Experimental Assessment of Friction Coefficient in Deep Drawing and Its Verification by Numerical Simulation

Abstract

The friction coefficient in the simulation of stamping processes should be defined. Modern simulation software allows its definition as constant or its dependence on pressure or temperature. It is also useful in stamping processes to define different values in different regions, as it often reflects the nature of deformation process. This article deals with the regression and analytical models commonly used to determine the friction coefficients in specified areas of the stamping process. Analytical models were verified by an experimental strip drawing test under the same contact conditions. Steel sheets for the automotive industry were used in experiments and simulations—extra deep drawing quality DC 05 and austenitic stainless steel AISI 304. Friction coefficients were also evaluated when the cup test was performed. A regression model of drawing to the blankholding force was applied to the results. Conformity of friction coefficients when measured by cup tests and strip tests was confirmed. The values of the friction coefficient reached from the experiment were applied in FEM simulation software.

Design of a Tribo-Simulator for Investigation of the Tribological Behavior of Stainless-Steel Sheets Under Different Contact Conditions

“…The difference between the initial surface roughness values (Ra) also may be contributed to the lower COF of the AISI 304 steel in the BUT test because its initial roughness was, on average, approximately 48% higher than that of the AISI 430 steel (Table 5). Evin et al 6 explained that on a very smooth surface, the lubricant is not well-retained on the contact surfaces during the drawing of the strip. As a result, cold welds form between the sheet surface and the tool even at low pressures and short paths of drawing.…”

“…Trzepiecinski 2 noted that the mechanical properties of the metallic sheet are an important factor, and inadequate consideration of this factor in the design of SMF manufacturing processes causes buckling, excessive thinning, tearing, and wrinkling of the components. However, an extensive amount of research has listed several other factors that affect the final shape of the components, such as the geometry of the tool (e.g., punch-to-die clearance and die and punch radii), technological parameters (e.g., temperature and forming speed), properties of the tool material (e.g., hardness and chemical composition), and friction conditions or contact (e.g., dry or lubricated contact, lubricant type, contact pressure, initial surface topography, and geometry and kinematics of tribocontact) [1][2][3][4][5][6][7][8][9] .…”

A Novel Method for Friction Coefficient Calculation in Metal Sheet Forming of Axis-Symmetric Deep Drawing Parts

“…There has been little progress on modeling of friction in sheet metal plastic forming in the past years, because there are too many unknowns in the friction mechanism and friction process in the stamping process. The dynamic friction process in the stamping process is very complex [3]. Many research efforts have been made.…”

Polynomial Multiple Regression Analysis of the Lubrication Effectiveness of Deep Drawing Quality Steel Sheets by Eco-Friendly Vegetable Oils

“…The main factors influencing the tribological phenomena in SMF processes are, among others, the kinematics of the tool movement, the character of the loads (static and dynamic contact), the micro- and macro-geometry of the contact, the physicochemical phenomena on the contact surface and the temperature [ 4 , 5 ]. Friction in SMF processes is a complex function of the process parameters, the surface topography of the sheet to be formed and the tools, and the contact conditions that are constantly evolving in various regions of the drawpiece [ 6 ].…”