring (PHM) approach presented in this paper is different from state-of-art diagnostics and resides in the prefailure-space of the electronic system, in which no macro-indicators such as cracks or delamination exist. Applications for the presented PHM framework include, consumer and defense applications such as automotive safety systems including front and rear impact protection systems, chassis-control systems, x-by-wire systems, and defense applications such as avionics systems, naval electronic warfare systems. The presented PHM methodologies enable the estimation of prior damage in deployed electronics by the interrogation of the system state for systems in which the prior stress-history may be unknown or unavailable. The primary focus is on thermo-mechanical stresses. The presented methodologies will trigger repair or replacement, significantly prior to failure. The approach involves the use of condition monitoring devices which can be interrogated for damage proxies at finite time-intervals. The system's residual life is computed based on residual-life computation algorithms. Previously, we have developed several leading indicators of failure. In this paper, a mathematical approach has been presented to calculate the prior damage in electronics subjected to cyclic and isothermal thermo-mechanical loads. Electronic components operating in a harsh environment may be subjected to both temperature variations in addition to thermal aging during use-life. Data have been collected for leading indicators of failure for 95.5Sn4Ag0.5Cu first-level interconnects under both single and sequential applications of cyclic and isothermal thermo-mechanical loads. Methodology for the determination of prior damage history has been presented using non-linear least-squares method based on interrogation techniques. The methodology presented used the Levenberg-Marquardt Algorithm. The test vehicle includes various area-array packaging architectures soldered on immersion Ag finish, subjected to thermal cycling in the range of -40 οC to 125 οC and isothermal aging at 125 οC.

Prognostication of Residual Life and Latent Damage Assessment in Lead-Free Electronics Under Thermomechanical Loads

Requirements for system availability for ultrahigh reliability electronic systems such as airborne and space electronic systems are driving the need for advanced health monitoring techniques for the early detection of the onset of damage. Aerospace electronic systems usually face a very harsh environment, requiring them to survive the high strain rates, e.g., during launch and reentry, and thermal environments, including extremely low and high temperatures. Traditional health monitoring methodologies have relied on reactive methods of failure detection often providing little or no insight into the remaining useful life of the system. In this paper, a mathematical approach for the interrogation of the system state under cyclic thermomechanical stresses has been developed for six different lead-free solder alloy systems. Data have been collected for leading indicators of failure for alloy systems, including Sn3Ag0.5Cu, Sn0.3Ag0.7Cu, Sn1Ag0.5Cu, Sn0.3Ag0.5Cu0.1Bi, Sn0.2Ag0.5Cu0.1Bi0.1Ni, and 96.5 Sn3.5Ag second-level interconnects under the application of cyclic thermomechanical loads. The methodology presented resides in the prefailure space of the system in which no macroindicators such as cracks or delamination exist. Systems subjected to thermomechanical damage have been interrogated for the system state and the computed damage state correlated with the known imposed damage. The approach involves the use of condition monitoring devices which can be interrogated for damage proxies at finite time intervals. The interrogation techniques are based on the derivation of damage proxies and system prior-damage-based nonlinear least square methods, including the Levenberg-Marquardt algorithm. The system's residual life is computed based on residual-life computation algorithms.

Photosynthetic Potential and its Association with Lipid Peroxidation in Response to High Temperature at Different Leaf Ages in Maize

High temperature generally constrains plant growth and photosynthesis in many regions of the world; however, little is known about how photosynthesis responds to high temperature with regard to different leaf ages. The synchronous changes in gas exchange and chlorophyll fluorescence at three leaf age levels (just fully expanded, mature, and older leaves) of maize (Zea mays L.) were determined at three temperatures (30°C as a control and 36 and 42°C as the higher temperatures). High temperature significantly decreased the net CO2 assimilation rate (A), stomatal conductance (g s), maximal efficiency of photosystem II (PSII) photochemistry (F v/F m), efficiency of excitation energy capture by open PSII reaction centers (\( F^{\prime}_{\text{v}} /F^{\prime}_{\text{m}} \)), photochemical quenching of variable chlorophyll fluorescence (q P), and the electron transport rate (ETR), whereas minimal fluorescence yield (F 0) and nonphotochemical quenching of variable chlorophyll fluorescence (q N) were increased. The youngest fully expanded leaves had higher A, ETR, and q P compared with older leaves. Higher temperature with old leaves led to significant malondialdehyde (MDA) accumulation, a proxy for lipid peroxidation damage from active oxygen species (AOS). MDA content was significantly negatively correlated with A, F v/F m, \( F^{\prime}_{\text{v}} /F^{\prime}_{\text{m}} \), and q P. Thus, the results suggest that photosynthetic potentials, including stomatal regulation and PSII activity, may be restricted at high temperature, together with increasing cell peroxidation, which may be closely associated with leaf age.

Kilometer-scale Spatial Variation in Prevalence of the Rhizocephalan Lernaeodiscus porcellanae on the Porcelain Crab Petrolisthes cabrilloi

Abstract We studied spatial variation in the prevalence of the rhizocephalan barnacle Lernaeodiscus porcellanae on its porcelain crab host, Petrolisthes cabrilloi, at four southern California intertidal sites separated by only a few km. The prevalence of rhizocephalan externae varied significantly among sites in 2008-2009, with the southernmost site, White Point, consistently showing higher prevalence than the others. Externa prevalence was a good proxy of estimated true prevalence, i.e., the prevalence of rhizocephalans as a whole, not just those that had formed externae. We examined several hypotheses that might explain the observed spatial variation in prevalence. Host susceptibility to infection (indicated by the proxy of damage to host limbs, some of which are used to remove parasite infective stages), did not differ among sites. At all sites, prevalence was slightly higher in female crabs than in males, and the sex ratio at White Point was slightly female-biased while that at the other sites was mal...

