Vibration-reducing Characteristics Analysis Of Multi-layer Tubular Stand-off Damping Structure

The crawler construction vehicle is an indispensable backbone equipment in modern construction.It often operates in a “off-road” environment,causing the vibration shock of the vehicle to be very severe,and the vibration becomes more prominent with the increase of its model.This has a certain impact on the life of the vehicle components and the physical and mental health of the driver.In view of the above problems,Based on the literature research,this paper analyzes the damping vibration-reducing of the crawler bulldozer drive sprocket.The specific research work is as follows:(1)The vibration behavior of the tracked vehicle traveling system is discussed.The vibration response characteristics of the integrated drive sprocket(without damping)and the split drive sprocket(with damping)are compared and analyzed.Taking the crawler bulldozer as an example,the vibration equation of the walking system is established.The amplitude-frequency characteristics of the crawler walking system and the final drive system with and without damping are analyzed.At the same time,the force transmission rate of the damping structure is the objective function,and the range of stiffness and damping coefficient of the damping structure is obtained.(2)For the split drive sprocket,a multi-layer tubular stand-off-layer sandwiched structure is proposed,and the corresponding vibration model is established.The tensile test and MATLAB software are used to fit the damping layer material characteristic parameter values,Under the common working conditions of bulldozers(bulldozing,cutting),the vibration characteristics and transient dynamic response of the multi-layer damping structure(three-layer,five-layer tubular constrained damping structure,four-layer tubular stand-off-layer sandwiched structure)are discussed based on ANSYS software.(3)Based on wave dynamics and three-dimensional elastic theory,the relationship between modal parameters and boundary conditions of multi-layer structures is obtained,and the equations of motion and vibration state equations of any node of multi-layer structure are derived.The modal analysis method is used to extract the natural frequencies and natural modes of several different damping structures,and the harmonic response analysis is performed in the high frequency and low frequency range respectively.The above three finite element dynamics analysis impose the same displacement boundary constraints,and the periodic load constraints are divided into two cases,one changing with the rotation angle of the driving wheel,and the other one taking time as the dependent variable.(4)The influence of stand-off-layer parameters on the vibration characteristics and dynamic response of tubular stand-off-layer sandwiched structure is studied.In the time domain and frequency domain,the dynamic response and vibration suppression effects of different stand-off-layer thickness with or without change in the total thickness of the structure are discussed respectively.The dynamic response and vibration characteristics of different stand-off-layer elastic moduli in the time domain are observed.When the stand-off-layer is located in different positions of the structure,the influence of the transition layer on the vibration characteristics and dynamic response of the structure is discussed.The results show that the parameters of the stand-off-layer have a significant impact on the vibration characteristics and dynamic response of the structure.The research results in this paper can provide theoretical basis and research methods for the design and further optimization of multi-layer tubular stand-off-layer sandwiched structure in construction applications,and also provide a reference for the study of multi-layer damping structures.