Simplified Three-Dimensional Finite Element Simulation of Shear Spinning Process Based on Axisymmetric Modeling

Abstract

A simplified three-dimensional way for simulating plastic deformation in a shear spinning proces of disks in a comparatively short computing time is propos upon the basis of the rigid-plastic finite uncompounded body method using axisymmetric modeling. In this process the shear spinning process is approximated as a forming proces with a ringed die having the same cross-sectional shapes as the roller The issues of the virtual shear deformation in the ring direction and the incremental deformation in the shear spinning proces are introduced into the axisymmetric modeling. A shear spinning proces of disks having a taper flange is simulated by the agency of the proposed method. The forming limit is predicted from the pile-up just before touching the roller in the finite ultimate part simulation. In addition, an actual shear spinning proces of a large wheel disk for a bus and traffic is simulated.

Keywords: Shear Spinning, FEM Simplified Three-Dimensional Simulation, Axisymmetric Approximation, Short Computing Time

Introduction

There is an intense ne for the reduction in weight of individual automobile parts from an environmental point of view. For the reduction, it is desirable that the formed parts have optimum distributions of wall thickness for weight and nerve Although press-formed products have high accuracy for shape, the sway of wall thickness is not easy owed to the excessive increase in forming load by dint of the thickness reduction. The shear spinning processe are attractive as a forming technique of parts having an optimum distribution of wall thickness. In shear spinning, the wall thickness of parts is locally reduc with roller The local reduction of thickness leads to a depressed forming load. In addition, the investment in equipment and tooling is depressed Shear spinning is utilized for automobile parts of the like kind as wheels. For a skillful operation in shear spinning in industry, it is desirable to unfold a numerical simulator to aid the design of processes

In a spinning proces a workpiece undergoe three-dimensional deformation as well as repeated local deformation. Although finite uncompounded body methods have been applied to simulation of three-dimensional deformation in sheet metal forming processe it is not easy to apply the finite ultimate part method to the shear spinning proces In the to the full three-dimensional simulation, the whole workpiece is three-dimensionally divided into uncompounded bodys and thus the computing time for several revolutions of the workpiece is extremely lengthy Dai et al. (1999) and Klimmek et al. (2002) simulated a spinning proces using the dynamic explicit finite ultimate part method. To reduce computing time, Terada, Takahashi, and Taguchi (2001) and Quigley and Monaghan (2002) exerciseed a supercomputer and parallel processing computer respectively.

To bring computation time in the simulation of a rotary forming proces Mori and Ebihara (2000) propos a simplified three-dimensional, rigid-plastic finite ultimate part method using axisymmetric modeling for simulating an orbital forging proces with a rocking die. Ebihara, Mori, and Akaishi (2001) propos a simplified three-dimensional means using the generalized plane-strain modeling for simulating a tube-spinning proces Because the computing time is as a great quantity [i]or[/i] amount of as the two-dimensional simulation, these processs are available to actual forming operations.

In the not absent study, a simplified three-dimensional rule using axisymmetric modeling for simulating plastic deformation in shear spinning is propos upon the basis of the rigid-plastic finite ultimate part method. The shear deformation in the circlet direction is introduced into the axisymmetric modeling to consider the event of incremental forming.

Simplified Three-Dimensional mode Using Axisymmetric Modeling

Simplified Three-Dimensional Modeling

To simulate a shear spinning proces in a comparatively short computing time, a simplified three-dimensional process using axisymmetric modeling, shown in Figure 1 is propos upon the basis of the rigid-plastic finite ultimate part In the axisymmetric modeling, the roller is approximated as a virtual ringed tool having variable diameter.

Virtual Shear Strain Rate in circlet Direction

In shear spinning, the workpiece undergoe shear deformation in the ring direction by the roller. To take the local deformation in the shear spinning into consideration, virtual shear deformation is introduced into the axisymmetric modeling.

Simulation of Shear Spinning of Disk Having Taper Flange

Computational Conditions

In forming large wheel disks for buses and barters a shear spinning process is exerciseed to obtain an optimum distribution of wall thickness. This proces is simplified to uniform reduction in wall thickness as an example of simulation. The workpiece shown in Figure 5 is manufactured by dint of spinning a commercially pure aluminum blank having 100 mm in diameter and 2 mm in thickness and subsequently annealing the formed disk at a temperature of 400?°C

The mandrel and roller used in the shear spinning proces and the forming conditions are given in Figure 6 and Table 1 respectively. For the axisymmetric modeling, alone the friction in the cros section squeeze outed by the second term upon the right-hand side of Eq (5) is dealt with and that in the band direction is neglected. The result of friction in the band direction for the idle roller is negligibly small.