Wear-out Failure Research Articles

Disproportionality analysis of cardiac adverse events associated with lenvatinib using the Japanese Adverse Drug Event Report database.

This study was conducted to examine disproportionality, times to onset, incidence rates and outcomes of lenvatinib-associated cardiac adverse events (AEs) using the Japanese Adverse Drug Event Report database. We analysed data for the period between April 2004 and May 2023. Data on cardiac AEs were extracted and the relative disproportionality of AEs was estimated using reporting odds ratios (RORs). Furthermore, Weibull distribution parameters were calculated. Of the 2 230 863 reports analysed, we identified 7684 reports of AEs associated with lenvatinib, including 317 cardiac AEs. Signals were detected for eight cardiac AEs: hypertension, cardiac failure, myocarditis, myocardial infarction, immune-mediated myocarditis, cardiomyopathy, angina unstable and cardiotoxicity. Among these, fatal outcomes were observed for cardiac failure, myocarditis and myocardial infarction. Histograms of median times to onset for the eight detected cardiac AE signals showed that AEs occurred at a median of 3.5-134.5days after lenvatinib administration. The Weibull distributions showed that cardiac failure occurred early after administration (early failure type), myocarditis occurred in a dose-dependent manner (wearout failure type), and myocardial infarction occurred constantly throughout the exposure period (random failure type). We focused on cardiac AEs associated with lenvatinib as post-marketing AEs. Serious outcomes can arise after lenvatinib administration. Patients should be monitored for signs of onset of these AEs not only at the start of administration, but also over an extended period.

Online condition monitoring for DC-link capacitors of three-level NPC converters using noninvasive signal injection

This paper introduces an online method for monitoring the health condition of the DC-link in three-level NPC converters. This method does not require hardware changes or modifications to the control algorithm. It involves injecting a zero-sequence signal, added to the system reference voltages to generate a neutral-point current injection. A square waveform with an interharmonic cycle frequency is used for the signal injection to minimize estimation errors caused by existing signals. This combined signal allows for the simultaneous estimation of the capacitor equivalent series resistance (ESR) and capacitance (C) at different frequency components using wavelet decomposition. Additionally, a balance between the magnitudes of the system reference voltage and the signal injection is established to prevent power quality issues. Besides, the capacitor parameters are estimated in the time-frequency domain, enabling tracking of capacitor degradation and wear-out failure. A comparison with a Fourier-based approach shows that this method provides highly accurate capacitor parameter estimation with less than 2% errors, instilling confidence in its results. Experimental results from a three-level NPC converter’s laboratory setup demonstrate the proposed method’s effectiveness.

Numerical and experimental research on the hydro-electromagnetic levitation micropump

Micropump is the core component of the microfluidic systems. However, most mechanical micropumps are using the traditional contact bearings that are troubled by wear-out failure. Hydraulic levitation, which can make the rotating components levitate without any solid-solid contact, provides efficient solution to this long-standing challenge. Nevertheless, the current hydraulic levitation technology must utilize micron microgroove structure to produce thrust forces, therefore enlarging the assemble difficulty and manufacture cost. Alternatively, a novel kind of hydro-electromagnetic levitation micropump (HELP) without grooved thrust bearing is designed in this study. Taking advantage of the coupling behavior between the electromagnetic force and hydraulic force, the rotor of the HELP can levitate in the working fluid in all directions. Thereafter, the mechanisms of levitation forces formation are elucidated by the simulations of fluid flow and motor. Results indicate that the levitation bearing can provide sufficient load capacity in all working conditions, especially in high speeds. Based on the hydro-electromagnetic levitation principle, the HELP prototype is manufactured, whose overall size is as large as a coin, but can output the hydraulic performance of over 3160 mL/min and 90.5 kPa at 20000 RPM, which is several times over other micropumps. To verify the rotor levitation performance, the levitation trajectory test benches are built on the basis of laser displacement sensors. Results prove that the designed HELP can levitate stably in all directions at all rotational speeds. The proposed levitation micropump may be an excellent choice for powering the liquid cooling systems with high performance and high reliability.

