Date of Award

1998

Document Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Mechanical Engineering

First Advisor

Su-Seng Pang

Second Advisor

Chihdar Yang

Abstract

Diamond-impregnated segmented circular blade sawing is one of the most effective, versatile, and extensively used methods of processing rock and other hard materials, such as granite, marble, concrete and asphalt. For many years, it has been known that chip thickness is one of the most significant parameters in the understanding of the sawing process, and other variables such as force and power have been correlated with it. In this work, the material chipping geometries have been mathematically defined and derived through kinematics analysis. From these chipping geometries, chip area and thickness relations have been obtained. A relation for the mean chip thickness-to-grit spacing ratio has also been obtained as a function of independent non-dimensional machining parameter ratios. The effects of these independent non-dimensional parameters on the mean thickness were also investigated. The results show an excellent agreement between the new chipping model and the older ones. However, at moderately small to large depth of cut to blade diameter ratios values, the new model yields a more exact result. The grit spacing parameter used in the mean chip thickness-to-grit spacing ratio equation has also been examined. Methods were formulated to (a) analytically and (b) numerically compute an explicit value for the grit spacing. A comparison has also been made to verify the results for the grit spacing term. The results showed excellent agreement between the presented models and experimental data. Finally, the stress distribution of the segmented blade was investigated through the use of finite element analysis. Saw blades with various slot parameters were investigated and compared. The applied forces included the saw blade cutting force as well as the centrifugal force due to rotation. Plane stress conditions were assumed during the investigation. The maximum stress for each geometry was located and its magnitude was determined. In summary, an improved slot shape has been suggested to minimize the stress concentration and thereby increase the saw blade fatigue life.

ISBN

9780599213807

Pages

97

Share

COinS