Papers by Keyword: Fuzzy Reliability

Abstract: Rupture often happens when high-speed thin steel plate roller endures exchanging stress. Based on fuzzy theory, the paper discusses the fuzzy reliability design of roller with random variables and fuzzy variables, puts forward a basic method of digital simulation, and furthermore takes actions to improve the reliability of the rollers.

Abstract: To the widely used simple symmetric bevel gear differential, a fuzzy reliability-optimization mathematical model of a pair of bevel gear transmission is established, which used the bevel gear transmission as the research object, used the smallest volume of the gear transmission as the objective function, and used the end face module, the number of teeth and the coefficient of tooth face width as the design variables. Considering the randomness and fuzziness of the design parameters, an genetic algorithm control scheme was proposed for the optimal design, the numerical simulation results show that the volume of the gear transmission can be decreased by 3.36%, and the optimization design algorithm is more corresponded to engineering practice.

Abstract: The crack control of the thin-walled high pier for SanBei Bridge is effected by various uncertain factors such as loads, concrete strength and the release of hydration heat etc. Because of the fuzziness for the crack control of thin-walled high pier, it is difficult to accurately calculate the crack width to meet with the requirement of the limiting crack design for the structure. Based on the maximal permit crack formula issued in Concrete Design Specifications, the fuzziness analysis is made to the crack control reliability, the index of fuzzy reliable degrees of the girder maximal permit crack width is calculated by Monte Carlo method, and the sensitivity analysis to uncertain parameters is given to provide reference of the design for SanBei Bridge.

Abstract: The concepts of fuzzy reliability are introduced, and the model of fuzzy reliability calculation for cylinder liner wear life is set up. A fuzzy reliability calculation example of cylinder liner wear life for vehicle engine with 4 cylinders is given. The different of reliability calculation between the sample reliability and fuzzy reliability are discussed, and point out that the key for fuzzy reliability calculation is to decide the fuzzy range properly.

Abstract: The crack control of the concrete super wide box girder for New Jiujiang Changjiang River Bridge is effected by various uncertain factors such as loads, concrete strength and the release of hydration heat etc. Because of the fuzziness for the crack control of the super wide box girder, it is difficult to accurately calculate the crack width to meet with the requirement of the limiting crack design for the structure. Based on the maximal permit crack formula issued in “Concrete Design Specifications”, the fuzziness analysis is made to the crack control reliability, the index of fuzzy reliable degrees of the girder maximal permit crack width is calculated by Monte Carlo method, and the sensitivity analysis to uncertain parameters is given to provide reference of the design for River-Crossing Bridge.

Abstract: Introduced the conventional failure criterion of the precision of motion of mechanism and the analytical methods of reliability, and then focused on fuzzy failure criterion of precision, advanced mechanism fuzzy reliability formulas, and illuminated the application of this method.

Abstract: According to the basic principles and methods of the fuzzy reliability assessment to the existing bridge, RC rigid-frame arch bridge with Fuzzy reliability evaluation of a judgment factor sets of class I and class Ⅱare identified in this paper, aiming at the existing disease in this kind of bridge. Then, the fuzzy reliability comprehensive evaluation model of RC rigid-frame arch bridge is established. Meantime, the paper raises the membership function of each evaluation index; uses Analytic hierarchy process (AHP) to determine the weight vector of each factor. At last, a reliable practical analytical method for the evaluation of the existing RC rigid-frame arch bridge’s bearing capacity is obtained.

Abstract: In order to analyze the uncertainty existing in the stability of slope with geocell, the fuzziness of soil property parameters should be considered. In this paper, probability density function of structural performance function and membership function of the stability of slope with geocell was determined. The fuzzy reliability model of the stability of slope with geocell was established. The fuzzy reliability and fuzzy failure probability of slope with geocell instability were calculated, and the practicability of the calculated model was verified.

Abstract: Drag suction hopper dredger is dredg the hard compacted soil,dreghead teeth intensity will lead to an undersized cutting depth and a large cutting resistance, it raise failure probability. In this paper, investigate the relation between dredging depth，width,resistance and draghead teeth reliability influenced under different conditions,including various teeth,loads,navigating speeds and high-pressure jets.Discussed their effects on cutting depth,width and resistance.At last this paper obtain the reliability index and failure probability of the draghead teeth through the calculation numerical example.In this example,the method improvements efficiency for Draghead Teeth based on analysis on reliability.

Abstract: In order to rationalize the design of the worm-drive, the fuzzy reliability design method and robust design method were fully applied to develop the new model for fuzzy reliability optimization design of worm-drive with the minimum weight, minimum sliding-velocity, and minimum sensitivity as the objective function. The fuzzy optimization design result of the worm-drive was obtained by compiling MATLAB procedure. Compared with traditional design methods，the center distance was reduced by 33.3％, the sliding speed is reduced by 10.6%.The life of the worm-drive was raised by11.5％,and the wear quantity of the worm-drive was decreased by 0.1％after 100 hours' running.