Statistical Reliability Estimation of Deep Space Satellites and Launch Vehicles: 1958–2022

On-orbit flight data for deep space satellites and space launch vehicles (SLVs) servicing deep space missions operated between 1958 and 2022 is analyzed due to a lack of reliability research combining both satellites and SLVs for this class of mission. Satellite reliability is first estimated by the Kaplan–Meier estimator, and then parameterized through the Weibull distribution. This process is applied to the general deep space satellite data set as well as the delimitation of the data according to decade. SLV reliability is computed using standard maximum likelihood estimation and an evolving first-level Bayesian estimation scheme. Results from the satellite analysis demonstrated the differences between the parameterization methods used. The bulk satellite data set indicated that deep space satellites suffer from infant mortality, while certain subsets were found to have a primary wear-out failure mode. In general, U.S. deep space missions demonstrated the highest reliability. Deep space satellite reliability was also found to have increased as a function of time. Results from the SLV data set revealed that deep space launches are primarily performed by four main launch vehicle families. Additionally, most deep space SLV failures occurred in the space age (1959–1975), with the USA and USSR/Russia being the only two countries to experience deep space launch failures. With both deep space SLV and satellite reliability increasing over time, reliability is not expected to be a major hindrance to future deep space missions.

Emergent lifetime distribution from complex network systems aging

Most theoretical analysis for lifetime distribution explains origins of specific distribution based on independent failure. We develop one unified framework encompassing different kinds of lifetime distribution for failure coupling system. For typical complex networks, we found that three types of system lifetime distributions are emerged shaped by system size and failure coupling strength. When the failure coupling strength ϕ dominates, systems exhibit a cascade failure mode, the system lifetime following an exponential distribution as series systems due to long-range correlation. When the system size N dominates, systems exhibit wear-out failure mode, the system lifetime following the Gompertz model as parallel systems due to short-range correlation. When N and ϕ have comparable impact on systems, system lifetime follows a modified Weibull distribution. We find the critical failure coupling strength and critical system size which are helpful to identify the failure mode switch point. We provide rigorous theoretical analysis for emerged lifetime distribution. We reveal the microscopic mechanism of system lifetime distribution switch pattern by analyzing the competence between correlation length and network diameter. Finally, we verify our conclusions in real networks. Our study will help to understand the lifetime origin of complex systems and design highly reliable systems.

A Method for Separation of Power Semiconductor Packaging-Related Wear-Out Mechanisms Under Converter Operation

This paper proposes a new method to separate the package-related wear-out failure mechanisms of wire-bonded silicon-based power semiconductor switches: bond-wires lift-off and solder layer degradation. The proposed method takes the on-state voltages of power semiconductor device during the start-up transient and steady-state of power converters only, respectively, to realize the separation. It overcomes the challenges faced by existing separation methods that have complex off-line implementation process or are applicable to the devices with specific bond-wires connection and operational characteristic. The proposed method has the features of easy-of-implementation, on-line implementation, and relatively general application compared to existing methods. A case study with a single-phase inverter is demonstrated to prove the effectiveness of the proposed method.

Pituitary-Related Adverse Events and Onset Patterns Caused by Immune Checkpoint Inhibitors: Analysis Using the Japanese Adverse Drug Event Report Database.

Background and Objectives: One type of immune-related adverse event caused by immune checkpoint inhibitors (ICIs) is pituitary-related adverse events. The management of pituitary-related adverse events is important because they can be fatal if not treated promptly. Therefore, this study was conducted to investigate the onset of pituitary-related adverse events using the Japanese Adverse Drug Report (JADER) database. Materials and Methods: Cases registered in the JADER database from 2004 to 2019 were used. The target drugs were ipilimumab, nivolumab, pembrolizumab, avelumab, atezolizumab, and durvalumab, and the target adverse events were the high-level terms "Anterior pituitary hypofunction," "Anterior pituitary hyperfunction," "Posterior pituitary disorder," and "Pituitary neoplasm" in the Medical Dictionary for Regulatory Activities, Japanese version (MedDRA/J). The information component (IC) was used for signal detection and IC delta (ICΔ) was used for women-related signals. Onset timing and patterns were analyzed using the Weibull distribution. Results: Signals were detected with ipilimumab, nivolumab, pembrolizumab, and atezolizumab in "Anterior pituitary hypofunction," with ICs and 95% credible intervals (95%CrI) of 5.53 (5.30-5.69), 4.96 (4.79-5.08), 4.04 (3.76-4.25), and 2.40 (1.53-3.00). Significant signals were detected in women, except for atezolizumab. Additionally, the time of onset was classified as the wear-out failure type. Inverse signals were detected with ipilimumab and nivolumab in "Posterior pituitary disorder," with ICs (95%CrI) of -1.24 (-2.80--0.26), and -0.89 (-1.64--0.37). Conclusions: Anterior pituitary hypofunction is likely to occur with the long-term administration of ipilimumab, nivolumab, and pembrolizumab. Further investigation is needed to determine the differences in the tendencies to detect signals in the anterior and posterior pituitaries between ipilimumab and nivolumab.

