scholarly journals Methodology for Determining Time-Dependent Lead Battery Failure Rates from Field Data

Batteries ◽  
2021 ◽  
Vol 7 (2) ◽  
pp. 39
Author(s):  
Rafael Conradt ◽  
Frederic Heidinger ◽  
Kai Peter Birke
Keyword(s):  
Power Supply ◽  
Failure Modes ◽  
Time Dependent ◽  
Failure Rates ◽  
Reliability Models ◽  
Safety Critical ◽  
Lead Battery ◽  
Reliable Power Supply ◽  
The Individual ◽  
Dependent Failure

The safety requirements in vehicles continuously increase due to more automated functions using electronic components. Besides the reliability of the components themselves, a reliable power supply is crucial for a safe overall system. Different architectures for a safe power supply consider the lead battery as a backup solution for safety-critical applications. Various ageing mechanisms influence the performance of the battery and have an impact on its reliability. In order to qualify the battery with its specific failure modes for use in safety-critical applications, it is necessary to prove this reliability by failure rates. Previous investigations determine the fixed failure rates of lead batteries using data from teardown analyses to identify the battery failure modes but did not include the lifetime of these batteries examined. Alternatively, lifetime values of battery replacements in workshops without knowing the reason for failure were used to determine the overall time-dependent failure rate. This study presents a method for determining reliability models of lead batteries by investigating individual failure modes. Since batteries are subject to ageing, the analysis of lifetime values of different failure modes results in time-dependent failure rates of different magnitudes. The failure rates of the individual failure modes develop with different shapes over time, which allows their ageing behaviour to be evaluated.

The Integrative Time-Dependent Modeling of the Reliability and Failure of the Causes of Drivers' Error Leading to Road Accidents

2015 ◽  
pp. 1279-1294
Author(s):  
Khashayar Hojjati-Emami ◽  
Balbir S. Dhillon ◽  
Kouroush Jenab
Keyword(s):  
Human Error ◽  
Time Dependent ◽  
Failure Rates ◽  
Road Accidents ◽  
Road Transportation ◽  
The Road ◽  
Representational Model ◽  
On The Road ◽  
The Moment ◽  
Dependent Failure

Nowadays, the human error is usually identified as the conclusive cause of investigations in road accidents. The human although is the person in control of vehicle until the moment of crash but it has to be understood that the human is under continued impact by various factors including road environment, vehicle and human's state, abilities and conduct. The current advances in design of vehicle and roads have been intended to provide drivers with extra comfort with less physical and mental efforts, whereas the fatigue imposed on driver is just being transformed from over-load fatigue to under-load fatigue and boredom. A representational model to illustrate the relationships between design and condition of vehicle and road as well as driver's condition and state on fatigue and the human error leading to accidents has been developed. Thereafter, the stochastic mathematical models based on time-dependent failure rates were developed to make prediction on the road transportation reliability and failure probabilities due to each cause (vehicle, road environment, human due to fatigue, and human due to non fatigue factors). Furthermore, the supportive assessment methodology and models to assess and predict the failure rates of driver due to each category of causes were developed and proposed.

A New Probabilistic Approach for Accurate Fatigue Data Analysis of Ceramic Materials

1999 ◽  
Author(s):  
Bjoern Schenk ◽  
Peggy J. Brehm ◽  
M. N. Menon ◽  
William T. Tucker ◽  
Alonso D. Peralta
Keyword(s):  
Data Analysis ◽  
Failure Modes ◽  
Probabilistic Approach ◽  
Time Dependent ◽  
Material Strength ◽  
Static Fatigue ◽  
Oak Ridge ◽  
Fatigue Data ◽  
Ceramic Components ◽  
Dependent Failure

Statistical methods for the design of ceramic components for time-dependent failure modes have been developed which can significantly enhance component reliability, reduce baseline data generation costs, and lead to more accurate estimates of slow crack growth (SCG) parameters. These methods are incorporated into the AlliedSignal Engines CERAMIC and ERICA computer codes. Use of the codes facilitates generation of material strength parameters and SCG parameters simultaneously, by pooling fast fracture data from specimens that are of different sizes, or stressed by different loading conditions, with data derived from static fatigue experiments. The codes also include approaches to calculation of confidence bounds for the Weibull and SCG parameters of censored data and for the predicted reliability of ceramic components. This paper presents a summary of this new fatigue data analysis technique and an example demonstrating the capabilities of the codes with respect to time-dependent failure modes. This work was sponsored by the U.S. Department of Energy Oak Ridge National Laboratory (DoE/ORNL) under Contract No. DE-AC05-84OR21400.

