Reliability Analysis Of Components Research Articles

Reliability analysis of arbitrary systems based on active learning and global sensitivity analysis

System reliability analysis aims at computing the probability of failure of an engineering system given a set of uncertain inputs and limit state functions. Active-learning solution schemes have been shown to be a viable tool but as of yet they are not as efficient as in the context of component reliability analysis. This is due to some peculiarities of system problems, such as the presence of multiple failure modes and their uneven contribution to failure, or the dependence on the system configuration (e.g., series or parallel). In this work, we propose a novel active learning strategy designed for solving general system reliability problems. This algorithm combines subset simulation and Kriging/PC-Kriging, and relies on an enrichment scheme tailored to specifically address the weaknesses of this class of methods. More specifically, it relies on three components: (i) a new learning function that does not require the specification of the system configuration, (ii) a density-based clustering technique that allows one to automatically detect the different failure modes, and (iii) sensitivity analysis to estimate the contribution of each limit state to system failure so as to select only the most relevant ones for enrichment. The proposed method is validated on two analytical examples and compared against results gathered in the literature. Finally, a complex engineering problem related to power transmission is solved, thereby showcasing the efficiency of the proposed method in a real-case scenario.

Reliability Analysis and Life Cycle Cost Optimization of Hydraulic Excavator

This study focuses on conducting a reliability analysis of an excavator from its field failure data and improve its reliability cost effectively. The aim of the research is to perform reliability estimation of systems and identify the critical subsystem with significant contributions to system unreliability. The reliability analysis was performed using repairable system data analysis approaches. Life cycle cost (LCC) was estimated for critical subsystems, and it was optimized to select cost effective reliability improvement strategy. The results of the study provide valuable insights into the performance and cost-effectiveness of the excavator and its subsystems, which can assist manufacturers and operators in optimizing their equipment’s reliability, availability while considering the cost implications over the life cycle of the equipment. The results show that the undercarriage has critical contributions to system unreliability. This study attempts deep down reliability analysis of critical undercarriage components for optimal selection of improvement method among feasible alternatives. LCC analysis and its optimization performed on the critical sub-system is expected to help OEM save approx. 15% of LCC. The empirical data used in the paper is based on field data gathered during the operational life of the hydraulic excavator over approx. six years in its Indian operations.

Notch structural stress theory: Part II predicting total fatigue lives of notched structures

Notch fatigue problems are among the most common topics for the reliability analysis and structural design of mechanical engineering components. In previous work, we proposed the Notch Structural Stress (NSS) method based on fracture mechanics for reflecting the notch effect on fatigue crack propagation lives. However, like other regular fatigue assessing procedures, NSS also cannot accurately predict the fatigue life of notched structures with slower stress gradients due to the inconsistent slope of their S-N curves. This paper presents the Theory of Notch Structural Stress (TNSS) for predicting total fatigue lives of notched structures, which overcomes the life prediction limitations caused by slope differences in S-N curves and constructs a life-predicting frame suitable for different notch types even including plain and sharp notches. Compared with the often-used stress-concentration-assessing procedures, TNSS provides a more effective consolidation of the S-N data from different notch types, mostly since it takes both Initiation and Propagation state resistance into account at the same time.

The implementation of soundscape attributes in Indonesian: A case study of soundwalk

The ISO 12913-3 method A of part 2 is a standardized method to calculate the score of pleasantness and eventfulness according to the rating of standard soundscape attributes mentioned in ISO 12913-2. However, implementing the attributes might result in invalid measurement if the attributes are used directly for soundscape studies in non-English speaking countries. The Soundscape Attributes Translation Project (SATP) is an initiation to develop the standard soundscape attributes in different languages. This study employs a soundwalk to validate soundscape attributes in Indonesian and English for soundscape study in Indonesia. The validation process involves the utilization of Principal Component Analysis (PCA), Multidimensional Scaling (MDS), Reliability Analysis, and Confirmatory Factor Analysis (CFA). The analysis shows that implementing soundscape attributes in Indonesian gives a more similar result to the standard circumplex model than the standard attributes in English. Further analysis of the soundwalk data shows that the circumplex model, which implemented Indonesian attributes, is not ideal. As a result, the circumplex model might need correction. The model developed using CFA from the soundwalk experiment with Indonesian attributes demonstrates that the application of the CFA model results in average differences in pleasantness score of −1.76 and eventfulness score of −0.06 compared to the result from standard ISO 12913-3 model calculation.