Analyze periodic inspection and replacement policy of a shock and wear model with phase-type inter-shock arrival times using roots method

We consider a shock and wear model in which the inter-shock arrival process is a phase-type (PH) renewal process, and the system’s lifetime is generally distributed. The system has two competing failure modes. One failure mode is due to random shocks, which cause failure by overloading the system. The other failure mode is owning to wear-out failures, which usually happen after the system has run for many cycles. System failure is not self-announcing and remains undiscovered unless an inspection is performed. The intervals between successive inspections are identical and equal to T time units. If a system failure is detected, the corrective repair or replacement is conducted immediately. If the system is found working at inspection, preventive maintenance will be carried out to prolong its useful life. Furthermore, to model the occurrence of events with an underlying monotonic trend, the extended geometric process (EGP) is employed to account for the impact of different types of failures on the system’s degradation. Moreover, for establishing the cost rate function in our model, the counting process generated from a PH renewal shock process is studied in detail using the roots method and formula for calculating residues. Based on these results, the survival function and other characteristics of the system are further investigated. Finally, numerical examples that determine the optimal inspection period T[Formula: see text] and the optimal replacement policy N[Formula: see text], which minimizes the long-run average cost rate, are presented.

복합 고장 유형을 가지는 변압기에 대한 수명추정

Purpose: Because transformers are the primary component for the delivery of electric power, failures but also small irregularities can lead to expensive damage. Wear-out failure, in particular, can be minimized using lifetime analysis. This study focuses on the lifetime estimation of transformers and considers multiple failure-modes. In this way, the reliability of aging equipment can be analyzed individually.BRMethods: We propose a change-point model for the Weibull distribution for multiple failure-modes. By defining the function for a generalized likelihood ratio, the change-point for wear-out failure as well as the parameters for multiple lifetime-distributions can be estimated.BRResults: The proposed approach is applied to real-life data of electric transformers. As a result of the lifetime analysis, the lifetime distribution, including multiple failure-modes and their cutoff points (in time) can be determined.BRConclusion: Using the investigated change-point analysis, both the lifetime and maintenance schedule of transformers with respect to multiple failure-modes can be estimated, and the chance for expensive equipment failure is reduced significantly.

Experimental studies on shape and size effects on particle breakage of railway ballast

Particle breakage, which contributes to ballast bed deforms and degradation, highly affect the performance of the railway track. Experimental studies on particle breakage of ballast are difficult, not only due to the large size and high strength of the material, but also because of complex shape and size effects. In this study, these effects on the particle breakage of ballast are investigated, by a self-designed trapezoidal groove device for single particles and an impact loading device for uniform aggregate. The results show as follows. (1) Single ballast particle is broken as a brittle shear failure, with penetrating cracks and small particles. The more uniform the contact positions are, the less likely shear failure happens. (2) Under the impact energy of 26.8 kJ, the mass loss of flaky particles and elongated particles can exceed 40 %, mainly by fracture breakage; yet that of cube particles is less than 4 %, mainly by wear-out failure. (3) The particle breakage index Bg could be a reasonable index describing the breakage evolution. (4) There is a critical particle size where the ballast takes the highest energy per volume to break. (5) There are three stages in the volumetric change: void filling, skeleton failure, and final stabilization.

Association between seasonal influenza vaccines and the increased risk of acute disseminated encephalomyelitis, estimated using the Vaccine Adverse Event Reporting System.

