作者: Shi Lian Xu, Rui Hong Wang, Ruo Qi Li, Ren Ping Xu

摘要: The brittle is crippling the application of bioceramic. The compound bioceramic is a new biomaterial being widely applied in medical treatments and its fracture toughness is an important mechanical behaviors. In this paper, we introduce the manufacturing method of the compound bioceramic and experiment facilities for its fracture toughness, investigate its probability distribution for the experimental data and conduct the test for fit. We conclude that the experimental data for the toughness fracture of the compound bioceramic obey the two-parameter Weibull distribution, introduce the analyzing method for the upper confidence limit curve and lower confidence limit curve and study the reliability and confidence level of the fracture toughness of the compound bioceramic.

3003

作者: Fu Zhou Feng, Wei Xing, Ai Wei Si, Guang Ping Wu

摘要: Reliability of equipment has long been considered as an important quality characteristic. Traditional methods of equipment reliability assessment are based on lifetime data. With equipment being much more reliable and the growing need for developing new equipments within shorter period and at lower cost, we can hardly get enough lifetime data in many cases. Performance degradation data can also be used for reliability assessment. This paper is mainly researched on reliability of a certain diesel engine. Through analyzing the failure mode and failure mechanism, performance degradation parameters of the diesel engine is selected as compression pressure in a cylinder while driven by an electrical motor. Based on a long time accumulation on performance degradation data, two methods of degradation path fitting and degradation value distribution are tried in this paper to evaluate reliability of the diesel engine. Besides, the regulation of the reliability variation is given by the results of the assessment.

481

作者: Bu Zheng Wen, Jian Min Li, Zhong Tao Pei, Sheng Yu, Cuan Yang Sun, Hai Xie

摘要: Statistical analysis of load spectrum is an important part on structural fatigue life and reliability research, it is generally considered that axle’s load spectrum follows Weibull distribution. This paper tested ZL50 loader’s loading history of different working conditions , and obtained the corresponding load spectrum by rain-flow counting method, then analyzed three distributions’ (normal distribution, lognormal distribution, Weibull distribution) fitting degree of load spectrum and effect on the fatigue reliability. Results show that the highest fitting degree of distribution function should be used to fit load spectrum, which can reduce the error in structural fatigue reliability prediction.

456

作者: Chang Gao Xia, Meng Zhang, Xiang Gao, Zhen Yu Zhang

摘要: The mixed distribution model and the maximum entropy model are used to represent service load of the vehicle clutch. The parameters of those models are estimated with different methods. The findings indicate that maximum entropy distribution can accurately describe different statistical features of random variables as minimally prejudiced probability distribution if order of the distribution function is properly selected, and that the mixed Weibull distribution shows super performance of the complicated statistical model expression. The parameters of those models are estimated by optimization based on non-linear least squares.

5244

作者: Chun Yuan Liu, Meng Xuan Zhao, Yu Liu

摘要: The paper introduces the basic principles of vertical bearing capacity of the pile by using static load test, establish the random site theory model of the bearing capacity of prestressed pipe pile foundations calculation, calculates and statistics the try count ratio of vertical bearing capacity of 144 prestressed pipe pile in Tianjin, work out calculation procedures of JC method, calculate reliability index of vertical bearing capacity and analyze calculation results. In the last, we build a model using the finite element software, analysis the displacement of pile top under earthquake, evaluates the horizontal bearing capacity of prestressed pipe pile.

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