scholarly journals LIFE-TIME PREDICTION FOR POLYMER MATERIALS

2021 ◽  
Vol 59 (5) ◽  
Author(s):  
Chinh Thuy Nguyen ◽  
Hoang Thai
Keyword(s):  
Thermal Degradation ◽  
Fatigue Testing ◽  
Life Time ◽  
Working Life ◽  
Accelerated Testing ◽  
Polymer Materials ◽  
Accelerated Ageing ◽  
Time Prediction ◽  
Structure Morphology ◽  
Safe Working

Polymer testing including natural, accelerated testing or creep and fatigue testing, etc. is very important to evaluate the changes in properties, structure, morphology and durability of polymer materials. This is also the basis for experts to predict life-time or service working life or safe working life of polymer materials. This review presents an overview of the life-time prediction for polymer materials owing to natural tests or accelerated ageing tests and the methods for extrapolation of data from induced thermal degradation.  

Lifetime Distribution Estimation of Boot Seals in Automotive Applications by Bayesian Method

2006 ◽  
Vol 129 (3) ◽  
pp. 275-282 ◽  
Author(s):  
Fabrice Guerin ◽  
Ridha Hambli
Keyword(s):  
Finite Element ◽  
Bayesian Method ◽  
Life Time ◽  
Automotive Applications ◽  
Fatigue Lifetime ◽  
Time Prediction ◽  
Steering Mechanism ◽  
Market Requirements ◽  
Distribution Parameters ◽  
Lifetime Testing

The constantly increasing market requirements of high quality vehicles ask for the automotive manufacturers to perform lifetime testing to verify the reliability levels of new products. A common problem is that only a small number of examples of a component of system can be tested. In the automotive applications, mechanical components subjected to cyclic loading have to be designed against fatigue. Boot seals are used to protect velocity joint and steering mechanisms in automobiles. These flexible components must accommodate the motions associated with angulation of the steering mechanism. Some regions of the boot seal are always in contact with an internal metal shaft, while other areas come into contact with the metal shaft during angulation. In addition, the boot seal may also come into contact with itself, both internally and externally. The contacting regions affect the performance and longevity of the boot seal. In this paper, the Bayesian estimation of lognormal distribution parameters (usually used to define the fatigue lifetime of rubber components) is studied to improve the accuracy of estimation in incorporating the available knowledge on the product. In particular, the finite element results and expert belief are considered as prior knowledge. For life time prediction by finite element method, a model based on Brown–Miller law was developed for the boot seal rubber-like material.

Life-time prediction for rocks under static compressive and tensile loads: a new simulation approach

2009 ◽  
Vol 4 (1) ◽  
pp. 73-78 ◽  
Author(s):  
H. Konietzky ◽  
A. Heftenberger ◽  
M. Feige
Keyword(s):  
Life Time ◽  
Simulation Approach ◽  
Time Prediction

scholarly journals ASSESSMENT OF IMPORTANCE OF WORKING LIFE QUALITY ELEMENTS WHILE LABOR EFFICIENCY RESEARCH OF INDUSTRIAL WORKERS

2018 ◽  
Vol 15 (3) ◽  
pp. 460-469
Author(s):  
M. S. Mizya ◽  
E. P. Tevs
Keyword(s):  
Life Quality ◽  
Working Life ◽  
Industrial Sector ◽  
Industrial Workers ◽  
Decent Work ◽  
Quality Of Working Life ◽  
Labor Efficiency ◽  
Production Organization ◽  
Safe Working

Introduction. The article is devoted to analysis of the indicators’ dynamic that characterizes the quality of working life level in the Russian industrial sector. The aim of research is to identify and assess the influence of working life quality on economic efficiency of labor.Methods. The system of indicators for the period from 2005 to 2015 is determined on the basis of the analysis of existing assessment methods of working life quality and on official statistics data, which reflects the main elements of working life quality. Therefore, the most significant indicators of working life elements in terms of labor efficiency are determined by means of correlation analysis.Results. It is revealed that social guarantees, decent wages and safe working conditions, i.e. objective characteristics of working life quality, have the greatest impact on labor efficiency. As a result, the subjective characteristics such as job satisfaction and opportunities for self-expression and selfrealization, despite the long period of the market economy development, continue to play a secondary role. The demonstrated problem confirms the fact that the main block of working life quality for industrial workers is not fully ensured and is deterrent to the growth of labor efficiency as a socio-economic category.Discussion and conclusions. The results of this research indicate the availability of reserves to improve labor efficiency through the usage of modern methods of production organization to ensure economic conditions of decent work of industrial workers.

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