| As a kind of engineering vehicle,emergency rescue vehicle is widely used at present,which has good mobility and all terrain trafficability.It is currently used in dangerous emergency rescue accidents such as urban traffic,tunnel collapse,road obstacles,forest fires,and debris flows.It has the capability of driving under complex road conditions such as snow,swamps,deserts,forests,etc.,in order to accomplish emergency rescue tasks.However,while working devices in complex environments,different wear and tear fatigue,joint damage may occur.Therefore,in the face of sudden Incident pass ability and mobility to further improve the fuel economy of engineering vehicles such as emergency rescue vehicles,it is necessary to develop the top-loading working device and complete the optimization design research to improve the emergency rescue vehicle.The top-loading operation device is mainly composed of slewing base,three-section operation arm,connecting rod,rocker and replaceable operation attachment.As an important operating device for emergency rescue of engineering vehicles,finite element analysis and optimization design research are carried out to ensure the safety characteristics and optimal operating performance of the bodywork device structure.The research topic comes from the school-enterprise cooperation project "Hybrid Operating System Based on Energy Recovery Technology",which is based on multifunctional unmanned wreckers and oriented to emergency rescue vehicles in different environments.Under the conditions,the task is unfolded,and the design and optimization of hinge position,strength and stiffness check,and realization of lightweight optimization design are carried out.Firstly,the structure of the multifunctional wrecker is briefly explained.Based on the 3D modeling software Pro/E,which establish a preliminary 3D model of the vehicle.This part mainly introduces the upper loading device.By comparing different operation methods,three sections of the operation arm are selected as the main form of the operation arm.Furthermore,according to the design method of the backhoe operating device and the relevant operating parameters,the geometric design of the hinge point was preliminarily designed.Finally,the hinge point position was determined and the work performance was evaluated.Secondly,this part optimizes the initial hinge position.A kinematics mathematical model of the three-joint working arm was established.Based on the RecurDyn dynamics simulation software,hinge points such as double booms and sticks were selected as design variables for parametric modeling.Besides,DOE test design analysis was performed to develop the optimal scheme.Further combined with Isight’s multi-objective optimization simulation software,the dual-boom lift,stick excavation,and bucket excavation were used as multi-objective optimization functions.The operating range was used as a constraint and selectes the NSGA-Ⅱ algorithm.Finally,the optimal position of 8 hinge points was obtained.What’s more,compared with the initial hinge point position and performance indicators,the research results show that both the maximum digging force and the working range parameters have been greatly improved.The research method can provide a reliable theoretical basis for the optimization of the hinge point position of the construction machinery operating device.Based on the overall layout of the emergency rescue vehicle and related finite element theoretical methods,the slewing base and the operating arm are simplified separately.Based on the joint simulation of HyperMesh and ANSYS software,a finite element model of the structure of the bodywork device was established.Through field investigations,three typical working conditions are designed for the slewing base to simulate the force situation of the slewing base.For the working arm,to simulate the complex stress conditions encountered in the actual operation process,designing eight typical working conditions can obtain the stress and displacement cloud diagrams under different working conditions.The research results show that the strength and rigidity of the slewing base and the working arm meet the safety characteristics.The maximum strain and stress area can be further optimized,which provide a theoretical basis for lightweight design.Finally,to improve the mobility and fuel economy,the lightweight design of the top-loading operation device is performed.Based on the ANSYS DesignXplorer module,according to the results of finite element analysis and design,a lightweight design scheme for the bodywork device was developed,the plate thickness was defined as the design variable,the maximum total displacement and the maximum stress were defined as the state variables.The lightweight design APDL language was written to address The optimization results are compared.Further check the strength and stiffness performance,the results show that it satisfies the safety performance.This solution reduced the weight of the slewing base structure to 8.6%,the weight reduction ratio of the working arm to 10.5%,the overall weight reduction of the top-loading operation device to 9.3%.The research results show that the lightweight effect is significant and has certain practical significance!... |
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