An extended procedure for convective boundary conditions on transient thermal simulations of machine tools

The need of reliable structural properties of machine tools in the development phase are becoming increasingly important due to mounting accuracy demands and shrinking development periods. The finite element method is the most established tool applied in this context. Currently, calculating thermal properties and compensation of thermally caused shifts are mainly the focus of simulation studies due to high performance and the usage of dry processing. The accuracy with which thermal properties can be mapped today is measurably lower than current static and dynamic properties. The reason is due to strong interaction of the specific physical effects and the complexity of pertinent constraints. With constrained parameters the impact caused is defining the convective heat transmission. The heat transmission coefficient can be calculated analytically or numerically. This article is presenting a method that allows permanent adaptation of this coefficient to make it possible to better apply convective heat transmission to time-variable thermal simulations especially for mechanical based finite element models.