The Integrative Time-Dependent Modeling of the Reliability and Failure of the Causes of Drivers’ Error Leading to Road Accidents

2013 ◽  
Vol 4 (1) ◽  
pp. 25-39 ◽  
Author(s):  
Khashayar Hojjati-Emami ◽  
Balbir S. Dhillon ◽  
Kouroush Jenab
Keyword(s):  
Human Error ◽  
Time Dependent ◽  
Failure Rates ◽  
Road Accidents ◽  
Road Transportation ◽  
The Road ◽  
Representational Model ◽  
On The Road ◽  
The Moment ◽  
Dependent Failure

Nowadays, the human error is usually identified as the conclusive cause of investigations in road accidents. The human although is the person in control of vehicle until the moment of crash but it has to be understood that the human is under continued impact by various factors including road environment, vehicle and human’s state, abilities and conduct. The current advances in design of vehicle and roads have been intended to provide drivers with extra comfort with less physical and mental efforts, whereas the fatigue imposed on driver is just being transformed from over-load fatigue to under-load fatigue and boredom. A representational model to illustrate the relationships between design and condition of vehicle and road as well as driver’s condition and state on fatigue and the human error leading to accidents has been developed. Thereafter, the stochastic mathematical models based on time-dependent failure rates were developed to make prediction on the road transportation reliability and failure probabilities due to each cause (vehicle, road environment, human due to fatigue, and human due to non fatigue factors). Furthermore, the supportive assessment methodology and models to assess and predict the failure rates of driver due to each category of causes were developed and proposed.

A Time Dependent Model for Assessing the Significance of Mechanical Damage

2006 ◽  
Author(s):  
Michael Martin ◽  
Robert (Bob) Andrews
Keyword(s):  
Failure Modes ◽  
Mechanical Damage ◽  
Time Dependent ◽  
External Interference ◽  
Complex Load ◽  
Final Failure ◽  
Dependent Model ◽  
Dependent Failure ◽  
Pipeline Failures ◽  
Type Of Failure

A small but significant number of pipeline failures occur each year and many in populated regions arise as a result of mechanical damage from external interference. These failures generally occur at the time of damage, but a small number are delayed, with the final failure reportedly taking place following periods of up to 40 years from the original damage. This type of failure is of concern to pipeline operators as they occur without warning. The mechanisms governing time-delayed failures are poorly understood due to the extremely limited experimental data available. A greater understanding of the failure mechanism would help operators to improve their strategies for managing external interference damage. In the event of combined dent and gouge mechanical damage, the model described in this paper provides an approach for the assessment of the time dependent failure modes of the defective pipeline. The model, developed using Matlab code, is capable of investigating a complex load history consisting of constant internal pressure hold periods and cyclic fluctuations and can predict time dependent phenomenon such as pressure reversals sometimes experienced following hydrostatic pressure testing. The approach is based on the BS 7910 material specific Failure Assessment Diagram (FAD) in conjunction with R5 (British Energy) creep procedures. The result is a time dependent FAD which allows the combined influence of time dependent material properties (toughness, strength and cold creep) and loading to be investigated.

Safety Assessment of Pressure Vessels in Service for More Than 20 Years

2020 ◽  
Author(s):  
Chen Xuedong ◽  
Fan Zhichao ◽  
Dong Jie ◽  
Ai Zhibin ◽  
Hu Mingdong
Keyword(s):  
Pressure Vessel ◽  
Failure Modes ◽  
Experimental Studies ◽  
Safety Evaluation ◽  
Pressure Vessels ◽  
Time Dependent ◽  
Economic Losses ◽  
Safety Specification ◽  
Pressure Swing ◽  
Dependent Failure

Abstract In recent years, a large number of pressure vessels for the petrochemical plants built in China in the 20th century have been in service for more than 20 years. The Chinese pressure vessel safety specification TSG 21-2016 “Supervision Regulation on Safety Technology for Stationary Pressure Vessel” stipulates that if the pressure vessels without definite design lives have been in service for more than 20 years, they shall be considered to have reached the design service lives. For these pressure vessels, if they are all blindly scrapped, it will cause huge economic losses. However, if they continue to be used blindly, it may bring great safety risks. In this paper, the failure mode, mechanism and damage evolution law are analyzed through a number of failure accident investigations and experimental studies, for typical pressure vessels such as large LPG spherical tanks, pressure swing adsorbers and coke drums. The classification method of pressure vessel for the time-independent and time-dependent failure modes has been proposed. As for the pressure vessels with time-independent failure modes, the principle to determine target life, and the strategy of inspection and maintenance have been proposed. While for the time-dependent failure modes, the safety evaluation and remaining life prediction methods for the pressure vessels with and without defects have been provided. Finally, the advices on amendment to the relevant regulations on pressure vessels have been proposed. The research findings could provide guidance for rationally determining the safety grades and scientifically extending the service lives of pressure vessels.

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