Acute disseminated encephalomyelitis (ADEM) is a rare and immune-mediated inflammatory disorder of the central nervous system (CNS) that can be triggered by infections and vaccinations. To date, only anecdotal case studies have reported the association between ADEM incidence and seasonal influenza vaccines, and multiple studies have found no association. This study aimed to investigate the association between the incidence of ADEM and seasonal influenza vaccines in a real-world setting using data from the United States Vaccine Adverse Event Reporting System (VAERS). Further, propensity score matching and disproportionality analysis was performed by calculating the adjusted reporting odds ratio (ROR) of reported ADEM cases associated with seasonal influenza vaccines using multiple logistic regression. Additionally, we analysed the time-to-onset using Weibull shape parameters (WSPs). The VAERS database contained 390,352 adverse events reported from January 2011 to December 2020. The ROR of seasonal influenza vaccines for ADEM was 3.02 (95% confidence interval: 1.72-5.33). The median duration (interquartile range) of ADEM was 11.0 (5.0-33.0) days. The median duration of ADEM induced by egg culture-based influenza vaccine (Egg-based vaccine) and cell culture-based influenza vaccine (Cell-based vaccine) was 10.0 (5.0-24.0) and 91.0 (79.0-125.0) days (P < 0.001), respectively. Only Cell-based cases had WSP β > 1, indicating a wear-out failure type. The incidence of ADEM within 30 days after administration of egg- and Cell-based vaccines was 78.6% and 0.0%, respectively. Our findings indicate that ADEM incidence is associated with seasonal influenza vaccines; thus, careful monitoring of ADEM is required within the first month of Egg-based vaccination and after two months of Cell-based vaccination. Neurologists and general practitioners should exercise caution, as the timing for careful monitoring varies depending on the vaccine type.

Analysis of adverse drug events in pulmonary Mycobacterium avium complex disease using spontaneous reporting system

BackgroundIn Japan, Mycobacterium avium complex lung disease (MAC-LD) is the most common in nontuberculous mycobacterial lung disease. Patients often experience adverse events, resulting in the discontinuation of treatment, which causes treatment failure. The JADER (Japanese Adverse Drug Event Report) database is a database of adverse events that allows us to collect real-world data on adverse events. We can collect large-scale data cost-effectively and detect signals of potential adverse events such as reporting odds ratio (ROR) by using spontaneous reporting systems. In this study, we aimed to elucidate the adverse events of clarithromycin (CAM), ethambutol (EB), and rifampicin (RFP) using the JADER database.MethodsWe included cases of MAC-LD between April 2004 and June 2017. We investigated sex, age, and medications that may have caused the adverse events, outcomes, and time of onset. We calculated the safety signal index as the ROR. Time-to-event analysis was performed using the Weibull distribution.ResultsThe total number of adverse events of CAM, EB, and RFP was 2780, with 806 patients. In the overall adverse events, hematologic and lymphatic disorders were the most common adverse events, with 17.3%, followed by eye disorders (16.6%), and hepatobiliary disorders (14.0%). The outcomes were as follows: recovery, 40.0%; remission, 27.1%; non-recovery, 11.2%; and death, 7.1%. Regarding the most common onset time of CAM, EB, and RFP was within 120 days at 40%, 181–300 days at 43.6%, and within 120 days at 88.5%. For CAM, the RORs of infections and infestations, hepatobiliary system disorders, and immune system disorders were 4.13 (95% confidence interval [CI], 2.3–7.44), 2.61 (95% CI, 1.39–4.91), and 2.38 (95% CI, 1.04–5.44). For EB, the ROR of eye disorders was 215.79 (95% CI, 132.62–351.12). For RFP, the RORs of renal and urinary tract disorders and investigations were 7.03 (95% CI, 3.35–14.77) and 6.99 (95% CI, 3.22–15.18). The β value of EB was 2.07 (95% CI, 1.48–2.76), which was classified as a wear-out failure type.ConclusionsFor MAC-LD, the adverse event which has the highest ROR is infections and infestations in CAM, eye disorders in EB, renal and urinary tract disorders in RFP. Adverse events of EB occur after 180 days, whereas the adverse events of CAM and RFP occur early in the course of treatment.

