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A signature analysis method for IC failure analysis

Description: A new method of signature analysis is presented and explained. This method of signature analysis can be based on either experiential knowledge of failure analysis, observed data, or a combination of both. The method can also be used on low numbers of failures or even single failures. It uses the Dempster-Shafer theory to calculate failure mechanism confidence. The model is developed in the paper and an example is given for its use. 9 refs., 5 figs., 9 tabs.
Date: October 1, 1996
Creator: Henderson, C.L. & Soden, J.M.
Partner: UNT Libraries Government Documents Department

The Hydrostatic Mooring System. Quarterly Report for the Period April-June 2000

Description: The following topics are summarized for the 2nd quarter of 2000: (1) We amended the structural design of the buoy, moving the horizontal bulkhead from the bottom to the top of the buoy. (2) We designed the main bearing using Hilman Rollers. We discarded a parallel design using Lubron slide bearings due to concerns about keeping dirt out of the sliding surfaces. (3) We performed a preliminary failure tree risk analysis for the system as required by ABS. (4) We made various drawings of the system and sub-components.
Date: July 15, 2000
Creator: Korsgaard, Jens
Partner: UNT Libraries Government Documents Department

First passage failure: Analysis alternatives

Description: Most mechanical and structural failures can be formulated as first passage problems. The traditional approach to first passage analysis models barrier crossings as Poisson events. The crossing rate is established and used in the Poisson framework to approximate the no-crossing probability. While this approach is accurate in a number of situations, it is desirable to develop analysis alternatives for those situations where traditional analysis is less accurate and situations where it is difficult to estimate parameters of the traditional approach. This paper develops an efficient simulation approach to first passage failure analysis. It is based on simulation of segments of complex random processes with the Karhunen-Loeve expansion, use of these simulations to estimate the parameters of a Markov chain, and use of the Markov chain to estimate the probability of first passage failure. Some numerical examples are presented.
Date: April 17, 2000
Partner: UNT Libraries Government Documents Department

On the importance of target materials interfaces during low speed impact

Description: We are conducting a Cooperative Research and Development Project under the sponsorship of the U.S. Department of Energy to determine the applicability of aluminum particulate reinforced alloy laminates to aircraft structures and for containment of aircraft engine turbine blades and debris due to catastrophic engine failure. Within this framework, we are studying the terminal interaction of projectiles impacting targets at speeds of 150- to 500 m/s. Our presentation focuses on a special series of experiments and computational physics analyses of 6061-T6 aluminum alloy targets in single plate and laminate form impacted by steel cylindrical projectiles. Four cases are examined, projectile impact into (1) a single plate, (2) three contiguous plates (frictional interfaces), (3) three contiguous plates separated by Teflon layers (frictionless interfaces), and (4) a spaced array of three plates. We found that the ratio of projectile kinetic energies just at target perforation for the highest to lowest critical projectile speeds over the four targets is 1.75. Considering that target areal density is held constant across the four targets, this is a dramatic result. 2 refs., 7 figs.
Date: July 1996
Creator: Gogolewski, R. P.; Cunningham, B. J.; Riddle, R.; Lesuer, D. & Syn, C.
Partner: UNT Libraries Government Documents Department

Supplemental Analysis to Support Postulated Events in Process Hazards Analysis for the HEAF

Description: The purpose of this report is to conduct a limit scope risk assessment by generating event trees for the accident scenarios described in table 4-2 of the HEAF SAR, ref 1. Table 4-2 lists the postulated event/scenario descriptions for non-industrial hazards for HEAF. The event tree analysis decomposes accident scenarios into basic causes that appear as branches on the event tree. Bold downward branches indicate paths leading to the accident. The basic causes include conditions, failure of administrative controls (procedural or human error events) or failure of engineered controls (hardware, software or equipment failure) that singly or in combination can cause an accident to occur. Event tree analysis is useful since it can display the minimum number of events to cause an accident. Event trees can address statistical dependency of events such as a sequence of human error events conducted by the same operator. In this case, dependent probabilities are used. Probabilities/frequencies are assigned to each branch. Another example of dependency would be when the same software is used to conduct separate actions such as activating a hard and soft crow bar for grounding detonator circuits. Generally, the first event considered in the event tree describes the annual frequency at which a specific operation is conducted and probabilities are assigned to the remaining branches. An exception may be when the first event represents a condition, then a probability is used to indicate the percentage of time the condition exists. The annual probability (frequency) of the end state leading to the accident scenario in the event tree is obtained by multiplying the branch probabilities together.
Date: July 20, 2001
Creator: Lambert, H & Johnson, G
Partner: UNT Libraries Government Documents Department

