Friction in Sheet Metal Forming Simulations: Modelling of New Sheet Metal Coatings and Lubricants

International Deep Drawing Research Group 37th Annual Conference

Sigvant, M.^1,2 ; Pilthammar, J.^1,2 ; Hol, J.^3 ; Wiebenga, J.H.^3 ; Chezan, T.^4 ; Carleer, B.^5 ; Van Den Boogaard, A.H.^6

Volvo Cars, Dept 81153 Stamping CAE and Die Development, Olofström, Sweden^1

Blekinge Institute of Technology, Valhallavagen, Karlskrona

371 41, Sweden^2

TriboForm Engineering, Hengelosestraat 500, AN Enschede

7521, Netherlands^3

Tata Steel, P.O. Box 10.000, CA IJmuiden

1970, Netherlands^4

AutoForm Engineering, Josep-v-Fraunhofer Str. 13A, Dortmund

D-44227, Germany^5

University of Twente, P.O. Box 217, Enschede

7500 AE, Netherlands^6

关键词: Coefficient of frictions;    Forming simulations;    Friction conditions;    Friction modelling;    Industrial standards;    Prediction accuracy;    Simulation accuracy;    University of Twente;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/418/1/012093/pdf
DOI  :  10.1088/1757-899X/418/1/012093

来源: IOP

【 摘 要 】

The quality of sheet metal formed parts is strongly dependent on the tribology and friction conditions that are acting in the actual forming process. These friction conditions are then dependent on the tribology system, i.e. the applied sheet material, coating and tooling material, the lubrication and process conditions. Although friction is of key importance, it is currently not considered in detail in sheet metal forming simulations. The current industrial standard is to use a constant (Coulomb) coefficient of friction, which limits the overall simulation accuracy. Since a few years back there is an ongoing collaboration on friction modelling between Volvo Cars, Tata Steel, TriboForm Engineering, AutoForm Engineering and the University of Twente. In previous papers by the authors, results from lab scale studies and studies of a door-inner part in Volvo Cars production have been presented. This paper focuses on the tribology conditions during early tryout of dies for new car models with an emphasis on the effect of the usage of new steel material coatings and lubricants on forming results. The motivation for the study is that the majority of the forming simulations at Volvo Cars are performed to secure the die tryout, i.e. solve as many problems as possible in forming simulations before the final design of the die and milling of the casting. In the current study, three closure parts for the new Volvo V60 model have been analysed with both Coulomb and TriboForm friction models. The simulation results from the different friction models are compared using thickness measurements of real parts, and 3D geometry scanning data of the parts. Results show the improved prediction accuracy of forming simulations when using the TriboForm friction model, demonstrating the ability to account for the effect of new sheet metal coatings and lubricants in sheet metal forming simulations.