Periodic maintenance optimization considering the difference of preventive maintenance effect based on generalized Polya process

Previous studies seldom consider the difference of preventive maintenance effect on different failure processes when establishing the preventive maintenance model. Meanwhile, preventive maintenance models usually assume that minimal repair is performed for each failure, but this assumption is not applicable in some systems. Once this assumption is made for the inapplicable system, the maintenance strategy obtained by the established preventive maintenance model will not be optimal. In order to get a better maintenance policy to reduce maintenance cost, this paper divides the system failure processes into two types: wear-out type and damage-type. The model assumes that preventive maintenance can reduce the probability of damage-type failure, but it has no effect on wear-out type failure. At the same time, for the system studied in this paper, it is assumed that after corrective maintenance, the overall state of the system is worse than the moment just prior to the failure. Then, an extended preventive maintenance optimization model based on generalized Polya process is established. Finally, a practical algorithm is designed to solve the model. The analysis of numerical examples shows the potential value of the proposed method, which may provide maintenance guidance for enterprises and save maintenance costs.

Third-Harmonic Current Injection for Wear-Out Reduction in Single-Phase PV Inverters

The expansion of grid-connected photovoltaic (PV) systems over the years has been followed by concerns about the PV inverter reliability. It is well known that single-phase grid-connected PV inverter has a double-line frequency ripple in the dc-link voltage, which increases the wear-out failure probability of the dc-link capacitor and affects the overall inverter reliability. This work uses a third-harmonic current injection to attenuate the double-line frequency ripple in the dc-link capacitor voltage and to improve the PV system reliability. An analytical model capable to describe the effects of the third-harmonic current injection method in the dc-link capacitor is derived. The proposed strategy is validated by simulation and experimental results. The lifetime evaluation is developed considering a 3 kVA PV inverter and one-year mission profiles. The PV inverter failure probability considering an operation period equal to 20 years decreased in 27.17% for the adopted case study. Moreover, this strategy provides a straightforward retrofit of the current inverter technology, requiring no hardwarechanges.

Reliability analysis of battery energy storage system for various stationary applications

This paper provides a comparative study of the battery energy storage system (BESS) reliability considering the wear-out and random failure mechanisms in the power electronic converter long with the calendar and cycling aging of the batteries. Three typical stationary applications were considered: frequency containment reserve (FCR), increased self-consumption (ISC) in the case of residential photovoltaic (PV) applications, and peak shaving (PS) in the industrial sector. The mission profile of these applications (e.g., the BESS state-of-charge (SOC) and power) is much different, resulting in the different distribution in the accumulated damage of power electronics components. The random failure analysis based on the MIL-HDBK-217 and wear-out failure rates is carried out for the component and converter levels in each operating regime using the mathematical models. The analysis results revealed that the most prone component in the BESS converter is the dc-link capacitor, where the B10 lifetime of the BESS converter is 24, 13, and 15 years for the FCR, ISC, and PS applications, respectively. Moreover, the results show that the capacity fading in the PS applications is much higher than that of the FCR and ISC. In contrast, the capacity fading due to the cycling effect in both the FCR and ISC is dominant.

Parameters Estimation for Wear-out Failure Period of Three-Parameter Weibull Distribution

The shape parameter estimation using the minimum-variance linear estimator with hyperparameter (MVLE-H) method is believed to be effective for a wear-out failure period in a small sample. In the process of the estimation, our method uses the hyperparameter and estimate shape parameters of the MVLE-H method. To obtain the optimal hyperparameter c, it takes a long time, even in the case of the small sample. The main purpose of this paper is to remove the restriction of small samples. We observed that if we set the shape parameters, for sample size n and c, we can use the regression equation to infer the optimal c from n. So we searched in five increments and complemented the hyperparameter for the remaining sample sizes with a linear regression line. We used Monte Carlo simulations (MCSs) to determine the optimal hyperparameter for various sample sizes and shape parameters of the MVLE-H method. Intrinsically, we showed that the MVLE-H method performs well by determining the hyperparameter. Further, we showed that the location and scale parameter estimations are improved using the shape parameter estimated by the MVLE-H method. We verified the validity of the MVLE-H method using MCSs and a numerical example.