Could You Evaluate Sounds in a Virtual Environment? Evaluation Components of Auditory Experience in a Metaverse Environment

The study aims to develop an auditory experience evaluation questionnaire to improve metaverse environments’ presence and derive evaluation components considering the acoustic and auditory user experience (AUX) through a survey. After conducting a survey with a total of 232 participants, five evaluation components were extracted from auditory presence and AUX evaluation factors through principal component analysis (PCA) and reliability analysis (RA): ‘realistic auditory background’, ‘acoustic aesthetics’, ‘consideration of acoustic control and accessibility’, ‘auditory utility and minimalist design’, and ‘auditory consistency’. In particular, although AUX evaluation factors such as ‘ease of access to sound control’ have limitations in improving the sense of presence, negative factors of presence such as ‘distraction due to sound’ can be improved by utilizing AUX evaluation factors, so it is judged that the sense of presence in the metaverse environments can be improved by enhancing the auditory sense of presence and AUX evaluation factors according to the composition of the five evaluation components derived in the study. The study can be used as a basis for developing an auditory experience evaluation questionnaire for the metaverse platform, creating sound design guidelines, and identifying sound development priorities.

Bayesian model averaging for probabilistic S-N curves with probability distribution model form uncertainty

Reliability analysis of engineering components or structures heavily relies on accurately estimating the fatigue properties of materials. However, significant uncertainty exists regarding the distribution form and value in fatigue data, posing significant challenges in constructing a robust probability fatigue model. To address this challenge, we propose a Bayesian model averaging (BMA) method to incorporate model form uncertainty into the estimation of the probability density of fatigue life. The performance of BMA was verified through numerical experiments using both simulated and experimental data. The results highlight the robustness and reliability of BMA compared to individual models, as it effectively incorporates model form uncertainty. The proposed BMA model offers a general framework for developing probabilistic fatigue models with high robustness and accuracy in their predictions. This model contributes to advancing the field of reliability analysis by addressing the challenges posed by uncertainty and enhancing the understanding of fatigue properties for engineering components and structures.

Statistical analysis of push and pull factors of migration: A case study of India

The migration from India with special reference to Bihar has a long history. Slaves from this area were sent to British colonies like Fiji, Mauritius, Guyana, and Suriname as Girmitiya during the British colonial period. During the early years of independent India, many people from this area moved to Calcutta and Assam, Later, in the aftermath of the green revolution, people relocated to the Punjab, Haryana, and the northern states in search of financial prosperity. In the new globalized world, people are either moving to cities like Maharashtra, Gujarat, Kolkata, and Chennai, or to countries in the Gulf. Therefore, it becomes necessary to examine the major cause of migration from the research area towards the Gulf countries. The examination was quantitative and based on samples survey approach. To examine the objective and test the hypothesis, descriptive statistics, Principal component analysis, reliability analysis, and regression analysis were utilized. The study confirms that the push factor plays a significant role in people migrating. The major cause of migration was ‘lack of jobs’, ‘low wages’, ‘poor financial condition’, ‘debt. on the family’, ‘social insecurity’, & ‘social discrimination. Apart from the push factor, a few pull factors such as ‘better employment opportunities’, ‘improved living standard’, ‘personal development’, ‘presence of relatives’ & ‘attractive environment’ also plays a significant role in Gulf migration. The further result reveals that 41% of the migrants moved mainly by push factors, 6% by only push factors, 23% mainly by pull factors, 3% by only pull factors and 27% have chosen both factors as the cause of migration. The study also found that the marital status, age, family type, and religion of migrant workers are significant positive determinants of the length of their stay. On the other hand, the level of education and pre-migration income of migrant workers are significant negative determinants of the length of their stay.

