A Fundamental Overview of Accelerated Testing Analytical Models

1998 ◽  
Vol 41 (1) ◽  
pp. 16-20 ◽  
Author(s):  
Hank Caruso ◽  
Abhijit Dasgupta
Keyword(s):  
Fatigue Damage ◽  
Accelerated Life Testing ◽  
Analytical Models ◽  
Aging Effects ◽  
Chemical Aging ◽  
Life Estimation ◽  
Mechanical Fatigue ◽  
Accelerated Life ◽  
Steady State Temperature ◽  
Acceleration Model

This paper describes analytical models that are commonly used for product life estimation and accelerated life testing. Model descriptions include: Miner's "Rule" for describing accumulated fatigue damage; Coffin-Manson nonlinear power law, often applied to mechanical fatigue damage; Rudra model for CFF failures; Arrhenius steady-state temperature acceleration model for estimating chemical aging effects; Peck's model for accelerated combined temperature-humidity effects; and Kemeny model for combined temperature and voltage acceleration effects. The general form of these models will be presented along with specific guidance regarding: relative strengths and appropriate applications for each model; limitations and sources of uncertainty for each model; and example values for exponents and material coefficients.

Accelerated Life Testing Method of Transmission

2006 ◽  
Vol 326-328 ◽  
pp. 1865-1868
Author(s):  
Hyoung Eui Kim ◽  
Doh Sik Kim ◽  
Yoon Pyo Lee ◽  
Yung Chul Yoo
Keyword(s):  
Fatigue Damage ◽  
Service Use ◽  
Life Time ◽  
Accelerated Life Testing ◽  
Accelerated Life Test ◽  
Life Testing ◽  
Step Process ◽  
Testing Method ◽  
Accelerated Life ◽  
Cumulative Fatigue Damage

In this study, we proposed a process of an accelerated life testing method of 5-speed manual transmissions used in vehicles, which loads are consisted of multiple alternating loads. The entire process of an 5-speed manual transmission’s accelerated life testing method where no failures are allowed, is a process that requires an abundance of assumptions, and other factors that are estimates such as the shape parameter, beta() and the fatigue damage exponent (x). And the process is consisted of 7-step process. From the 1-setp, which is the deriving the service(use) torque and speed(rpm) profile of the transmission, to the 7-step, we could determine the accelerated life time, the accelerated torque and the accelerated speed(rpm), which are the equivalent cumulative fatigue damage. Also, we have performed accelerated life test on 5-speed manual transmission by using the following 7-step process.

Study on Reliability Growth Test Method for Disc Magazine and Manipulator

2014 ◽  
Vol 904 ◽  
pp. 335-339
Author(s):  
Jing Ying Duan ◽  
Chang Jing Fu
Keyword(s):  
Test Data ◽  
Weibull Model ◽  
Small Sample ◽  
Accelerated Life Testing ◽  
Test Method ◽  
Distribution Model ◽  
Accelerated Life ◽  
Acceleration Model ◽  
Selection Of

The life distribution model and accelerated life testing methods of the disc magazine and manipulator were discussed. The small sample determination of truncation test was performed to QY011 and a batch of test data under the accelerated stress at the selection of vibration as the accelerated stress have been obtained. The reliability life index under certain stress level was analyzed through established the accelerated probability weighted Weibull model and inversed power law model for acceleration model. According to the acceleration model and statistical analysis of test data, the QY011 reliability life level of QY011 disc magazine and manipulator under the normal working conditions were calculated.

scholarly journals Accelerated Life Testing of Subsea Equipment Under Hydrostatic Pressure

2011 ◽  
Vol 45 (5) ◽  
pp. 42-54
Author(s):  
Amar Thiraviam ◽  
Linda Malone
Keyword(s):  
Exponential Model ◽  
Accelerated Life Testing ◽  
Life Testing ◽  
Component Level ◽  
Inverse Power Law ◽  
Accelerated Life ◽  
Acceleration Model ◽  
Critical Components ◽  
The Individual ◽  
Life Predictions