A Automated Tool for Supporting FMEAs of Digital Systems

Description: Although designs of digital systems can be very different from each other, they typically use many of the same types of generic digital components. Determining the impacts of the failure modes of these generic components on a digital system can be used to support development of a reliability model of the system. A novel approach was proposed for such a purpose by decomposing the system into a level of the generic digital components and propagating failure modes to the system level, which generally is time-consuming and difficult to implement. To overcome the associated issues of implementing the proposed FMEA approach, an automated tool for a digital feedwater control system (DFWCS) has been developed in this study. The automated FMEA tool is in nature a simulation platform developed by using or recreating the original source code of the different module software interfaced by input and output variables that represent physical signals exchanged between modules, the system, and the controlled process. For any given failure mode, its impacts on associated signals are determined first and the variables that correspond to these signals are modified accordingly by the simulation. Criteria are also developed, as part of the simulation platform, to determine whether the system has lost its automatic control function, which is defined as a system failure in this study. The conceptual development of the automated FMEA support tool can be generalized and applied to support FMEAs for reliability assessment of complex digital systems.
Date: September 7, 2008
Creator: Yue,M.; Chu, T.-L.; Martinez-Guridi, G. & Lehner, J.
Partner: UNT Libraries Government Documents Department


Description: Two high-pressure bioassay vessels failed at the Savannah River Site during a microwave heating process for biosample testing. Improper installation of the thermal shield in the first failure caused the vessel to burst during microwave heating. The second vessel failure is attributed to overpressurization during a test run. Vessel failure appeared to initiate in the mold parting line, the thinnest cross-section of the octagonal vessel. No material flaws were found in the vessel that would impair its structural performance. Content weight should be minimized to reduce operating temperature and pressure. Outer vessel life is dependent on actual temperature exposure. Since thermal aging of the vessels can be detrimental to their performance, it was recommended that the vessels be used for a limited number of cycles to be determined by additional testing.
Date: September 22, 2008
Creator: Vormelker, P
Partner: UNT Libraries Government Documents Department

Failure Modes and Diagnostic Signatures Working Group - Ignition Diagnostics Requirements Update

Description: We have performed an initial assessment of the sensitivity of various expected ignition diagnostic signatures to ignition failure modes using one and two-dimensional hydrodynamics simulations and post-processed simulated diagnostic output. As a result of this assessment, we recommend several changes to the current requirements for the ignition diagnostic suite. These recommendations are summarized in Table 1.
Date: March 26, 2007
Creator: Cerjan, C.; Haan, S.; Hatchett, S. & Koch, J.
Partner: UNT Libraries Government Documents Department


Description: At the Savannah River Site (SRS), a Department of Energy (DOE) installation in west-central South Carolina there is a unique geologic stratum that exists at depth that has the potential to cause surface settlement resulting from a seismic event. In the past the particular stratum in question has been remediated via pressure grouting, however the benefits of remediation have always been debatable. Recently the SRS has attempted to frame the issue in terms of risk via an event tree or logic tree analysis. This paper describes that analysis, including the input data required.
Date: May 25, 2009
Creator: Williams, R
Partner: UNT Libraries Government Documents Department


Description: This paper proposes an alternative methodology to determine the failure criteria for use in dynamic simulations of radioactive material shipping packages in the events of hypothetical accident conditions. The current stress failure criteria defined in the Nuclear Regulatory Guide 7.6 [1] and the ASME Code, Section III, Appendix F [2] for Level D Service Loads are based on the ultimate strength of uniaxial tensile test specimen rather than on the material fracture in the state of multi-axial stresses. On the other hand, the proposed strain-based failure criteria are directly related to the material failure mechanisms in multi-axial stresses. In addition, unlike the stress-based criteria, the strain-based failure criteria are applicable to the evaluation of cumulative damages caused by the sequential loads in the hypothetical accident events as required by the Nuclear Regulatory Guide 7.8 [4].
Date: May 1, 2008
Creator: Wu, T
Partner: UNT Libraries Government Documents Department

