Design of μ-CNC machining centre with carbon/epoxy composite-aluminium hybrid structures containing friction layers for high damping capacity

Abstract

The focus of this paper is on the design of machine tool structures, such as columns and spindle holders, for a 3-axis mu-CNC machining centre. Carbon/epoxy composite-aluminium hybrid structures with friction layers were used to increase structural damping. Two types of hybrid column structures were proposed. Finite element analyses were carried out to calculate both the static deflection of columns due to deadweight and also the first natural frequency of machine tool structures as a function of the stacking angle and thickness of the carbon/epoxy composites. To increase damping capacity, a friction layer was inserted between the aluminium-composite interface. For the design of the structures the stacking angle and the thickness ratio of the composites were considered as major design variables. And the most appropriate stacking sequence of the composite-aluminium hybrid structure employing a friction layer was determined using finite element analyses and vibration tests. (C) 2009 Elsevier Ltd. All rights reserved.