Flexible Body Dynamics And Simulation Analysis Of Pneumatic Cylinder

As the most important actuator in pneumatic systems,pneumatic cylinder is widely used in various automatic production lines.With the continuous development of CAE technology and the requirement of lightweight and high reliability of pneumatic cylinder,the importance of pneumatic cylinder flexible body dynamics research is also increasing.Through solving and modeling the dynamics of cylinder flexible body,we can not only get various dynamic parameters such as the stress distribution,radial movement characteristics of pneumatic cylinder,but also provide guidance for the optimization design,failure analysis and reliability research of pneumatic cylinder.Based on this,combined with theoretical analysis,simulation and experimental test,this paper systematically studied the dynamics of cylinder flexible body,the cylinder stress and radial vibration.First of all,introduced the structure characteristics and performance characteristics of a single rod double acting cylinder,then according to the basic theory of gas dynamics,thermodynamics principle and Newton's second theorem,established the pneumatic cylinder dynamics model.Based on the theoretical model,the simulation was carried out with the MATLAB/SIMULINK software module,and the dynamic characteristics of the cylinder were analyzed.Secondly,the corresponding finite element model of pneumatic cylinder flexible body dynamics was established based on ANSYS/LS-DYNA software.The movement of pneumatic cylinder with a cantilever load was simulated,and the dynamic characteristics as well as stress distribution of pneumatic cylinder were analyzed.The time and location of the different parts' maximum stress were determined,and the failure mechanism of the pneumatic cylinder was analyzed according to the time varying stress characteristics of each part's maximum stress position,so as to provide basis for cylinder reliability analysis.Thirdly,with a view to the alternating stress characteristics on the different pneumatic cylinder parts,the bending vibration of the piston rod of a flexible cylinder was studied.The Eulerian beam model was used to replace the one-dimensional elastic rod model,so that the piston rod in the pneumatic cylinder was able to be abstracted as a time-varying length cantilever.Then the analytical model was established,and the model was solved based on the multi-scale method.At the same time,a finite element model was set up under the condition of uniform projecting boundary.The correctness of the mathematical model was verified by comparing the finite element results with the analytical solutions.Finally,the experimental platform was built,and the dynamic signals were collected by LABVIEW,which provided the experimental basis for the simulation model.The correctness of the dynamic simulation model and the finite element model were verified by the comparation between experimental data and previous results.By studying the dynamics and radial vibration model of pneumatic cylinder,this paper provides a new method of analysis for the stress analysis of the same type cylinder and the establishment of the radial vibration model.It provides a certain theoretical basis for the research of cylinder reliability,structure improvement and vibration control.