Ignition Failure Mode Radiochemical Diagnostics Initial Assessment

Description: Radiochemical diagnostic signatures are well known to be effective indicators of nuclear ignition and burn reaction conditions. Nuclear activation is already a reliable technique to measure yield. More comprehensively, though, important quantities such as fuel areal density and ion temperature might be separately and more precisely monitored by a judicious choice of select nuclear reactions. This report details an initial assessment of this approach to diagnosing ignition failures on point-design cryogenic National Ignition Campaign targets. Using newly generated nuclear reaction cross section data for Scandium and Iridium, modest uniform doping of the innermost ablator region provides clearly observable reaction product differences between robust burn and failure for either element. Both equatorial and polar tracer loading yield observable, but indistinguishable, signatures for either choice of element for the preliminary cases studied.
Date: April 20, 2007
Creator: Fortner, R; Bernstein, L; Cerjan, C; Haan, S W; Harding, R; Hatchett, S et al.
Partner: UNT Libraries Government Documents Department

Design of Experiments to Determine Causes of Flex Cable Solder Wicking, Discoloration and Hole Location Defects

Description: Design of Experiments (DoE) were developed and performed in an effort to discover and resolve the causes of three different manufacturing issues; large panel voids after Hot Air Solder Leveling (HASL), cable hole locations out of tolerance after lamination and delamination/solder wicking around flat flex cable circuit lands after HASL. Results from a first DoE indicated large panel voids could be eliminated by removing the pre-HASL cleaning. It also revealed eliminating the pre-HASL bake would not be detrimental when using a hard press pad lamination stackup. A second DoE indicated a reduction in hard press pad stackup lamination pressure reduced panel stretch in the y axis approximately 70%. A third DoE illustrated increasing the pre-HASL bake temperature could reduce delamination/solder wicking when using a soft press pad lamination stackup.
Date: April 22, 2009
Creator: Wolfe, Larry
Partner: UNT Libraries Government Documents Department

Predicting fracture in micron-scale polycrystalline silicon MEMS structures.

Description: Designing reliable MEMS structures presents numerous challenges. Polycrystalline silicon fractures in a brittle manner with considerable variability in measured strength. Furthermore, it is not clear how to use a measured tensile strength distribution to predict the strength of a complex MEMS structure. To address such issues, two recently developed high throughput MEMS tensile test techniques have been used to measure strength distribution tails. The measured tensile strength distributions enable the definition of a threshold strength as well as an inferred maximum flaw size. The nature of strength-controlling flaws has been identified and sources of the observed variation in strength investigated. A double edge-notched specimen geometry was also tested to study the effect of a severe, micron-scale stress concentration on the measured strength distribution. Strength-based, Weibull-based, and fracture mechanics-based failure analyses were performed and compared with the experimental results.
Date: September 1, 2010
Creator: Hazra, Siddharth S. (Carnegie Mellon University, Pittsburgh, PA); de Boer, Maarten Pieter (Carnegie Mellon University, Pittsburgh, PA); Boyce, Brad Lee; Ohlhausen, James Anthony; Foulk, James W., III & Reedy, Earl David, Jr.
Partner: UNT Libraries Government Documents Department

Operational tips for improving intrusion detection system performance

Description: The installation of a new intrusion detection system (IDS) is, of course, expected to improve site security. However, depending upon the way the system is used, it can, over time, actually degrade security. Proper use, control, and maintenance of the IDS is critical if site security is to be maintained. This paper discusses several operational issues that should be addressed in order to use an IDS effectively. Several anecdotes from the author`s experience are given to illustrate proper and improper use of an IDS. Improper operational use of an IDS can render it ineffective. Applying these tips can help keep the IDS operating at peak performance.
Date: September 1, 1996
Creator: Adams, D.G.
Partner: UNT Libraries Government Documents Department

Analysis of production line motor failure. CRADA final report for CRADA number Y-1293-0215

Description: The Oak Ridge National Laboratory (ORNL) was approached by a Food Products Manufacturer (FPM) to investigate the rapid failure of motors in a manufacturing facility. It was reported that some motors or their bearings were being replaced after as little as four months of service. The deciding symptom for replacement was always high motor vibration. To protect against unscheduled downtime in the middle of a process run, the FPM`s maintenance team removes a motor from service when its vibration level reaches a conservative threshold of approximately 0.4 inches per second. In their experience, motors left in service after reaching this vibration threshold can fail at any time within the time span of the next process run causing significant losses of raw material and production capacity. A peculiar finding of vibration level trend analysis was that at least one motor exhibited cyclic variations with 24-hour periodicity. The vibration level reached a maximum at about 4:00 a.m., ramped down during the day, and then rose again during the night. Another peculiarity was that most of the vibration energy in the affected motors was at the 120 Hz frequency. Since this is twice the 60 Hz line frequency the FPM suspected the vibration was electrically induced. The electric loads at the FPMs plant remain constant during the five days of a continuous production run. Thus, the periodicity of the vibration observed, with its daily peaking at about four am, suggested the possibility of being driven by changes in the electrical power grid external to the plant.
Date: February 10, 1995
Creator: Kueck, J. & Talbott, C.
Partner: UNT Libraries Government Documents Department

