scholarly journals FTA analysis of the failure in the horizontal fluidity test

10.30544/69 ◽  
2015 ◽  
Vol 21 (4) ◽  
pp. 229-240 ◽  
Author(s):  
Peter Blaško ◽  
Jozef Petrík
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Molten Metal ◽  
Potential Risk ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Energy Potential ◽  
Tree Analysis ◽  
The Monte Carlo Method ◽  
Fluidity Test

The purpose of the paper was to evaluate the probability of the top event in the fluidity test by Fault Tree Analysis (FTA). One of the important tests used in the foundry practice is the test of the fluidity. Fluidity is the ability of the molten metal to fill the cavity of the molds and create a cast. The AlSi10MgMn (EN 1706) alloy with 5 or 10.54 % of silica was the experimental material. The melted alloy was cast into "horizontal" three-channel mold to test its fluidity. The pouring temperatures were between 605 and 830 °C. In some cases, the experiment was not successful, for a some reasons. This fact led to a waste of time, energy, potential risk of accident, confusion among participants, especially "beginners" founders and became an impulse for the analysis of creation and possible events of fault for the fluidity test using the FTA. It has been found that for the probability of the top event in examined process was disproportionately high (0.29824). The Monte Carlo method was used for the simulation of the effect of decreasing the probability of basic events on the probability of the top event – the fault of the fluidity test.

Reliability analysis of helicopter emergency flotation system

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1001-1009
Author(s):  
Xing Guo ◽  
Jian-Hong Sun ◽  
Ke Liu ◽  
Tong Zhang ◽  
Ming-Qi Li ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Reliability Analysis ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Reliability Design ◽  
Minimal Cut Set ◽  
The Monte Carlo Method ◽  
Cut Set ◽  
Event Based

The reliability of the emergency flotation system of helicopters is analysed by using fault tree analysis and the Monte Carlo method. We constructed a fault tree with the failure of system as the top event and obtained the minimal cut set, the ranking of the structural importance of the bottom events and the probability of the occurrence of the top event. Based on the system fault tree, a Monte Carlo simulation model of the emergency flotation system is established by using Matlab/Simulink. The results show that the Monte Carlo method is feasible and effective for the reliability analysis of the emergency flotation systems of helicopters. Furthermore, the comparison between the criticality importance and mode importance of each subsystem suggests that the control component is the weakest part of the emergency flotation systems, thereby providing a basis for system reliability design and fault diagnosis.

A Comparison of Probabilistic-Monte Carlo and Fuzzy-Monte Carlo Simulation Approaches for Dynamic Fault Tree: Case of Renewable Power Systems

2020 ◽  
Author(s):  
Jafar Asghari ◽  
Mohammad Pourgol Mohammad
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Power Systems ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Tree Analysis ◽  
Renewable Energy Systems ◽  
Renewable Power ◽  
Dynamic Fault Tree ◽  
Different Types

Abstract Conventional Fault Tree Analysis (FTA) suffers from a variety of shortcomings which must be considered in critical analysis. The main disadvantage of FTA is its inability to model the dynamic failure behaviors of the components. Accordingly, Dynamic Fault Tree Analysis (DFTA) has been proposed to overcome such limitation. In this study, first, Monte Carlo simulation (MSC) approach is used to handle internal calculations of dynamic gates. The second main weakness of common FTA is about handling the different types of uncertainties. Hence, in the second step of this study, a combined of fuzzy numbers and MCS has been proposed to overcome the limitation of FTA in dealing with uncertainties. The main purpose of this paper is a comparative study on differences between MCS and Fuzzy-Monte Carlo simulation (FMCS) approaches for solving DFTA of a typical mechanical system. From available literatures, our proposed approaches have been demonstrated on different renewable energy systems, as case studies, and results are discussed. A comparison between MCS and FMCS shows that the results of FMCS method are reasonable and more realistic. Finally, in the last section, conclusions and some of the future wok are proposed.

