Studies of stress and strain in bucket teeth of earth-moving machines

Abstract

This paper aims to analyze the existing designs of bucket teeth in earth-moving machines with the purpose of selecting an optimal design in a scientifically grounded manner. The research objects included six design models of teeth of earth-moving machines made of alloyed manganese steel 110G13L. Teeth models were built using the KOMPAS-3D software. Lateral elastic internal stresses and elastic strains in the teeth models were determined using the COMSOL Multiphysics software. Lateral elastic internal stresses and elastic strains were calculated for the applied load of 9 kN in soft soil and 90 kN in rocky soil. Optimal teeth designs were determined for soils of various hardness. In soft soils, a ripper tooth and a combined curved tooth with an extra ripper tooth showed the optimum combination of efficiency and strength. Thus, provided that the elastic strain of a standard tooth in soft soils equals 100% and depending on the initial state, a ripper tooth and a combined curved tooth with an extra ripper tooth showed the strain values of 30–50% and 32–35%, respectively. In hard soils, a combined curved tooth with an extra ripper tooth and a regular curved tooth showed the optimum combination of efficiency and strength. Thus, provided that the elastic strain of a standard tooth in hard soil equals 100% and depending on the initial state, a combined curved tooth with an extra ripper tooth and a curved tooth showed the strain values of 18–20% and 42–45%, respectively. The feasibility of using buckets with combined teeth of optimal design in earth-moving machines was scientifically substantiated. Future research will investigate various bucket designs of earth-moving machines to find their optimal modifications for soils of various hardness.