Creep failure analysis for ceramic composites containing viscous interfaces

Description: This paper describes an experimental and theoretical study of the creep fracture of advanced ceramic composites under steady axial tension. Such composites consist of a high fraction of elongated ceramic grains, varying substantially in aspect ratio and embedded in a glassy matrix phase. For creep testing, a model test system was prepared, which consisted of well-aligned elongated mica platelets ({approximately} 60 vol%) and residual glass phase ({approximately} 40 vol%) in its final heat-treatment stage. The creep curves of several specimens under various applied loads and at a temperature (800 C) higher than the T{sub g} of the glass matrix ({approximately} 650 C) were obtained up to creep fracture. Micrographs of the creep fracture surfaces revealed substantial grain pull-out and cavitation in the matrix phase with virtually no transgranular fracture. The objective of this work is to simulate the creep response and fracture based on the accumulation of localized void growth and microstructural parameters, using a computational mechanics technique, called viscous break interaction (VBI), developed to compute stress fields around strongly interacting fractures or voids in composites with fibrous microstructures. To simulate the creep process up to fracture, a Monte Carlo model is developed which couples VBI with a statistical description of grain length. Both the experimental and simulation results show that random lengths and random overlap of the aligned grains naturally lead to (i) local and microstructure-sensitive damage evolution up to ultimate failure and (ii) substantial variation in failure times of seemingly identical specimens.
Date: September 1, 1998
Creator: Beyerlein, I. J.; An, L. & Raj, R.
Partner: UNT Libraries Government Documents Department

A report on the seismic capacity of the General Laboratory and Administration Building at Los Alamos National Laboratory

Description: A seismic analysis of the General Laboratory and Administration Building at Los Alamos National Laboratory is performed. The analyses are performed in detail for one portion of the building and then qualitatively extrapolated to other portions of the building. Seismic capacities are evaluated based on two sets of acceptance criteria. The first is based on Code-type criteria and is associated with a low probability of failure. This capacity is found to be in the 0.04--0.06 G ZPA range (the free field seismic motion is defined with a NUREG 0098 response spectrum). The second capacity is based on much less conservative criteria such as might be associated with a high probability of failure. This capacity is found to be about 0.15 G. Finally structural modifications are proposed that would increase the low probability of failure capacity to 0.15 G ZPA. These modifications consist of steel double angle braces or concrete shear walls placed at some of the frames in the building.
Date: January 1, 1995
Creator: Miller, C.A.; Costantino, C.J.; Zhu, Y.; Wang, Y.K.; Shteyngart, S.; Xu, J. et al.
Partner: UNT Libraries Government Documents Department

Failure analysis for micro-electrical-mechanical systems (MEMS)

Description: Micro-Electrical Mechanical Systems (MEMS) is an emerging technology with demonstrated potential for a wide range of applications including sensors and actuators for medical, industrial, consumer, military, automotive and instrumentation products. Failure analysis (FA) of MEMS is critically needed for the successful design, fabrication, performance analysis and reliability assurance of this new technology. Many devices have been examined using techniques developed for integrated circuit analysis, including optical inspection, scanning laser microscopy (SLM), scanning electron microscopy (SEM), focused ion beam (FIB) techniques, atomic force microscopy (AFM), infrared (IR) microscopy, light emission (LE) microscopy, acoustic microscopy and acoustic emission analysis. For example, the FIB was used to microsection microengines that developed poor performance characteristics. Subsequent SEM analysis clearly demonstrated the absence of wear on gear, hub, and pin joint bearing surfaces, contrary to expectations. Another example involved the use of infrared microscopy for thermal analysis of operating microengines. Hot spots were located, which did not involve the gear or hub, but indicated contact between comb structures which drive microengines. Voltage contrast imaging proved useful on static and operating MEMS in both the SEM and the FIB and identified electrostatic clamping as a potentially significant contributor to failure mechanisms in microengines. This work describes MEMS devices, FA techniques, failure modes, and examples of FA of MEMS.
Date: October 1, 1997
Creator: Peterson, K.A.; Tangyunyong, P. & Barton, D.L.
Partner: UNT Libraries Government Documents Department