FPGA-based Monte Carlo simulation for fault tree analysis

2004 ◽  
Vol 44 (6) ◽  
pp. 1017-1028 ◽  
Author(s):  
Alireza Ejlali ◽  
Seyed Ghassem Miremadi
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Tree Analysis

scholarly journals A Study on Reliability of Smart Meters based on Monte-Carlo Method and Fault Trees

2021 ◽  
Author(s):  
Ye Chen ◽  
Ziyi Chen ◽  
Yaohua Liao ◽  
Mengmeng Zhu ◽  
Zhihu Hong ◽  
...  
Keyword(s):  
Monte Carlo ◽  
Monte Carlo Method ◽  
Power Supply ◽  
Fault Tree ◽  
Reliability Function ◽  
Operational Reliability ◽  
Smart Meter ◽  
Smart Meters ◽  
The Monte Carlo Method ◽  
Technical Specifications

Smart meters are widely used in the power supply system, and their operational reliability is closely related to the user’s power supply reliability. It is difficult for intelligent power metering equipment to accurately predict its operational reliability and lifespan based on the existing technical specifications. In order to improve the accuracy of predicting the reliability and the maintenance cycle of the smart meter, this paper proposes a method for predicting the reliability of the smart meter based on the Monte Carlo method and fault tree. Firstly, the occurrence time of the bottom sampling event is simulated by the Monte-Carlo method based on the statistical data of the annual failure rate of each module of the smart meter. Then, according to the Fault Tree analysis of smart meters, the occurrence of the event is transformed into the fault time of the whole smart meters. The interval statistics are used to obtain the reliability value of the smart meter. In the end, the curve of the reliability function is obtained after fitting the reliability value. The results show that the reliability of the smart meter obeys the exponential distribution during the operation of 100 years. When it comes to the tenth year, the reliability is 0.9519. This algorithm provides a guide for accurately predicting its reliability and maintenance cycles by modularly analyzing the faults of smart meters.

scholarly journals FAULT TREE ANALYSIS OF FLY-OUTS IN METAL LATHE MACHINE OPERATIONS

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
AKINYEMI OLASUNKANMI ORIOLA ◽  
GIWA SOLOMON OLANREWAJU ◽  
ADEYEMI HEZEKIAH OLUWOLE ◽  
AKINTAN ADESHINAAYOMI LAWAL ◽  
MEBUDE OLADAPO
Keyword(s):  
Monte Carlo Simulation ◽  
Monte Carlo ◽  
Boolean Algebra ◽  
Fault Tree ◽  
Fault Tree Analysis ◽  
Tree Analysis ◽  
Before And After ◽  
Safety Interventions ◽  
Lathe Machine ◽  
Safety Intervention

The most probable accident in lathe machining has been identified to be fly-outs. This study aim at determining the causal factors leading to fly-out accidents during lathe machining operations and subsequently determine the probability of occurrence of fly-out accident. Fault tree analysis (FTA) was used to identify risk factors. Boolean algebra equations were used to analyse the probability of fault occurrence. Monte Carlo simulation was carried out using OpenFTA software and the output of 1000 iterations was compared with the output of Boolean algebra. Safety intervention alternatives were evaluated by comparative analysis of before and after implementation of safety measures. Twenty four (24) minimum cut sets comprising of 21 basic events and 3 undeveloped events were identified. The top event has probability of 0.748 signifying high likelihood for fly-out. Monte Carlo simulation gave lower and upper bounds probabilities of 0.725 and 0.773, respectively. The event of the chuck key not pulled out of the chuck before machining begins was however noted to have the highest contribution to the occurrence of fly-out accident. The result of safety intervention alternatives revealed that the probability of fly-out becomes 0.192 with a safety benefit of N27, 800 after the first tier implementation. Other tiers of safety interventions will see the probability of fly-out go further down. By this, safety engineer has a scale for effectiveness of respective safety intervention programmes. Key words: fly-out, accident, safety, intervention, lathe, machine, operation

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