System reliability analysis for independent and nonidentical components based on survival signature

Survival signatures have been widely used for analyzing arbitrary system structures having independent failure events. It is challenging to study system reliability when diverse components are present since the fundamental premise of the survival signatures is that components should be interchangeable within the same subsystem. In this research, two methods based on the fundamental survival signature idea are suggested to examine the reliability of complex systems with independently but not necessarily identically distributed (INID) components. The first algorithm is based on the weighted random sampling (WRS) method to calculate the survival signatures. The second algorithm adopts the idea of divide-and-conquer in computing the probability structure. The application of these two algorithms and the exhaustive algorithm in analyzing the example systems are presented. The results show that the two algorithms can significantly reduce the computation time compared to the traditional methods. Finally, the developed algorithms are used in the reliability analysis of a real practical problem, the Tsinghua campus water supply pipeline system. The results regarding the predictions of system reliability as well as the component importance index are discussed.

AN APPROACH TO RELIABILITY ANALYSIS OF AIRCRAFT SYSTEMS FOR A SMALL DATASET

Data-driven predictive aircraft maintenance approach typically results in lower maintenance costs, avoiding unnecessary preventive maintenance actions and reducing unexpected failures. Information provided by a reliability analysis of aircraft components and systems can improve an existing maintenance strategy and ensure an optimal maintenance task interval. For reliability work, the exponential distribution is typically used; however, this approach requires substantial amounts of data, which often may not be generated by aviation operations. Therefore, this study proposes a method for reliability analysis given a small dataset. Real-life historical data of an aircraft operating in Nigeria validate the proposed approach and prove its applicability.

AN APPROACH TO RELIABILITY ANALYSIS OF AIRCRAFT SYSTEMS FOR A SMALL DATASET

Data-driven predictive aircraft maintenance approach typically results in lower maintenance costs, avoiding unnecessary preventive maintenance actions and reducing unexpected failures. Information provided by a reliability analysis of aircraft components and systems can improve an existing maintenance strategy and ensure an optimal maintenance task interval. For reliability work, the exponential distribution is typically used; however, this approach requires substantial amounts of data, which often may not be generated by aviation operations. Therefore, this study proposes a method for reliability analysis given a small dataset. Real-life historical data of an aircraft operating in Nigeria validate the proposed approach and prove its applicability.

New reliability model for complex systems based on stochastic processes and survival signature

For systems with complicated structures, reliability analysis based on survival signature has been carried out by modelling time-to-failure data with specific distributions. However, for highly reliable systems, only little or no failure data may be available. To enable reliability analysis without failure data, a new generalised reliability method is proposed for complex systems, based on the survival signature and using stochastic processes to model degradation. The combination of the survival signature and stochastic processes enables the proposed method to be applied to complex systems with different structures and stochastically degrading components. First, system reliability is analysed based on the survival signature and a generalised stochastic process. Then, component reliability analysis based on the generalised stochastic process is introduced using Wiener and Gamma processes. Finally, the approach presented in this paper is illustrated using two numerical examples, and the estimation results are compared with those calculated using failure time distribution functions.

Research on time-varying reliability of wind power gearbox with failure correlation

1. An Z.W., Liu B., Xu J., 2013, Dynamic reliability analysis of wind power gearbox component, Proceedings of 2013 International Conference on Quality, Reliability, Risk, Maintenance and Safety Engineering, 215-219. CrossRef Google Scholar

한국여자프로골프선수의 투어 레벨에 따른 직업만족도와 운동탈진 및 인지된 경기력의 관계

The purpose of this study is to explore the relationship between job satisfaction, exercise exhaustion, and perceived performance by tour level of Korean ladies professional golf players. The survey was conducted by 234 players who participated in the KLPGA 1st Tour(KLPGA Tour, 111 players) ‘HighOne Resort Ladies Open 2021’ and 2nd Tour(Dream Tour, 123 players) ‘KLPGA 2021 TORBIST-Phoenix CC Dream Tour 10th Tournament’. Data processing was conducted using SPSS/WIN 23.0 for frequency analysis, factor analysis, principal component analysis, reliability analysis, correlation analysis, and multiple regression analysis. In addition, a t-test was conducted to analyze the difference according th the tour level. The results are as follow: First, there was no difference between job satisfaction and perceived performance depending on the tour level. However, there was a difference in physical and mental exhaustion, a sub-factor of exercise exhaustion. Second, in both the KLPGA Tour and the Dream Tour, intrinsic satisfaction, a sub-factor of job satisfaction, negatively affected the achievement deficiency of exercise exhaustion, and positively affected the perceived performance. Meanwhile, only in the KLPGA Tour, intrinsic satisfaction had a negative effect on the no-value of exercise exhaustion. Third, both the KLPGA Tour and the Dream Tour negatively affected the perceived performance of achievement deficiency, a sub-factor of exercise exhaustion.

