Weibull Analysis Research Papers - Academia.edu (original) (raw)

In Weibull accelerated life test analysis (ALT) with two or more variables (X2, X3, ... Xk), we estimated, in joint form, the parameters of the life stress model r{X(t)} and one shape parameter β. These were then used to extrapolate the conclusions to the operational level. However, these conclusions are biased because in the experiment design (DOE) used, each combination of the variables presents its own Weibull family (βi, ηi). Thus the estimated β is not representative. On the other hand, since (βi, ηi) is determined by the variance of the logarithm of the lifetime data σt2 , the response variance σy2 and the correlation coefficient R2, which increases when variables are added to the analysis, β is always overestimated. In this paper, the problem is statistically addressed and based on the Weibull families (βi, ηi) a vector Yη is estimated and used to determine the parameters of r{X(t)}. Finally, based on the variance σy2 of each level, the variance of the operational level σop2 is estimated and used to determine the operational shape parameter βop. The efficiency of the proposed method is shown by numerical applications and by comparing its results with those of the maximum likelihood method (ML).

- by and +3
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- Experimental Design, Multiple Linear Regression, ALT Analysis, Weibull Analysis
- by Serge Demidenko
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- Statistical Analysis, Computer Hardware, High Voltage, Stress Testing
- by Katharina Fischer
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- Technology, Performance, Simulation, Model validation

La velocidad del viento cambia continuamente, por lo que es necesario describirlo de forma estadística. Es conveniente establecer un modelo de las frecuencias de las velocidades del viento que venga descrito por una función matemática... more

- by Juan Andres Tapia Segura
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- Weibull distribution, Weibull Analysis
- by Andre Kleyner
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- Engineering, Monte Carlo, Forecasting, Mathematical Sciences
- by Sean Gallagher
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- Mechanical Engineering, Biomedical Engineering, Humans, Clinical Biomechanics

Abstract
This research paper will focus on the optimization of maintenance intervals to develop cost efficiencies for the airlines. The focus will be geared toward how Republic Airlines can increase the reliability on the main windshield for its Embraer 170 fleet. It is hypothesized that in order to reduce removals, it’s advisable for the airline to reduce inspection intervals of the moisture seal on the main windshield. A Conditional Weibull distribution analysis between the two data sets will be used to support the theory between the (a) 1,000 hour (check interval), and (b) 500 hour (reduced check interval). The desired outcome will result in a p value less than .05 from the ANOVA test to suggest a significant increase in reliability. By lowering the maintenance inspection interval from 1,000 flight hours to 500 hours, it will reduce the number of main windshield removals and result in an improved reliability of 10%.
Keywords: aviation maintenance, optimized maintenance interval, Embraer, PPG transparencies, aviation maintenance programs, aircraft windshields, statistical methods

- by Erik Tiefel
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- Airline Economics, Repair and Maintenance, Optimization, Airlines
- by James Tsoi
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- Mechanical Engineering, Materials Science, Dentistry, Fatigue
- by Ludwig J Gauckler
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- Engineering, Glass, Scanning Electron Microscopy, Dental Materials
- by Julian F V Vincent
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- Materials Engineering, Mechanical Engineering, Civil Engineering, Potato
- by Andre Kleyner
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- Engineering, Monte Carlo Simulation, Forecasting, Uncertainty
- by Horieh Moosavi and +1
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- Engineering, Water, Nanoindentation, Dental Materials
- by Peter Niemz
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- Growth rings, Tensile Strength, Weibull Analysis, Bioresources
- by Nikolaos Alexopoulos and +1
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- Materials Engineering, Mechanical Engineering, Weibull Analysis
- by Murat Tiryakioglu
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- Materials Science, Fatigue, Metals, Tensile testing
- by Eliseu Münchow
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- Dentistry, Water, Structural Reliability, Dental Materials
- by Andre Kleyner
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- Engineering, Monte Carlo Simulation, Forecasting, Uncertainty

espanolEn el analisis de pruebas de vida acelerada Weibull con dos o mas variables aceleradas (X2,X3,...Xk) , estimamos en forma conjunta los parametros del modelo de relacion vida esfuerzo r{X(t)} y un parametro de forma s. Despues estos parametros son utilizados para extrapolar las conclusiones al nivel operacional. Como sea, estas conclusiones estan sesgadas debido a que dentro del diseno de experimentos (DOE) utilizado, cada combinacion de las variables presenta su propia familia Weibull (si,ni) . De esa forma la estimada s no es representativa. Por otro lado, dado que s esta determinada por la varianza del logaritmo de los tiempos de vida o²t , por la varianza de la respuesta o²y y por el coeficiente de correlacion , el cual crece cuando se agregan variables al analisis, s es siempre sobre estimada. En este articulo, el problema es estadisticamente identificado y basado sobre las familias Weibull (si,ni) un vector Yn es estimado y utilizado para determinar los parametros de r{X...

- by Piña Monarrez
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- Engineering, Experimental Design, Multiple Linear Regression, ALT Analysis
- by Peter Knights
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- Engineering, Computer Science, Reliability Engineering, Electric Motor
- by Murat Tiryakioglu
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- Materials Engineering, Mechanical Engineering, Weibull Analysis
- by Benjamin Lhorente
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- Engineering, Reliability Engineering, Electric Motor, Mathematical Sciences
- by Carlos Avila
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- Experimental Design, Multiple Linear Regression, ALT Analysis, Weibull Analysis
- by Yuji Iwamoto
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- Materials Engineering, Mechanical Engineering, Porosity, Diffusion
- by Evandro Piva and +1
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- Dentistry, Water, Structural Reliability, Dental Materials