Proposal of Some Cuttability Indexes for Evaluating the Performance of Mechanical Excavators Using Conical Picks

摘要

In this study, rock cuttability indexes are evaluated based on peak cutting force, specific energy and rock strength. For this purpose, a number of samples were collected from different parts of China and the mechanical properties of the samples were initially determined. Then, a series of cutting tests in unrelieved cutting mode were conducted at the linear rock cutting rig. The tests were performed at the cutting depths ranging from 3 mm to 18 mm. As a result of the tests, the effect of a significant cuttability index, which is the ratio of cutting force to cutting depth (FC/d), on the uniaxial compressive strength was investigated. Based on the acquired data from linear cutting test rig, the correlations between the ratio of FC/σ_c and cutting depth and also between the ratio of (SE/σ_c) and cutting depth were examined and their validity to be as new cuttability indexes were checked. High correlation coefficients among the cutting variables verified that the new cuttability index values can be successfully used for designing the cutterheads or the drums of mechanical excavators as well as evaluating their cutting efficiency.