A comparative study of 85 hyperelastic constitutive models for both unfilled rubber and highly filled rubber nanocomposite material

Nonlinear finite element analysis is widely used for structural optimization of the design and the reliability analysis of complex elastomeric components. However, high-precision numerical results cannot be achieved without reliable strain energy functions (SEFs) of the rubber or rubber nanocomposite material. Although hyperelastic constitutive models have been studied for nearly 80 years, selecting one that accurately describes rubber's mechanical response is still a challenge. This work reviews 85 isotropic SEFs based on both the phenomenological theory and the micromechanical network theory proposed from the 1940s to 2019. A fitting algorithm which can realize the automatic fitting optimization and determination of the parameters of all SEFs reviewed is developed. The ability of each SEF to reproduce the experimental data of both the unfilled and highly filled rubber nanocomposite is quantitatively assessed based on a new proposed evaluation index. The top 30 SEFs for the unfilled rubber and the top 14 SEFs for the highly filled rubber nanocomposite are presented in the ranking lists. Finally, some suggestions on how to select an appropriate hyperelastic constitutive model are given, and the perspective on the future progress of constitutive models is summarized.

한국여자프로골프 1부투어 선수의 스트레스가 운동탈진과 직업만족도에 미치는 영향

The purpose of this study is to explore the effect of stress on exercise exhaustion and job satisfaction for Korea ladies professional golf players. A survey was conducted on all players who participated in the ‘KLPGA HighOne Resort Ladies Open 2021’ and analyzed the data of a total of 111 players. Data processing was conducted using SPSS/WIN 23.0 for frequency analysis, factor analysis principal component analysis, reliability analysis, correlation analysis, and multiple session analysis. The results are as follow: First, economic stress and family and coach stress had a positive effect on physical/mental exhaustion, lack of achievement, and valueless. However, exercise performance functional stress negatively affected valueless. Second, family and coach stress had a negative effect on job satisfaction. However, exercise performance functional stress had a positive effect on intrinsic satisfaction. Third, valueless had a negative effect on job satisfaction. In addition, lack of achievement negatively affected intrinsic satisfaction.

Component reliability and sensitivity analysis of anchor-pile-wall reinforcement design of a multilayer soil slope

Component reliability and sensitivity analysis of soil-slope combined-reinforcement deterministic designs are studied using a hybrid numerical-probabilistic method. Major components are qualitatively identified with numerical simulations to avoid redundancy evaluations. Quadratic polynomials as response surfaces are stepwise regressed to predict component load effects. Major component resistances of supporting structures are calculated in states of soil ultimate equilibrium and maximum allowable deformations obtained according to building and foundation types. Component performance functions (PFs) are established based on component failure models and soil-mass deformation properties. Reinforced slope stability reliabilities are calculated with first-order second-moment and design point methods. The reinforcement probability safety indicated by component reliability indices is adopted to check whether the deterministic design needs improvement. This methodology is applied to a loess slope reinforced by combined supporting. The resultant reliability indices of the slope imply some improving treatments should be made. Sensitivity analysis shows some variable variation has a more significant impact on the PFs; inversely signed sensitivity coefficients indicate that the equilibrium point between PFs should be considered when modifying parameters. Stable monitoring results of modified design implementation indicate that probabilistic analysis of component stability is necessary for some slope-treatment designs with distinct probability distribution variables.

