Phenomenological friction model in deep drawing of aluminum sheet metals

International Deep Drawing Research Group 37th Annual Conference

Wiklund, Daniel^1 ; Larsson, Mats^2

Swerea IVF, Box 104, Mölndal

SE-431 22, Sweden^1

University West, Department of Production Processes, Trollhattan

SE-461 86, Sweden^2

关键词: Bending under tension tests;    Coulomb's frictions;    Forming simulations;    Inherent complexity;    Lubricant viscosity;    Micromechanical model;    Physical experiments;    Tribological systems;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/418/1/012097/pdf
DOI  :  10.1088/1757-899X/418/1/012097

来源: IOP

【 摘 要 】

Friction is an important parameter in sheet metal forming since it influences the flow of material in the process. Consequently, it is also an important parameter in the design process of new stamping dies when numerical simulations are utilized. Today, the most commonly used friction model in forming simulations is Coulomb's friction which is a strong simplification of the tribological system conditions and a contributory cause of discrepancy between simulation and physical experiments. There are micromechanical models available but with an inherent complexity that results in limited transparency for users. The objective in this study was to design a phenomenological friction model with a natural level of complexity when Coulomb's friction is inadequate. The local friction model considers implicit properties of tool and sheet surface topography, lubricant viscosity, sheet metal hardness and strain, and process parameters such as sliding speed and contact pressure. The model was calibrated in a Bending-Under-Tension test (BUT) and the performance was evaluated in a cross shaped geometry (X-die). The results show a significant improvement of the simulation precision and provide the user a transparent tribological system.