Research On Ground Pressure Distribution Characteristics Of Crawler Walking Device

Recently,the heavy-duty construction vehicles are developing in the direction of large-scale,and the crawler ground pressure is also increasing.When the ground pressure of crawler walking device exceeds the bearing capacity of the foundation,it may cause uneven settlement or even collapse of the foundation,which may lead to tilting or even overturning of the whole machine.Therefore,the research on the ground pressure distribution characteristics of the crawler walking device is urgently needed.In this paper,we take the heavy spreader as an example,the mathematical model of ground pressure distribution was established,and the influence law of equipment parameters and foundation parameters on the ground pressure was studied.The main research contents are as follows.(1)On the basis of the research on the ground pressure determination method of the crawler walking device,the mathematical model of the average ground pressure is firstly established assuming that the crawler walking device is rigid and the foundation is flexible.Further,considering the influence of the change of the center of gravity,a two-dimensional and three-dimensional linear distribution mathematical model of the ground pressure is established.(2)The finite element model of the heavy spreader was established.Through ANSYS Workbench software,the ground pressure distribution of the heavy spreader track was simulated.The influence law of the number,radius,thickness of track rollers,and foundation parameters on the ground pressure distribution of the crawler walking device is discussed: increasing the number of rollers can reduce the maximum value of the crawler ground pressure of the heavy spreader and improve the uniformity of the ground pressure distribution.The simulation results show that the radius and thickness of the track rollers of the crawler walking device have little influence on the ground pressure;under the premise of no large deformation of the foundation,the Young’s modulus and Poisson’s ratio of the foundation have a greater influence on the ground pressure.(3)For the current problem of uneven distribution of ground pressure,based on Solid Works and MATLAB software,the variation law of the spatial coordinate value of the center of gravity with the attitude of the heavy spreader(with its receiving arm rotation angle,discharging arm uplift angle and car body slewing support rotation angle)is studied and the data are fitted.To verify the correctness of the above mentioned two-dimensional mathematical model,the ground pressure was calculated by ANSYS Workbench simulation software,and the maximum error was 5.6%,thus verifying the correctness of the proposed model.The study analyzed the change trend of the ground pressure with the rotation angle of the receiving arm,the uplift angle of the discharge arm and the rotation angle of the slewing support of the body of the heavy spreader.(4)The mathematical model of dynamic ground pressure distribution was established.Based on MATLAB software,the ground pressure magnitude of the crawler walking device at different moments was obtained by numerical calculation.In order to verify the correctness of the dynamic mathematical model,a 3D digital prototype model of the crawler walking device was established in Solid Works software,and the dynamic ground pressure of the crawler walking device were calculated and obtained through the Recur Dyn software.The study analyzed the trend of dynamic distribution of ground pressure with the spacing of track rollers,number of the rollers,width of track plate,tensioning force and driving force.The results show that the maximum value of ground pressure increases by 0.064 MPa when the distance between rollers increases by 200mm;the maximum value of ground pressure decreases by 0.085 MPa when the number of the rollers increases by 2;the maximum value of ground pressure decreases by 0.053 MPa when the width of track plate increases by 60mm;the maximum value of ground pressure decreases when the tensioning force increases.The change of driving force has little effect on the ground pressure distribution.The research results of this paper can provide some theoretical basis for the design of various crawler walking equipment.At the same time,it can also provide some reference for the treatment of different working foundations.