The Use of a Beryllium Hopkinson Bar to Characterize In-Axis and Cross-Axis Accelerometer Response in Shock Environments

Description: The characteristics of a piezoresistive accelerometer in shock environments have been studied at Sandia National Laboratories in the Mechanical Shock Laboratory. A beryllium Hopkinson bar capability with diameters of 0.75 in. and 2.0 in has been developed to extend our understanding of the piezoresistive accelerometer, in two mechanical configurations, in the high frequency, high shock environments where measurements are being made. The in-axis performance of the piezoresistive accelerometer determined from measurements with a beryllium Hopkinson bar and a certified laser doppler vibrometer as the reference measurement is presented. The cross-axis performance of the accelerometer subjected to static compression on a beryllium cylinder, static strain on a steel beam, dynamic strain on a steel beam (ISA-RP 37.2, Paragraph 6.6), and compressive shocks in a split beryllium Hopkinson bar configuration is also presented. The performance of the accelerometer in a combined in-axis and cross-axis shock environment is shown for one configuration. Finally, a failure analysis conducted in cooperation with ENDEVCO gives a cause for the occasional unexplained failures that have occurred in some applications.
Date: January 1, 1999
Creator: Bateman, V.I. & Brown, F.A.
Partner: UNT Libraries Government Documents Department

Failure analysis of a half-micron CMOS IC technology

Description: We present the results of recent failure analysis of an advanced, 0.5 {mu}m, fully planarized, triple metallization CMOS technology. A variety of failure analysis (FA) tools and techniques were used to localize and identify defects generated by wafer processing. These include light (photon) emission microscopy (LE), fluorescent microthermal imaging (FMI), focused ion beam cross sectioning, SEM/voltage contrast imaging, resistive contrast imaging (RCI), and e-beam testing using an IDS-5000 with an HP 82000. The defects identified included inter- and intra-metal shorts, gate oxide shorts due to plasma processing damage, and high contact resistance due to the contact etch and deposition process. Root causes of these defects were determined and corrective action was taken to improve yield and reliability.
Date: August 1, 1996
Creator: Liang, A.Y.; Tangyunyong, P.; Bennett, R.S. & Flores, R.S.
Partner: UNT Libraries Government Documents Department

Structural integrity and potential failure modes of hanford high-level waste tanks

Description: Structural Integrity of the Hanford High-Level Waste Tanks were evaluated based on the existing Design and Analysis Documents. All tank structures were found adequate for the normal operating and seismic loads. Potential failure modes of the tanks were assessed by engineering interpretation and extrapolation of the existing engineering documents.
Date: September 30, 1996
Creator: Han, F. C.
Partner: UNT Libraries Government Documents Department

Infrared light emission from semiconductor devices

Description: We present results using near-infrared (NIR) cameras to study emission of common defect classes for integrated circuits. The cameras are based on a liquid nitrogen cooled HgCdTe imaging array with high quantum efficiency and very low read noise. The array was developed for infrared astronomy and has high quantum efficiency in the wavelength range from 0.8 to 2.5 {mu}m. For comparison, the same set of samples used to characterize the performance of the NIR camera were studied using a non-intensified, liquid-nitrogen-cooled, slow scan CCD camera (with a spectral range 400-1100 nm). Results show that the NIR camera images all of the defect classes studied here with much shorter integration times than the cooled CCD, suggesting that photon emission beyond 1 {mu}m is significantly stronger than at shorter wavelengths.
Date: October 1, 1996
Creator: Barton, D.L.; Tangyunyong, P.; Soden, J.M.; Liang, A.Y.; Low, F.J.; Zaplatin, A.N. et al.
Partner: UNT Libraries Government Documents Department

Shock-wave properties of glass with implications for failure kinetics

Description: New, previously unpublished shock wave data on soda-lime glass are presented. These data are examined in light of recent experimental evidence for failure wave behavior in brittle solids. An underlying physical basis for failure waves is explored in terms of inelastic deformation kinetics processes.
Date: October 1996
Creator: Grady, D. & Chhabildas, L.
Partner: UNT Libraries Government Documents Department