Study of the stiffness for predicting the accuracy of machine tools

Abstract

• Machining processes are frequently faced 
with the challenge of achieving more 
and more precision and surface qualities. 
These requirements are usually attained 
taking into account some process variables, 
including the cutting parameters and 
the use or not of refrigerant, leaving 
aside the mechanical aspects associated 
with the infl uence of machine tool itself. 
There are many sources of error linked 
with machine-workpiece interaction, but, 
in general, we can summarize them in 
to two types of error: quasi-static and 
dynamic. This paper shows the infl uence of 
quasi-static error caused by low machine 
rigidity on the accuracy applied on two very 
different processes: turning and grinding. 
For the study of the static stiffness of these 
two machines, two different methods are 
proposed, both of them equally valid. The 
fi rst one is based on separated parameters 
and the second one on fi nite elements.