THE STIFFNESS OF STATICALLY INDETERMINATE SPINDLE SYSTEMS WITH NONLINEAR BEARINGS

The paper relates to the design of machine tool spindles for optimal s tatic stiffness using computer simulation. Current trends are to have computer algorithms which are reliable and allow efficient and accurat e programming. In particular, algorithms which may be repeatedly appli ed to model complex systems, by gradually building up to the final sys tem, are extremely useful. The algorithms described allow the analysis of complex statically indeterminate spindles and provide stiffness va lues and deflected shapes. The algorithms may also be used with nonlin ear bearing stiffnesses thus enabling the resulting nonlinear static s tiffness of the spindle system to be predicted. The algorithms are als o fast compared to normal methods and therefore allow the designer to investigate a range of design possibilities interactively.