This study analyzed the passive arching effect under eccentric loading by developing a series of trapdoor discrete numerical models.The numerical models were validated by comparison with laboratory test results.The de...This study analyzed the passive arching effect under eccentric loading by developing a series of trapdoor discrete numerical models.The numerical models were validated by comparison with laboratory test results.The deformation pattern,soil arching ratio,force chain distribution,and coordination number under various surcharge magnitudes and deviation distances were analyzed.The numerical results showed that the deformation diagram of soil particles can be divided into three zones:principal displacement zone,transition zone,and static zone.With an increase in the surcharge magnitude,the range of the principal displacement zone decreased,but the range of the transition region increased.The curve of the soil arching ratio on the trapdoor can be divided into three phases,which can be well characterized by the tangent modulus.The passive arching effect is degraded by a surcharge.The ulti-mate soil arching ratio could be approximated as a W-shaped distribution along the+x-direction.With an increase in the trapdoor displacement,the force chain on the trapdoor gradually expanded outward to form an inverted funnel shape.The most powerful force on the trapdoor was mainly distributed on its edge.The average coordination number decreased gradually as the trapdoor moved upward.展开更多
Mountain cities are complex asymmetric dynamic network architectures,and the flight of UAVs in this environment is subject to various constraints,while efficiency is a crucial factor in the trajectory planning of poli...Mountain cities are complex asymmetric dynamic network architectures,and the flight of UAVs in this environment is subject to various constraints,while efficiency is a crucial factor in the trajectory planning of police UAVs,which need to maintain high efficiency and safe flight paths between their starting and ending points,but the traditional trajectory planning method cannot meet the requirements of rapid maneuvering of police UAVs.To achieve this,a 3D terrain map is built,an objective function is established for the flight cost in the UAV trajectory planning process,and a planning algorithm called particle swarm optimization bat algorithm(PSOBA)is proposed.PSOBA combines the characteristics of the bat algorithm(BA)and the particle swarm optimization algorithm(PSO)to improve population diversity and resolve the delayed convergence issue in the last phases of BA.Simulation results show that PSOBA is more effective than BA,with a search time for the best solution that is approximately 20.43%shorter and a convergence value of the objective function that is approximately 38%smaller.PSOBA is also able to plan a quicker,shorter,and safer flight path compared to other trail planning algorithms that enhance the bat algorithm.These findings suggest that PSOBA is a powerful algorithm with potential application value in UAV trajectory planning control in the mobile intelligence era.Contribute to the service of public social security.展开更多
基金supported by the National Natural Science Foundation of China(Nos.52090081 and 51938008)Key Research and Development Program of Guangdong Province(No.2019B111105001)the Natural Science Foundation of Shenzhen(No.JCYJ20210324094607020).
文摘This study analyzed the passive arching effect under eccentric loading by developing a series of trapdoor discrete numerical models.The numerical models were validated by comparison with laboratory test results.The deformation pattern,soil arching ratio,force chain distribution,and coordination number under various surcharge magnitudes and deviation distances were analyzed.The numerical results showed that the deformation diagram of soil particles can be divided into three zones:principal displacement zone,transition zone,and static zone.With an increase in the surcharge magnitude,the range of the principal displacement zone decreased,but the range of the transition region increased.The curve of the soil arching ratio on the trapdoor can be divided into three phases,which can be well characterized by the tangent modulus.The passive arching effect is degraded by a surcharge.The ulti-mate soil arching ratio could be approximated as a W-shaped distribution along the+x-direction.With an increase in the trapdoor displacement,the force chain on the trapdoor gradually expanded outward to form an inverted funnel shape.The most powerful force on the trapdoor was mainly distributed on its edge.The average coordination number decreased gradually as the trapdoor moved upward.
基金Supported by the Science and Technology Research Program of Chongqing Municipal Education Commission(KJZD-K202201203)Chongqing Three Gorges University and the Public Security Bureau of Wanzhou District,Chongqing(wzstc20210302,wzstc20220310)。
文摘Mountain cities are complex asymmetric dynamic network architectures,and the flight of UAVs in this environment is subject to various constraints,while efficiency is a crucial factor in the trajectory planning of police UAVs,which need to maintain high efficiency and safe flight paths between their starting and ending points,but the traditional trajectory planning method cannot meet the requirements of rapid maneuvering of police UAVs.To achieve this,a 3D terrain map is built,an objective function is established for the flight cost in the UAV trajectory planning process,and a planning algorithm called particle swarm optimization bat algorithm(PSOBA)is proposed.PSOBA combines the characteristics of the bat algorithm(BA)and the particle swarm optimization algorithm(PSO)to improve population diversity and resolve the delayed convergence issue in the last phases of BA.Simulation results show that PSOBA is more effective than BA,with a search time for the best solution that is approximately 20.43%shorter and a convergence value of the objective function that is approximately 38%smaller.PSOBA is also able to plan a quicker,shorter,and safer flight path compared to other trail planning algorithms that enhance the bat algorithm.These findings suggest that PSOBA is a powerful algorithm with potential application value in UAV trajectory planning control in the mobile intelligence era.Contribute to the service of public social security.
