Ivan Karin

Applications for a new production technology – analysis of linear flow-split linear guides

Within the collaborative research centre 666 “Integral Sheet Metal Design with Higher Order Bifurcations” the innovative manufacturing technologies linear flow-splitting and linear bend-splitting are researched that allow the continuous production of multi-chambered steel profiles in integral style. The massive forming processes create an ultra-fine grained microstructure in the forming area that is characterized by an increased hardness and lower surface roughness compared to as received material. These properties predestine the technology to be used in the production of linear guides. Additionally, the multi-chambered structure of the linear flow-split and -bend components can be used for function integration. To design and evaluate linear guides that use the whole technological potential, the research is focused on a macroscopic and a microscopic point of view.The macroscopic approach is targeting the development of linear flow-split linear guides with integrated functions to provide additional performance values to the established machine parts. Continuously produced guidance systems with innovative functionality can be introduced to a new market with the technology push approach. Preliminary designs of linear flow-split guidance systems and integrated functions are promising. Therefore, an approach to develop new functions for linear flow-split linear guides basing on calculation models and property networks is shown [1]. With this approach, optimized solutions can be created and possible design modifications can be derived. In this contribution, the development and integration of a clamping function for decelerating the slide is presented. Calculation models for analyzing the functionality are presented and validated by finite element models and experiments.The microscopic examination of the profiles aims to investigate the material behavior, particularly of the formed areas. Beside the conventional mechanical and fatigue properties of linear flow-split material ZStE500 [2], the present work focuses on the rolling contact fatigue. This is necessary to evaluate linear flow-split components regarding their eligibility with regard to the rolling contact fatigue behaviour. The Hertz theory for rolling contact fatigue is only valid for homogeneous materials [3]. The flow-split material ZStE500 shows a non-homogeneous behaviour and has to be analyzed with the Finite Element Method in order to determine stresses and strains. In comparison to simulation results with unformed and therefore homogeneous material, the effect of linear flow-split surfaces on the rolling contact behavior is demonstrated. Based on these results, it is possible to start experimental investigations on rolling contact fatigue of linear flow-split components to validate the FE model and determine the performance of linear flow-split flanges for rolling contact fatigue.Copyright

Prüfung linearer Bauteile auf Wälzfestigkeit

Kurzfassung Die Untersuchung der Wälzfestigkeit linearer Bauteile, die durch ein neuartiges Kaltumformverfahren höhere Oberflächenhärten und geringere Rauigkeiten aufweisen, stellt prozessbedingt eine sehr große Herausforderung dar und erscheint in diesem Zusammenhang sinnvoll. Denn die momentan auf dem Markt befindlichen Prüfmethoden zur Wälzfestigkeitsermittlung basieren auf der rotationssymmetrischen Geometrie der Prüfkörper und stellen somit ein Ausschlusskriterium für lineare Bauteile dar. Um jedoch die spezifischen Eigenschaften, die aus dem Spaltprofilierprozess resultieren und die an die lineare Form der Spaltprofile gebunden sind, so real wie möglich simulieren zu können, wurde ein neuartiger Wälzfestigkeitsprüfstand für lineare Bauteile konstruiert, entwickelt und in Betrieb genommen. Mit diesem Prüfstand ist eine Bewertung der Wälzfestigkeit linearer Bauteile möglich.