Design Envelopes and Optical Feature Extraction Techniques for Survivability of SnAg Lead-free Packaging Architectures Under Shock and Vibration

In this paper, a design-envelope approach based on optical feature extraction techniques has been investigated for drop and shock survivability of electronic packaging has been presented for 6-lead-free solder alloy systems. Solder alloy systems investigated include, Sn1Ag0.5Cu, Sn3Ag0.5Cu, Sn0.3Ag0.7Cu, Sn0.3Ag0.7Cu0.1Bi, Sn0.2Ag0.7Cu0.1Bi-0.1Ni, 96.5Sn 3.5Ag. Previously, digital image correlation (DIC) has been used for measurement of thermally induced deformation and material-characterization. In this paper, DIC has been used for transient dynamic measurements, and optical feature extraction. Board assemblies have been subjected to shock-impact in various orientations including the JEDEC zero-degree drop and the vertical free-drop. Transient deformation has been measured using both digital image correlation and the strain gages. Measurements have been taken on both the package and the board side of the assemblies. Accuracy of high-speed optical measurement has been compared with that from discrete strain gages. Package architectures examined include-flex ball-grid arrays, tape-array ball-grid arrays, and metal lead-frame packages. Explicit finite-element models have been developed and correlated with experimental data. Models developed include, smeared property models, and Timoshenko-beam models. The potential of damage identification and tracking for various solder alloys has been investigated. Data on identification of damage proxies for competing failure mechanisms at the copper-to-solder, solder-to-printed circuit board, and copper-to-package substrate has been presented. Design envelopes have been developed based on statistical pattern recognition. The design-envelope is intended for component integration to ensure survivability in shock and vibration environments at a user-specified confidence level.

Prognostication of system-state in lead-free electronics equipment under cyclic and steady-state thermo-mechanical loads

In this paper, a mathematical approach for interrogation of system-state under cyclic thermo-mechanical stresses has been developed for three-different lead-free solder alloy systems. Data have been collected for leading indicators-of-failure for alloy systems including, Sn1Ag0.5Cu, Sn3Ag0.5Cu, Sn4Ag0.5Cu second-level interconnects under the application of cyclic thermo-mechanical loads. Methodology presented resides in the pre-failure space of the system in which no macro-indicators such as cracks or delamination exist. Systems subjected to thermo-mechanical damage have been interrogated for system state and the computed damage state correlated with known imposed damage. The approach involves the use of condition monitoring devices which can be interrogated for damage proxies at finite time-intervals. Interrogation techniques are based on non-linear least-squares methods. Various techniques including the Levenberg–Marquardt Algorithm have been investigated. The system’s residual life is computed based on residual-life computation algorithms. Detection of system-state significantly prior to catastrophic failure can significantly impact the reliability and availability of electronic systems. Requirements for system availability for ultra-high reliability electronic systems are driving the need for advanced heath monitoring techniques for early detection of onset of damage. Traditional health monitoring methodologies have relied on reactive methods of failure detection often providing little on no insight into the remaining useful life of the system.

Damage Progression Using Speckle‐Correlation and High‐Speed Imaging for Survivability of Leadfree Packaging Under Shock

Abstract: In this paper, a methodology to predict failure of electronics under shock and vibration loads has been investigated. Reliability prediction models have been developed using optical feature extraction techniques for 6‐leadfree solder alloy systems. Solder alloy systems investigated include, Sn1Ag0.5Cu, Sn3Ag0.5Cu, Sn0.3Ag0.7Cu, Sn0.3Ag0.7Cu0.1Bi, Sn0.2Ag0.7Cu0.1Bi‐0.1Ni, 96.5Sn3.5Ag. Previously, Digital Image Correlation (DIC) has been used for measurement of thermally‐induced deformation and material characterisation. In this paper, DIC has been used for transient dynamic measurements, and optical feature extraction. Board assemblies have been subjected to shock‐impact in various orientations including the zero‐degree JEDEC drop and the vertical free‐drop. Transient deformation has been measured using both DIC and the strain gages. Measurements have been taken on both the package and the board side of the assemblies. Accuracy of high‐speed optical measurement has been compared with that from discrete strain gages. Package architectures examined include‐flex ball‐grid arrays, tape‐array ball‐grid arrays, and metal lead‐frame packages. Explicit finite‐element models have been developed and correlated with experimental data. Three models were developed: smeared property models: Timoshenko‐beam models: and explicit sub‐models. The potential of damage identification and tracking for various solder alloys has been investigated. Data on the identification of damage proxies for competing failure mechanisms at the copper‐to‐solder, solder‐to‐printed circuit board, and copper‐to‐package substrate has been presented. Design envelopes have been developed based on Statistical Pattern Recognition (SPR). The design‐envelope is intended for component integration to ensure survivability in shock and vibration environments at a user‐specified confidence level.