Research

Resource Efficiency by Optimising Static Friction

When designing frictionally engaged component joints, such as flange and screw connections for example, precise knowledge of the friction coefficient plays an important role. In addition, torque transmission can be ensured with the help of higher static friction values, which in turn reduces the number of connecting elements and their dimensions. In this project, static friction values were calculated on standardised test stands and geometric parameters derived. The share of friction mechanisms and the friction characteristics of frictionally engaged surface pairings could be shown separately for the first time through simulation. Investigations of PVD (Physical Vapour Deposition) coatings, thermal sprayed coatings and laser structures show that it is possible to significantly increase friction co-efficiency with all three methods. Thus the user has different variations at his disposal, which can be selected based on application-specific criteria. With the project results, the user is capable of designing frictionally engaged component connections with greater resource efficiency in the future.

» With the results of the GECKO cluster project, we have increased our understanding of static friction significantly. The success rests especially on the excellent collaboration between the five scientific institutions and the members of the project user committee. «
Dr.-Ing. Anton Stich (AUDI AG)

Motivation

Frictionally engaged component joints, such as flange and screw connections for example, are present in many applications. Precise knowledge of their friction coefficient is essential for dimensioning. In addition, torque transmission can be ensured with the help of higher static friction values, which in turn reduces the number of connecting elements and their dimensions. Which parameters influence static friction and how static friction values can be increased through laser structuring and coatings were the questions this project focused on.

Methodology

The experimental static friction appraisal on standardised test stands formed the starting point. This was followed by the development of geometric parameters, which correlated with the static friction values. Using a newly developed 3D FEM Contact and Friction model for coarse surfaces, the simulation was conducted. It served especially to determine the share of active friction mechanism deformation and adhesion. The investigation of friction enhancing PVD coatings and laser structures was a further focus.

Result

With the results it is possible to design frictionally engaged connections with greater resource efficiency in the future. The user has at his disposal a large number of static friction values, friction characteristics as well as valuable insights into the design of frictionally engaged surfaces. Furthermore, the test stands and the standardised test methods could be used for determining individual friction coefficient certifications. Using simulations it was possible to show the share of friction mechanisms and the friction characteristics for friction surface pairings separately. The newly developed friction enhancing coating system and laser structuring offers the user great potential for maximising static friction values. There are different variations available, which can be selected based on the specific application.

FVV Documentation

GECKO (Cluster) | Design and identification of characteristic data of friction contact optimised surfaces

Sub-project I | Characteristic data analysis and synthesis | Project No. 1075 | AiF Funding ID 17228 BR

Sub-project II | Metrological description of the geometric properties of frictionally engaged surfaces | Project No. 1075 | DFG Funding ID DI 617/27-1

Sub-project III | Simulation of friction grip | Project No. M3408 | DFG Funding ID DE 582/13-1

Sub-project IV | Friction-hard coatings | Project No. 1076 | AiF Funding ID 17230 BR

Sub-project V | Friction-laser structuring | Project No. 1077 | AiF Funding ID 17229 BR

Themis

Status
Finalised

Programme
Public Funding

Budget
1.144.970,00 EUR EUR

Time Period
2011-07-01 to 2014-06-30

Federal Ministry for Economic Affairs and Energy (BMWi)

Scharnhorststrasse 34-37
10115 Berlin
Germany

German Federation of Industrial Research Associations (AiF) e.V.

Bayenthalgürtel 23
50968 Cologne
Germany

German Research Foundation (DFG) eV

Kennedyallee 40
53175 Bonn
Germany

Industry

Dr.-Ing. Anton Stich
AUDI AG

RTD Performers

Overall Coordination of the Cluster Project:
Prof. Dr.-Ing. Erhard Leidich

SP I | Institute of Construction and Drive Technology (IKAT) | Chair of Engineering Design |TU Chemnitz

Head of Research:
Prof. Dr.-Ing. Erhard Leidich

Research Associate:
Matthias Gräfensteiner, M. Eng.

SP II | Institute of Production Metrology and Quality Assurance (IFMQ) | TU Chemnitz

Research Associates:
Dr.-Ing. Marko Gerlach
Dipl.-Ing. Saskia Schiefer

SP III | Institute of Machine Design (IMK) | Chair of Machine Elements and Tribology (LMT) | Otto-von-Guericke University Magdeburg (OVGU)

Head of Research:
Prof. Dr.-Ing. habil. Dirk Bartel

Research Associate:
Dipl.-Ing. Andreas Kießling

SP IV | Fraunhofer-Institute of Material and Beam Technology (IWS)

Research Associates:
Dr.-Ing. Otmar Zimmer
Dr. Volker Weihnacht

SP V | Laser Institute – University of Applied Sciences Mittweida (LHM)

Research Associate:
Dr. Jörg Schille

Research Association for Drive Technology (FVA) eV

Lyoner Strasse 18
60528 Frankfurt am Main
Germany

Fraunhofer-Gesellschaft

Institute of Material and Beam Technology (IWS)

Winterbergstrasse 28
01277 Dresden
Germany

Otto-von-Guericke-University Magdeburg (OVGU)

Institute of Machine Design (IMK)

Universitätsplatz 2
39106 Magdeburg
Germany

Technische Universität Chemnitz

Institute of Construction and Drive Technology (IKAT)/Chair of Engineering Design

Reichenhainer Strasse 70
09111 Chemnitz
Germany

Technische Universität Chemnitz

Institute of Machine Tools and Production Processes (IWP)/Chair of Production Metrology (FMT)

Reichenhainer Strasse 70
09126 Chemnitz
Germany

University of Applied Sciences Mittweida (HSMW)

Laser Institute (LMH)

Technikumplatz 17
09648 Mittweida
Germany

Deputy Managing Director

Martin Nitsche

FVV
+49 (0) 69 6603 1345
+49 (0) 69 6603 2345

Research Association for Combustion Engines eV

Lyoner Strasse 18
60528 Frankfurt am Main
Germany
T +49 69 6603 1345