A Numerical and Experimental Analysis of the Dynamic Stability of Hydraulic Excavators

Abstract

The paper presents the results of a numerical and experimental analysis of the dynamic stability of hydraulic excavators. The analysis has employed the software developed on the basis of a defined general dynamic mathematical model of an excavator grounded in Newton-Euler equations as well as the measured quantities of the excavator operating state in exploitation conditions. The defined model is used to model the members of the excavator kinematic chain using rigid bodies while the actuators (hydraulic cylinders and hydraulic motors) of the excavator drive mechanisms are modeled with elastically dampened elements. The elastically dampened characteristics of the actuators are defined with regard to the size of the actuator as well as to the compressibility and temperature of the hydraulic oil used in the excavator hydrostatic drive system. To illustrate the analysis, the paper provides the results of the analysis of the dynamic stability of a 16000 kg tracked excavator equipped with a manipulator digging bucket of 0.6 m3 in capacity.

Analysis of the Influence of the Digging Position on the Loading of the Axial Bearing of Slewing Platform Drive Mechanisms in Hydraulic Excavators

“…The boundary forces of digging resistance Wim that can be overcome by the drive mechanisms of manipulator boom (i=3) and bucket (i=5), for the known оrtWm and the position of the kinematic chain of the excavator, during the operation of the maximum torques of mechanism Мpimax, are determined from the equilibrium conditions for axial joints Оi (i=3,5) of the manipulator: (18) where: Moi -total moment of the gravitational forces of the kinematic chain members and the drive mechanisms of the excavator and the weight of the material scooped with the bucket for the individual axes of joints Оi.…”

Measuring Deformations in the Telescopic Boom Under Static and Dynamic Load Conditions

“…Referring, for instance, to the case of the thin metal sheets the telescopic boom is made of, the more their thickness is reduced, the more unstable their behavior becomes [13]. Thus, every action dealing with a reduction in thickness needs to be thoroughly analyzed by theories including the study of second order effects, such as buckling of plates and sections [14][15][16][17].…”

“…An alternative solution is represented by the massive use of numerical calculations by means of tools such as FEM algorithms [16][17][18]. However, also in this case the information available can be non-conclusive, leaving the execution of validation tests as a last resource.…”

Numerical study of the hydraulic excavator overturning stability during performing lifting operations

“…Abo-Shanab and Sepehri 16 presented the development of a model that can adequately simulate the dynamic stability of manipulators mounted on moveable platforms. Janosevic et al 17 investigated the influence of the hydraulic transmission oil temperature on the excavator dynamic stability. The presented mathematical model takes into account the hydraulic cylinders compliance due to the hydraulic fluid compressibility.…”