In order to estimate the reliability of wind turbine gearbox based on the system level, a generalized stress-strength model is introduced. Considering that the system works properly under a variety of random stresses ...In order to estimate the reliability of wind turbine gearbox based on the system level, a generalized stress-strength model is introduced. Considering that the system works properly under a variety of random stresses which affect every component, the total stress on the system is given by a known linear combination of the stresses of all components. Then the strength of the system can be viewed as a linear combination of the strengths of relative components. In this model, stress and strength are independent of each other. Reliability of the system is the probability that strength exceeds stress. Finally, the reliability of wind turbine gearbox is estimated by the multivariable reliability calculation method. The corresponding result is compared with the results of reliability in the extreme cases(completely dependent and completely independent) by the traditional evaluation method.展开更多
As an essential lifeline engineering system,water distribution network should provide enough water to maintain people's life after earthquake in addition to working under daily operation.However,the design of wate...As an essential lifeline engineering system,water distribution network should provide enough water to maintain people's life after earthquake in addition to working under daily operation.However,the design of water distribution network usually ignores the influence of earthquake,resulting in water stoppage in large area during many recent strong earthquakes.This study introduced a seismic design approach of water distribution network,i.e.,topology optimization design.With network topology as the optimization goal and seismic reliability as the constraint,a topology optimization model for designing water distribution network under earthquake is established.Meanwhile,two element investment importance indexes,a pipeline investment importance index and a diameter investment importance index,are introduced to evaluate the importance of pipelines in water distribution network.Then,four combinational optimization algorithms,a genetic algorithm,a simulated annealing genetic algorithm,an ant colony algorithm and a particle swarm algorithm,are introduced to solve this optimization model.Moreover,these optimization algorithms are used to optimize a network with 19 nodes and 27 pipelines.The optimization results of these algorithms are compared with each other.展开更多
基金the National Natural Science Foundation of China(No.51265025)
文摘In order to estimate the reliability of wind turbine gearbox based on the system level, a generalized stress-strength model is introduced. Considering that the system works properly under a variety of random stresses which affect every component, the total stress on the system is given by a known linear combination of the stresses of all components. Then the strength of the system can be viewed as a linear combination of the strengths of relative components. In this model, stress and strength are independent of each other. Reliability of the system is the probability that strength exceeds stress. Finally, the reliability of wind turbine gearbox is estimated by the multivariable reliability calculation method. The corresponding result is compared with the results of reliability in the extreme cases(completely dependent and completely independent) by the traditional evaluation method.
基金supported by the Ministry of Science and Technology of China (Grant No. SLDRCE09-B-12)the Natural Science Funds for Young Scholars of China (Grant No.50808144)
文摘As an essential lifeline engineering system,water distribution network should provide enough water to maintain people's life after earthquake in addition to working under daily operation.However,the design of water distribution network usually ignores the influence of earthquake,resulting in water stoppage in large area during many recent strong earthquakes.This study introduced a seismic design approach of water distribution network,i.e.,topology optimization design.With network topology as the optimization goal and seismic reliability as the constraint,a topology optimization model for designing water distribution network under earthquake is established.Meanwhile,two element investment importance indexes,a pipeline investment importance index and a diameter investment importance index,are introduced to evaluate the importance of pipelines in water distribution network.Then,four combinational optimization algorithms,a genetic algorithm,a simulated annealing genetic algorithm,an ant colony algorithm and a particle swarm algorithm,are introduced to solve this optimization model.Moreover,these optimization algorithms are used to optimize a network with 19 nodes and 27 pipelines.The optimization results of these algorithms are compared with each other.