Reliability Analysis of Power Components in Restructured DC/DC Converters

This paper presents a generalized restructured topology for boost, buck-boost and its derived dc/dc converters with rearranging branches to enhance the reliability of the converter. This paper instigates the derivation of state-of-the-art topologies with reduced capacitor voltage stress. Mainly in the restructured topology, the capacitor branch is rearranged in the converter and this redesign venture results in profuse advantages like a better choice of the capacitor with low voltage rating, low equivalent series resistance and reduced voltage stress of the converter. The investigation of the capacitor voltage stress and reliability test is carried out. No extra components are required in this method, the same component count as the conventional converter is maintained. In comparison with the conventional converters, the restructured topology shows the identical output voltage with decreased capacitor voltage stress. Besides reduced voltage stress, the capacitor losses are also less and this allows the capacitor to perform better. As a consequence, the efficiency and lifetime are improved and extended. A detailed illustration of the significance of this restructured concept is presented with a validating analysis. Experimental results from a 600 W prototype are presented with different duty cycles for validating and highlighting the special features of the restructured topology.

Community Pharmacists' Experiences and Perception about Transitions of Care from Hospital to Home in a Midwestern Metropolis.

Objectives: (1) To describe the experiences of community pharmacists in transitions of care (TOC) from hospital to home in a Midwestern metropolis; and (2) to develop instruments to measure perceived importance of TOC activities. Methods: Survey items were developed, including a six-item instrument to capture perceived importance of TOC activities. The items were piloted to examine face validity before dissemination to 310 community pharmacists. Descriptive statistics were reported. Principal component analysis and reliability analysis for the six-item instrument were performed to assess construct validity and Cronbach’s alpha, respectively. Results: The response rate was 37% (n = 118). The majority of community pharmacists estimated that they learned of a patient’s discharge on less than 10% of the occasions. There were 76 cases in which the discharged patients experienced either a prescription- or medication-related problem. For the six-item measurement of perceived importance, one component was yielded and all items loaded on the component with high values, which confirmed construct validity. The Cronbach’s alpha for these six items was 0.941, indicating high reliability. Conclusions: A large communication gap existed for community pharmacists to receive patient discharge information. The six-item instrument to measure perceived importance of TOC activities was valid and reliable.

Reliability Analysis for Unrepairable Automotive Components.

The analysis of the reliability parameters of a technical object and the determination of the change in the reliability of the object over time, requires the knowledge of the functional characteristics and reliability parameters of the elements included in a system. On the basis of the failure data of the selected element of the object, in this case the vehicle, it is possible to determine the average working time to failure of the element and the appropriate form of distribution that characterizes the reliability and durability parameters of the tested element. The main purpose of the research presented in the article was to develop a method of assessing the reliability of an electronic component of a vehicle-a boot lid contactor. This paper also presents three possible methods of repairing the boot lid contactor (sealing the housing with adhesive with better way, replacing the element with a new one or the most time-consuming solution, changing the shape of the boot lid). The authors also decided to determine the reliability and cost parameters that will allow preventive replacement of this element. The tests were carried out on a fleet of 61 vehicles of the same model, but with different body structures. Contactor failures were reported in 41 cases, of which 29 were in the hatchback construction and 12 in the estate type. The analysis of the distribution selection for the tested part of the passenger car-the boot lid contactor-was performed using the Likelihood Value (LKV) test to determine the rank of distributions. Also the maximum likelihood (MLE) method was used to estimate the distribution parameters. The three-parameter Weibull distribution was the best-fitted distribution in both cases. It was clearly defined that one model of car with two different types of body have vastly different reliability characteristic. Based on the reliability characteristic and parameters, the appropriate preventive actions can be taken, minimizing the risk of damage, thus avoiding financial losses and guaranteeing an appropriate level of vehicle safety.

KLPGA 3부투어 선수들이 인지하는 지도자 신뢰와 지도자 역할 및 인지된 경기력의 관계

This study aims to identify the relationship between trust of coach, role of coach and perceived performance recognized by Korea ladies semi-professional golfers. A survey was conducted on all players who participated in the ‘KLPGA 2021 XGOLF · Baekje CC Jump Tour’ and analyzed the data of a total of 123 players. Data processing was conducted using SPSS/WIN 25.0 for frequency analysis, factor analysis, principal component analysis, reliability analysis, correlation analysis and multiple session analysis. The results are as follows: First, it has been shown that intellectual trust perceived by Korea ladies semi-professional golfers has a significant impact on coaching characteristics, but it has no significant impact on coaching needs. Meanwhile, the identification trust has a significant impact on perceived performance. Second, coaching characteristics recognized by Korea ladies semi-professional golfers have a significant impact on perceived performance.