Safety Evaluation Of Quayside Container Crane Based On Improved Entropy Weight Method And Variable Fuzzy Set Method

Quayside container crane is a special equipment for container loading and unloading in modern ports.Its safety incidents account for about 30% of the total port safety incidents.The coverage of accident causes includes from the design and manufacture stage to the use and maintenance stage.The accidents may cause economic loss such as machine damage,or even major safety accidents such as casualties.On the one hand,studying the safety evaluation methods of quayside bridges is helpful to improve the safety evaluation system of quayside bridges,and on the other hand,it can be used as an auxiliary means to determine the safety of quayside bridges,so as to improve the safety production and operation level of ports,increase economic benefits and reduce the occurrence of safety accidents.The specific research contents and work of this paper are as follows:(1)Based on the statistics of fault type of quayside bridges,the concrete evaluation index of quayside bridges was simplified,and according to the standards,some qualitative indexes were transformed into quantitative ones.Then the qualitative indexes were reduced,the evaluation content of each index was determined,the quantitative index dimensionless method and quantitative index quantization method and the division of complete machine evaluation scale of quayside bridges were introduced,so as to establish a comprehensive and scientific quayside bridge evaluation index system as much as possible.(2)The subjective weight of the index was obtained by the fuzzy analytic hierarchy process,the objective weight of the index was obtained by the entropy weight method,and the subjective and objective weights were combined by the game theory grouping method to determine the final weight.Then the entropy weight method was improved to solve the problem that the traditional entropy weight method is unreasonable in entropy distribution when the entropy value approaches 1 and the existing formula of the improved entropy weight method is complicated.Later,the superiority of the improved method was proved by practical cases.(3)According to the characteristics that the evaluation criterion of each index was an interval,the variable fuzzy sets method was adopted to carry out the safety evaluation of quayside bridges,but the determination process of relative membership degree matrix in traditional variable fuzzy sets method is relatively complicated,the linear relationship of relative membership function at different levels was used to establish the three simplified feature relational expressions of relative membership degree function,which solved the problem.Then the above advantages were proved by formulas and case analysis and comparison.(4)Taking the real data of a quayside bridge as an example,the safety evaluation process of quayside bridges was introduced.The data of quantitative and qualitative index was obtained through field detection and expert scoring.The subjective weight was obtained by fuzzy analytic hierarchy process,the objective weight was obtained by improved entropy weight method,and the final weight was obtained by combining subjective weight with objective weight according to improved game theory group method.Then the safety level of quayside bridge was determined according to the improved variable fuzzy set method.Finally,by improving the variable fuzzy set method,the final safety level of quayside bridge was determined layer by layer.Therefore,the feasibility of the quayside bridge evaluation system established in this study was verified.