| This thesis relies on the background of a simply supported beam bridge,and the bridge’s span is 10 m and the main beam is simply supported hollow section girder bridge.And use finite element analysis software to model.Analyzing the dynamic response of the telescopic device under the vehicle load effect.Combined with the actual situation,this thesis analyze the numerical simulation of telescopic device on three conditions: different speed,different weights and due to the installation or worse road caused the car jump problem.Under the different conditions to study the mechanical properties and fatigue damage failure of the telescopic device.Then get conclusion on bridge speed and weight limit problem.The main work of this thesis includes:(1)Using LS-DYNA,LS-PrePost,HyperMesh finite element analysis software and the knowledge of simply supported beams to establish solid model.And control the detail scale of the telescopic device.The important point of the model is the detail scale of the telescopic device,correctly simulate contact between the telescopic device and bridge deck,and correctly simulate the coupling between the vehicle and bridges.(2)Based on the different vehicle speed,analyzed the mechanical properties of telescopic device.Compared with the displacement and stress of the telescopic device under the different vehicle speeds,get the influence level of the vehicle speed on the damage of the telescopic device.(3)Based on the different quality of vehicles,analyzed the mechanical properties of telescopic device.Compared with the results,get the influence level of vehicle quality on the damage of telescopic device.(4)Based on the different jumping vehicles,analyzed the mechanical properties of telescopic device.Compared with the displacement and stress of the telescopic device,get the influence level of the jumping phenomenon on the damage of the telescopic device.(5)Using the rain flow counting to organized the stress curve,and get the stress spectrum.Combining the Miner linear fatigue cumulative damage theory,get the damage level of the telescopic device under the different conditions.And analyzed fatigue damage of the telescopic device.Get the conclusion on bridge speed and weight limit problem after much research.And the conclusion include:(1)Over speed vehicles does not cause accelerated destruction of the telescopic device.Vehicle speed is mainly aimed at the safe of drivers.(2)Overweight vehicles does cause accelerated destruction of the telescopic device.So weight limit must be carried out according to the design of the bridge,and avoiding the accelerated destruction of the telescopic device.(3)The car jump problem does cause accelerated destruction of the telescopic device.So must repairing the bridge deck when the bridge deck appears potholes,foreign body,and avoiding the accelerated destruction of the telescopic device. |
