Determining the effects of physical, mechanical and textural properties of metamorphic stones on a chisel tool performance

Physical and mechanical property tests (uniaxial compressive strength, Brazilian tensile strength, Cerchar abrasivity index, Schmidt hammer hardness, Shore scleroscope hardness, density, static elasticity modulus, static Poisson’s ratio, P and S wave velocities, dynamic elasticity modulus and dynamic Poisson’s ratio) and textural analyses (texture coefficient, mean grain size and grain packing weighting) were carried out on metamorphic stones. To determine the cuttability of the studied stones; the samples were cut with a portable linear cutting machine using a standard chisel tool at different depths of cut in unrelieved (non-interactive) cutting mode. The average normal and cutting forces (FN, FC) and specific energy (SE) were measured. First, simple regression analyses were carried out to determine the best relationships between the dependent variable (chisel tool performance) and each independent variable (physical, mechanical and textural properties). Second, multiple linear regression analyses were performed using selected independent variables. Then, the simple and multiple linear regression models were developed to estimate the cutting performance of a chisel tool. Experimental studies show that laboratory cutting performance of chisel tool may be predicted based on the physical, mechanical and textural properties of the natural stones. The outcomes suggest that the selected properties are proportional to either specific energy or each of the forces measured during the cutting tests. This study also indicates that there are strong correlations between texture coefficient and cutting performance of chisel tool. The models developed in this study could be used by planners and natural stone companies for cost prognosis and cutting operation schedule.