Material- und Prozessmodellierung zur effizienten FEM-Berechnung der Verzugsentstehung beim Laser-Sintern von teilkristallinen Thermoplasten

Abstract

This thesis presents a method for fast numerical calculation of warpage in laser sintering of semicrystalline thermoplastics. The developed model is based on the simulation of the thermal interaction in the building chamber, caused by different thermal boundary conditions. For that purpose, a finite element mesh of the whole building space is generated. The interaction of the thermal boundary conditions causes a time dependent temperature eld, which influences the crystallization progress and in consequence the volume shrinkage. Subsequently to the thermal calculation, that shrinkage strain is used as time-space dependent mechanical load in a sequence of static mechanical FEM-computations of the part distortion. The developed approach allows the prediction of part warpage caused by macroscopic boundary conditions of real parts for the first time and has been used to analyse several test samples as well as real industrial parts.