A theory is formulated using a feedback loop to represent the chatter mechanism. This theory permits the calculation of borderlines of stability for a machine tool system having a structure with n-degrees of freedom. A cutting stiffness table is presented in which data from the literature are given in a form of cutting stiffness per unit width of cut for various materials. The dynamic behavior of the cutting process is explored in depth yielding an understanding and qualitative description of observed dynamic behavior. The theory of transfer functions of structures has been derived enabling the prediction of structure dynamics of simple continuous systems. Measured and computed stability diagrams are presented demonstrating the validity of the developed stability theory. From the research program initial chatter specifications have been formulated. Such a specification, if established, would define the ratio of minimum directional dynamic stiffness of the structure over the rated horsepower of the machine tool. (Author).

This project has been engaged in a manufacturing methods program which was directed at the problem of resolving the theory of self-excited chatter such that it would encompass milling operations, in addition to turning and drilling operations. Concurrent with this investigation, parallel tasks were conducted to investigate analytical techniques that could be used to predict the static and dynamic characteristics of machine tool structures at the drawing stage, to investigate observed phenomena of the cutting process associated with metal cutting dynamics, and to investigate techniques whereby chatter specifications could be formulated and used to measure the chatter-free performance of machine tools. (Author).

To determine the dynamic behaviour of gear drives under preload and under running conditions an electrohydraulic rotatory exciter was built and tested on a 18 stage milling machine gear box. Using this device the natural frequencies, dynamic flexibilities and the degree of damping for the drive are determined. Using a digital computer programme the values of natural frequencies and static flexibilities are also computed and the results of measurement and calculation are compared. To determine the dynamics of the cutting process an equipment consisting of a cutting force dynamometer, relative displacement pick up, electromagnetic exciter of high force capability, power supply to the exciter and an electronic device for the instantaneous measurement of transfer function were developed. The performance characteristics of this set up are presented. Besides these special problems, an examination was made as to how far a special method of description, computation and measurement ('Multiplex'-description) developed for the investigation of the stiffness and stability of machine tools will be suitable as a basis for the development of acceptability standards for machine tools and practicability of this method was confirmed. (Author).

Machine Tool Structures, Volume 1 deals with fundamental theories and calculation methods for machine tool structures. Experimental investigations into stiffness are discussed, along with the application of the results to the design of machine tool structures. Topics covered range from static and dynamic stiffness to chatter in metal cutting, stability in machine tools, and deformations of machine tool structures. This volume is divided into three sections and opens with a discussion on stiffness specifications and the effect of stiffness on the behavior of the machine under forced vibration conditions. The following chapters explore the stability of the machine structure against chatter; methods of stability analysis; tests and principles of dampers; chatter during grinding operations; and stresses and deformations of closed box structures subjected to bending and shear. Calculation methods for determining stiffness constants of a structure's individual parts, as well as methods for determining the resulting stiffnesses, modal shapes, and their parameters, are also described. The final chapter presents systematic procedures for the analysis of machine tool structures. This book is intended for university students, research workers, and designers.