Strength Analysis And Structural Optimization Of Elevator Car Frame Based On Finite Element Method

With the increase of tall buildings in our city,the elevator industry has developed,at present,some elevator manufacturers still use the theory of material mechanics to analyze the force of elevator car frames,because of the complexity of elevators,the calculation results are generally low accuracy.Based on the finite element analysis method,this paper analyzes the strength of elevator car frame,and on the basis of this to improve,to ensure the safety of the premise to achieve the elevator car frame lightweight goal.This paper takes the medium speed elevator with the largest usage as the research object,the allowable stresses are selected for the strength check of the car frame.At present,the current national standards do not specify the strength check method of the elevator car frame,so draw on American standard and refer to Japan standard,in order to ensure the safety of passengers and elevators,conservative allowable stresses are selected.Pro/E modeling software is used for 3D modeling of elevator car frame,importing ANSYS finite element analysis software,carrying out finite element analysis under 100% full load,125% overload and partial load conditions.It is concluded that the maximum stress points of the vertical beam and the lower beam are located at the joints,the stress at different positions varies little;and the maximum stress points of the upper beam are located at the holes,the stress distribution shows the trend of decreasing gradually from middle to both ends,and the strength check all accord with the safety,it is also found that 125% overload and 100% load 3/4 bias load are more dangerous working conditions.For verifying the accuracy of the finite element model,based on the testing of the material properties of the Q235 A of the elevator car frame,the stress tests of elevator car frame under typical working conditions were carried out.The measured results show that the stress of each part of the car frame fluctuates only slightly during the acceleration and deceleration of the elevator,the measured stress of each measuring point of the car frame is in accordance with the finite element simulation results,which indicates that the real stress responses of the car frame can be better reflected by the finite element model and loading calculation methods.Based on the results of finite element analysis,the traditional optimization and topology optimization methods are used to optimize the elevator car frame,after optimizations,the quality of the components of elevator car frame was reduced by12.1%,and the quality of the car frame part(upper beam,vertical beam and lower beam)was reduced by 19.6%.Finite element analysis and strength check of the second optimized car frame are carried out,maximum stresses of upper beam and lower beam are reduced,and maximum stresses of vertical beam are increased,all are less than the allowable stresses,to ensure the safety of the car frame after optimizations.