Most previous investigations on interference effects of tall buildings under wind actions focused on the wind induced interference effects between two buildings,and the interference effects of three or more buildings ...Most previous investigations on interference effects of tall buildings under wind actions focused on the wind induced interference effects between two buildings,and the interference effects of three or more buildings have seldom been studied so far due to the huge workload involved in experiments and data processing.In this paper,mean and dynamic force/response interference effects and peak wind pressure interference effects of two and three tall buildings,especially the three-building configuration,are investigated through a series of wind tunnel tests on typical tall building models using high frequency force balance technique and wind pressure measurements.Furthermore,the present paper focuses on the effects of parameters,including breadth ratio and height ratio of the buildings and terrain category,on the interference factors and derives relevant regression results for the interference factors.展开更多
Currently,direct braking-force measurement under dynamic conditions requires a considerable modification to the vehicles and has poor compatibility because there are many types of vehicles.Thus,in this paper,an indire...Currently,direct braking-force measurement under dynamic conditions requires a considerable modification to the vehicles and has poor compatibility because there are many types of vehicles.Thus,in this paper,an indirect measurement method of new-energy vehicles,braking force under dynamic braking conditions is proposed.The mechanical wheel and axle model at low/idling/high speeds is established using the piston-pressure formula,force transfer in the brake-wheel cylinder,relative movement between the wheel and the roller,among others.On this basis,the relationship between wheel braking force and roller-linear acceleration is further derived.Our method does not alter existing vehicle structures or sensor types.The standard sealing bolt is temporarily replaced with a hydraulic sensor for coefficient calibration.Afterward,the braking force can be indirectly calculated using the roller-linear velocity data.The method has characteristics of efficiency and high accuracy without refitting vehicles.展开更多
基金supported by the National Natural Science Foundation of China (90715040)
文摘Most previous investigations on interference effects of tall buildings under wind actions focused on the wind induced interference effects between two buildings,and the interference effects of three or more buildings have seldom been studied so far due to the huge workload involved in experiments and data processing.In this paper,mean and dynamic force/response interference effects and peak wind pressure interference effects of two and three tall buildings,especially the three-building configuration,are investigated through a series of wind tunnel tests on typical tall building models using high frequency force balance technique and wind pressure measurements.Furthermore,the present paper focuses on the effects of parameters,including breadth ratio and height ratio of the buildings and terrain category,on the interference factors and derives relevant regression results for the interference factors.
文摘Currently,direct braking-force measurement under dynamic conditions requires a considerable modification to the vehicles and has poor compatibility because there are many types of vehicles.Thus,in this paper,an indirect measurement method of new-energy vehicles,braking force under dynamic braking conditions is proposed.The mechanical wheel and axle model at low/idling/high speeds is established using the piston-pressure formula,force transfer in the brake-wheel cylinder,relative movement between the wheel and the roller,among others.On this basis,the relationship between wheel braking force and roller-linear acceleration is further derived.Our method does not alter existing vehicle structures or sensor types.The standard sealing bolt is temporarily replaced with a hydraulic sensor for coefficient calibration.Afterward,the braking force can be indirectly calculated using the roller-linear velocity data.The method has characteristics of efficiency and high accuracy without refitting vehicles.