Wear-out failure analysis of modular multilevel converter-based STATCOM: The role of the modulation strategy and IGBT blocking voltage

The modular multilevel converter (MMC) is an attractive option for medium- and high-voltage static synchronous compensator (STATCOM) application. For this application, three aspects are relevant. Firstly, reliability and efficiency are directly related to the operation costs of this converter. Secondly, either high IGBT blocking voltage capability, featuring few number of submodules (SMs), or low-voltage IGBT modules, with a larger number of SMs, can be employed in an MMC-STATCOM. Lastly, either modulation strategies with fixed or variable switching frequency can be employed. Nevertheless, the literature does not present works evaluating these three aspects of an MMC-STATCOM at the same time. Therefore, this paper analyzes the impact of modulation strategies and number of SMs on wear-out failure and efficiency of an MMC-STATCOM. The effect of all SM components is considered. Two distinct modulation strategies are selected: phase-shifted pulse-width modulation (PS-PWM), with fixed switching frequency, and nearest-level control with cell tolerance band algorithm (NLC-CTB), with variable switching frequency. Four commercially available semiconductor blocking voltages are considered to evaluate the converter with different number of SMs. The results demonstrate that the number of SMs and the modulation strategy affect the MMC-STATCOM performance. Indeed, the converter presents different reliability at system-level and energy losses per year, depending on the IGBT blocking voltage and modulation strategy. The design with higher IGBT blocking voltage is the most affected.

Reliability of vertical-cavity surface-emitting laser arrays with redundancy

This paper describes theoretical reliability analysis of a system containing n optical ports in which each optical port contains m redundant vertical-cavity surface-emitting lasers. We study the wearout failure statistics, modelled with lognormal distribution, for three different chip-level integration approaches: ( A ) each laser on its own chip, resulting in m·n chips, ( B ) m redundant lasers associated with one channel are on a single chip, resulting in n chips, and ( C ) all m·n lasers integrated on a single chip. We present a model that includes the run-to-run reliability parameter fluctuation and find that the three integration schemes consistently exhibit MTTF( C ) ≥ MTTF( A ) ≥ MTTF( B ) for lognormal distribution shape parameters observed in commercial vertical-cavity surface-emitting lasers. We also provide analytic approximations for the failure statistics for all three integration approaches enabling straightforward calculation of the failure statistics for any redundancy and channel number.

Condition monitoring of IGBT modules using online TSEPs and data‐driven approach

The nonlinear operating characteristics associated with the power electronic converters result in high mechanical and thermal stresses for the power modules. These stresses collectively result in failure modes such as wear-out and sudden failures, which lead to power loss for the system. To overcome these aspects, this paper proposes a condition monitoring approach based on data-driven methods for power modules. The proposed approach is aimed at achieving early detection of power module failure mode by measuring the temperature sensitive electrical parameters (TSEPS) with a measurement and monitoring unit (MMU). To develop the proposed monitoring approach, 12 different online TSEPs of insulated gate bipolar transistor (IGBT) power module are measured with the MMU and trained with a support vector data descriptor classifier. The training process is carried out with a two-chip half bridge IGBT leg which is further operated in a single-phase full bridge inverter configuration during the testing process. Both the training and testing processes of the developed classifier are carried out for IGBT operation at multiple temperatures, and multiple faults to identify the repeatability of the TSEPs. The results of numerical simulations and experimental analysis identified 96.3% training accuracy and 2.9% error in testing accuracy at 90°C junction temperature for degradation identification. For the failure mode classification, the training accuracy is identified to be 98.6%, and 100% testing accuracy at 25°C.

Reliability and Failure Mode in Solid Tantalum Capacitors

The reliability and failure modes in surface mount Solid Electrolytic and Polymer Tantalum capacitors were investigated using the parts manufactured with conventional technology and flawless technology (F-Tech) that suppresses typical defects such as crystalline inclusions in the amorphous matrix of the tantalum oxide dielectric. The accelerated tests were performed; failure rates were calculated based on the cumulative percent of failed parts vs time and acceleration factor. Scanning electron microscopy (SEM), energy dispersive X-ray (EDX) spectroscopy and thermo-gravimetric/deferential scanning calorimetry analysis (TGA/DSC) were included in the investigation to analyze chemical and structural transformations in the capacitors failed in the accelerated tests. Results show strong impact of technology on reliability and failure mode including the lowest failure rate and no wear-out failure mode in Polymer Tantalum capacitors manufactured with F-Tech. No ignition and burning tantalum were found in the Solid Electrolytic Tantalum capacitors that failed short. Limiting temperatures and protecting the encapsulating epoxy compound from ignition and burning at normal conditions of the accelerated testing take place via ablation process—heat consuming irreversible structural and chemical transformations in the material such as carbonization process.