双相钢板成形界面压力数值仿真及对板料表面损伤影响

Numerical Analysis for Contact Pressure and Surface Damage in Dual-phase Steel Sheet Stamping

借助于有限元软件建立弯曲过程接触界面压力的仿真计算模型,并用于计算双相钢与模具接触界面的压力.结果表明,在整个冲压行程中,板料上界面的压力分布可分为瞬态阶段和稳态阶段.在瞬态阶段,板料上界面压力的分布不连续并存在2个明显的峰值,其界面压力峰值显著高于稳态阶段;在稳态阶段,板料上界面压力的分布均匀连续,分为高压力区和低压力区,板料刚流入凹模圆角处的界面压力大于流出凹模圆角处的界面压力.钢板强度和成形压边力影响稳态阶段的界面压力和接触区域宽度,且呈现出正比例变化关系,从而对钢板表面的损伤带来不利影响.

In order to obtain the evolution law of contact pressure between blank and tool interfaces in sheet metal forming, the numerical simulation model of a channel forming process was developed based on the fi- nite element software ABAQUS. It was found from the numerical calculation that the contact pressure is comprised of an initial transient response and a steady phase in the duration of the forming process. While the contact pressure is continuous in steady-state and can be divided into a high contact pressure zone and a low contact pressure zone, the contact pressure in transient phase is discontinuous and is characterized by a two-peak contact pressure. The numerical results show the peak contact pressure in transient phase is much higher than that in steady phase, and the contact pressure on the blank at the start of die radius is higher than that at the end in steady phase. Furthermore, a parametric study was conducted. It was found that the steel strength has a positive proportion effect on the contact pressure, and the contact area increa- ses with the increasing of the blank holder force.