scholarly journals Periodical Preventive Maintenance Schedule for Minimum Cost Using Geometric Process Model in Accelerated life Testing With Exponentiated Weibull Failure Data

2018 ◽  
Vol 28 (3) ◽  
pp. 333-352
2011 ◽  
Vol 121-126 ◽  
pp. 1274-1278 ◽  
Author(s):  
Juan Chen ◽  
De Yi Wang ◽  
Yong Ling Fu ◽  
Xiao Ye Qi

This paper discusses the principle and method of Double-Crossed Step-Down-Stress Accelerated Life Testing (DCSDS-ALT) for pneumatic cylinders. As to pneumatic cylinder, the step-down-stress testing failure physics can be described as cumulative degradation model. Temperature and frequency are normally chosen as the test stresses. The failure data obtained under DCSDS-ALT testing steps can be converted to those under constant stress testing. And the reliability specifications can be derived accordingly. To compare Double-stress ALTs with traditional constant stress testing shows Double-stress ALTs can meet the accuracy demand. The 5% of average lifetime estimation error and 1.85% of the characteristic lifetime error are very satisfying for pneumatic industrial lifetime prediction.


Engevista ◽  
2010 ◽  
Vol 7 (1) ◽  
Author(s):  
Daniel I. de Souza Jr. ◽  
Kamalesh Somani

The main objective of life testing is to obtain information concerning failure. This information should then be used in order to quantify reliability, improve product reliability, and to determine whether safety and reliability goals are being met. The amount of time available for testing directly at use conditions, that is, with practical test times and realistic (relatively) small test sample sizes, could be considerably less than the component’s expected lifetime. To overcome such a problem, there is the life-testing alternative aimed at forcing components to fail by testing them at much higher than the intended application conditions. By doing this, we will get failure data that can be fitted to life distribution models. To go from the failure rate obtained at high stress to what a product or service is likely to experience at much lower stress, under use conditions, we will need additional modeling. These models are known as acceleration models. The accelerated life testing concept is such that a component, operating under predetermined (correct) levels of increased stress, will have exactly the same failure mechanism as observed when used at normal stress levels. For example, if the time of testing is measured in cycles, then the time squeezing may only require increasing the number of cycles per unit of time. In this study, we will develop an accelerated life-testing model in which the underlying sampling distribution is the three-parameter Weibull model. We will be assuming a linear acceleration condition. An example will illustrate the application of the proposed accelerated life-testing model.  


2018 ◽  
Vol 24 (8) ◽  
pp. 5859-5865
Author(s):  
C Kalaiselvan ◽  
Lokavarapu Bhaskara Rao

Compare to previous decay, now days consumer expectation is very high about the electronic product what they are going to purchase. The consumer analyzes the quality of the product with the product competitors. The electronic component manufacturer is under immersive pressure to show their reliability of their product and maintain their place in the market. Reliability engineering helps to announce the guaranty period of the electronic product. Highly Accelerated Life Testing (HALT) is the latest technology in the reliability field for testing the electronic components. The highly accelerated life testing is conducted at accelerated stress level to generate more failure data in a short span of time. The Capacitor test board is used to test the most commonly used X5R Ceramic Capacitor to identify the time to failure data (TTF). The time to failure data follows a statistical distribution to find out the mean time to failure data (MTTF) at accelerated conditions. The time to failure data of capacitor at accelerated condition is converted to actual conditions and integrated with PLM solution using SQL Query, Java and HTML. The integration helps to reduce product time to market and increase the profitability of the manufacturer.


2015 ◽  
Vol 2015 ◽  
pp. 1-9
Author(s):  
Ma Xiaobing ◽  
Zhang Yongbo

An accelerated life testing investigation was conducted on a composite cylinder that consists of aluminum alloy and T700 carbon fiber. The ultimate failure stress predictions of cylinders were obtained by the mixing rule and verified by the blasting static pressure method. Based on the stress prediction of cylinder under working conditions, the constant stress accelerated life test of the cylinder was designed. However, the failure data cannot be sufficiently obtained by the accelerated life test due to the time limitation. Therefore, most of the data presented to be high censored in high stress level and zero-failure data in low stress level. When using the traditional method for rupture life prediction, the results showed to be of lower confidence. In this study, the consistency of failure mechanism for carbon fiber and cylinder was analyzed firstly. According to the analysis result, the statistical test information of carbon fiber could be utilized for the accelerated model constitution. Then, rupture life prediction method for cylinder was proposed based on the accelerated life test data and carbon fiber test data. In this way, the life prediction accuracy of cylinder could be improved obviously, and the results showed that the accuracy of this method increased by 35%.


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