Yoshikiyo Tamai

A Study of Topology Optimization for Joint Locations of Automotive Full Vehicle

The optimization method for searching the joint locations of spot-welding and adhesives in a automotive body made of steel sheets was studied [1]. The key point is that the topology optimization method was applied to the optimization of joint elements by using a full vehicle model in order to improve vehicle performance. In addition to static stiffness using constraints, stiffness while driving is required in the body stiffness of the full vehicle. Inertia relief is known as a method for expression of behavior while driving.

Frictional Behavior of Steel Sheets in Press Forming and Optimization of Friction Testing Conditions

The typical sliding conditions at the fracture-risk positions in press forming of automotive parts were identified by FE analysis and laboratory-scale sliding tests. The investigated sliding conditions fall into three categories: the inflow sections of a steel sheet (group A), the punch shoulders in drawing (group B), and the stretch sections (group C). The frictional properties of group A and group B could be evaluated by measurement of the dynamic coefficient of friction in the flat sliding tests under a high contact pressure and at low sliding speed in each group area. The frictional properties of group C could be evaluated by the static coefficient of friction, which is measured as the primary peak in a coefficient of friction – stroke curve under the specific sliding test conditions (contact pressure: 7MPa, sliding speed: 10mm/min, tool length: 10mm).