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Abstract
The objective of this research is to design, develop and analyse a novel machine tool based on the concept of parallel kinematic structure. This concept is widely recognised as having many significant advantages over conventional machine tools based on open kinematic structures, and accordingly is the subject of several major research efforts in many high-industrialised countries.
Tiara is the a parallel kinematic machine tool developed at McMaster University that has a unique design basis, in particular with regards to fixed strut length mechanism, use of inclined motion axes, five-sided machining dexterity, and inclined platform design. These characteristics, in addition to being unique from other published designs, have several advantages from both performances and economic perspective.
This thesis describes the design and development of the Tiara hexapod, the investigation of its kinematics, the analysis of its dynamics, and the improvements of its characteristics. Fully parametric analytical models and in-house built tools are used to estimate and quantify the machine tool performances, and to perform an original numerical optimisation method to establish the design parameters that maximize the machining performances. Solid-body models are used with CAD software to design the main components of the machine. Finite element models are used in specialized FEA software to verify the rigidity of the components and to define directions for iterative design improvements. Fully parametric multi-body dynamic models are defined in a dedicated dynamic software package to determine the loading and dynamic characteristics of each component of the kinematic chain and to use them in component design.
Modal tests are carried out to establish the dynamic behaviour of the designed machine tool and to perform design refinements that improve the cutting accuracy of the machine by increasing the rigidity of the components and by reducing the propagation of the vibrations with various damping techniques.