AbstractAccelerated life testing (ALT) is an effective method of demonstrating and improving product reliability in applications where the products are expected to perform for a long period of time. ALT accelerates a given failure mode by testing at amplified stress level(s) in excess of operational limits. Statistical analysis (parameter estimation) is then performed on the data, based on an acceleration model to make life predictions at use level. The acceleration model thus forms the basis of ALT methodology. Well-established accelerated models such as the Arrhenius model and the Inverse Power Law (IPL) model exist for key stresses such as temperature and voltage, but there are other stresses, like subsea pressure, where there are no clear models of choice. This research proposes a pressure-life (acceleration) model for the first time for life prediction under subsea pressure for key mechanical/physical failure mechanisms.Three independent accelerated tests were conducted, and their results were analyzed to identify the best model for the pressure-life relationship. The testing included material tests in standard coupons to investigate the effect of subsea pressure on key physical, mechanical, and electrical properties. Tests were also conducted at the component level on critical components that function as a pressure barrier. By comparing the likelihood values of multiple reasonable candidate models for the individual tests, the exponential model was identified as a good model for the pressure-life relationship. In addition to consistently providing good fit among the three tests, the exponential model was also validated with over 10 years of field data and demonstrated several characteristics that enable robust life predictions in a variety of scenarios. In addition, the research also used the process of Bayesian analysis to incorporate prior information from field and test data to bolster the results and increase the confidence in the predictions from the proposed model.

POWER-LAW ACCELERATED BIRNBAUM–SAUNDERS LIFE MODELS

2000 ◽  
Vol 07 (01) ◽  
pp. 1-15
Author(s):  
W. J. OWEN ◽  
W. J. PADGETT
Keyword(s):  
Power Law ◽  
Testing Procedure ◽  
Accelerated Life Testing ◽  
Data Set ◽  
Inverse Power Law ◽  
Accelerated Life ◽  
Acceleration Model ◽  
Life Model ◽  
Accelerated Life Model ◽  
Selection Of

An accelerated life testing procedure can reduce the lifetime of a material by observing the material's behavior under higher levels of stress than what is normally encountered. Useful inference hinges on the selection of an appropriate lifetime distribution and the substitution of an acceleration model for a distribution parameter, such as the mean or scale. The (inverse) power-law model is one such acceleration model that has applications to fatigue studies in metals, where failure tends to be crack-induced. The Birnbaum–Saunders distribution was developed to model fatigue in materials where the failure of a specimen is due to the propagation of a dominant crack. This paper will compare two Birnbaum–Saunders type models from the literature (that have power-law accelerated features) with a new but distinctive model proposed here. The new model is an accelerated life model for a reparameterization of the baseline distribution. Comparison of the three models will be via the aluminum coupon data set from Birnbaum and Saunders5 and issues of accelerated testing will be discussed.

ACCELERATED LIFE TESTING OF COMPONENTS OF NUCLEAR RESEARCH REACTORS

2016 ◽  
Author(s):  
Vanderley Vasconcelos ◽  
WELLINGTON SOARES ◽  
Antonio Carlos Lopes da Costa ◽  
Raíssa Oliveira Marques
Keyword(s):  
Nuclear Research ◽  
Accelerated Life Testing ◽  
Life Testing ◽  
Research Reactors ◽  
Accelerated Life

scholarly journals Current challenges in modelling vibrational fatigue and fracture of structures: a review

2021 ◽  
Vol 43 (2) ◽  
Author(s):  
Khangamlung Kamei ◽  
Muhammad A. Khan
Keyword(s):  
Fatigue Damage ◽  
Thermal Environment ◽  
Research Work ◽  
Working Life ◽  
Stochastic Response ◽  
Metal Structures ◽  
Life Estimation ◽  
The Past ◽  
New Directions ◽  
Fatigue And Fracture

AbstractFatigue damage is a concern in the engineering applications particularly for metal structures. The design phase of a structure considers factors that can prevent or delay the fatigue and fracture failures and increase its working life. This paper compiled some of the past efforts to share the modelling challenges. It provides an overview on the existing research complexities in the area of fatigue and fracture modelling. This paper reviews the previous research work under five prominent challenges: assessing fatigue damage accurately under the vibration-based loads, complications in fatigue and fracture life estimation, intricacy in fatigue crack propagation, quantification of cracks and stochastic response of structure under thermal environment. In the conclusion, the authors have suggested new directions of work that still require comprehensive research efforts to bridge the existing gap in the current academic domain due to the highlighted challenges.

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