| In recent years,emergency monitoring Trailer with its advantages of safety,high mobility,low center of gravity and flexible operation has become the main emergency monitoring tool in mountainous and hilly areas,which is widely used in various countries.The problems of large volume and heavy mass of emergency monitoring Trailer directly affect the transportation efficiency.As an important load-bearing part of emergency monitoring trailer,the weight of emergency monitoring trailer body skeleton accounts for about 30% ~ 40% of the weight of emergency monitoring Trailer.On the premise of ensuring the load-bearing performance such as frame rigidity and strength,the weight of emergency monitoring trailer can be effectively reduced,which can improve the market competitiveness of emergency monitoring Trailer.In this paper,the emergency monitoring trailer body skeleton is taken as the research object.The local topology optimization and sensitivity analysis are used to realize the lightweight of the body skeleton.The fatigue life of the optimized body skeleton is analyzed to verify the safety of the optimization results.The main contents of this paper are as follows:1.Finite element analysis of emergency monitoring trailer body frame.The finite element model of the body frame is established in ANSYS,and the static analysis is carried out under four typical working conditions: horizontal bending condition,emergency braking condition,emergency turning condition and ultimate torsion condition,and the stress value and deformation value of the body frame structure are obtained.Through the modal analysis of the body frame structure,the first six modal frequencies and modes are obtained.The results of static and modal analysis show that the body frame meets the design requirements and has design redundancy.2.Topology optimization design of emergency monitoring trailer body frame.Using the local topology optimization method,taking the density of the optimization area as the design variable,taking the minimum flexibility of the body skeleton as the optimization objective,and taking the volume of the design area as the constraint,the topology optimization mathematical model of the emergency monitoring trailer body skeleton structure is established.Using HyperMesh software,the topology optimization design is carried out for the upper,lower,left and right sides and the middle of the body skeleton respectively,and according to the extension According to the optimization results,design requirements and manufacturing process requirements,the topology optimization area is redesigned,and the emergency monitoring trailer body framework structure after topology optimization is obtained.3.Lightweight analysis of trailer body frame for emergency monitoring.Through the sensitivity analysis,the components that are not sensitive to the structural performance of the body frame but sensitive to the mass of the body frame are obtained.The wall thickness of the components is taken as the design variable,the minimum mass of the body frame and the maximum first-order modal frequency are taken as the optimization objectives,and the maximum stress and displacement of the body frame structure under various working conditions are less than the design fixed value as the constraint conditions.The optimization of the body frame is established In the model,the new thickness of each design variable after optimization is obtained;the performance of the body skeleton before and after optimization is compared,the results show that the mass of the body skeleton is reduced from 614.99 kg to 528.42 kg,86.57 kg and 14.08% on the premise of meeting the design requirements,and good weight reduction effect is achieved.4.Fatigue life analysis of trailer body frame after optimization.Select the linear fatigue cumulative damage rule,and use the fatigue tool module in ANSYS software to analyze the optimized body skeleton’s fatigue life,obtain the body skeleton’s fatigue life,safety factor and fatigue damage,and verify the safety of the optimized body skeleton by comparing with the theoretical fatigue safety life.The results show that this paper uses the local topology optimization and sensitivity analysis method to carry out the lightweight design of the emergency monitoring trailer body skeleton,which reduces the mass of the body skeleton by86.57 kg and the weight reduction range by 14.08%.At the same time,tthe life analysis of the optimized emergency monitoring trailer body framework fatigue verifies the safety of the optimization results. |
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