st52-3G铁基板材成形过程中变形的有限元模拟

Finite element simulation of deformation in forming process of st52-3G ironbased plate

st52-3G铁基板材冷弯成形过程是复杂的变形过程,对孔型设计依赖较大,孔型稍不合适就出现缺陷。采用有限元法对st52-3G铁基板材在不同角度下的冷弯成形过程进行有限元数值模拟,分析成形过程中变形区金属的应力变化规律和变形分布情况。结果表明:在坯料厚度方向,中性层内侧金属压缩变形,外侧金属拉伸变形,此方向变形不均是导致长度方向变形不均的根源,也是板型不良的根源;弯曲角度超过[25°]时,变形不均性开始增大;弯曲角度在26~29[(°)时,变形不均性随着变形角度的增大而快速增大,但并未出现板型不良;弯曲角度在[30°]时,变形不均匀异常剧烈,并开始出现板型不良;孔型设计时可适当增大冷弯角度,但不能过大,过大易导致板形缺陷,合适的冷弯角度为25~29[(°)。

The cold bending process of st52-3G iron-based sheet metal is a complicated deformation process, which depends heavily on pass design, and defects appear when the pass is slightly inappropriate. Finite element method was used to simulate the cold bending process of st52-3G iron-based sheet at different angles. The stress variation law and deformation distribution of metal in deformation zone were analyzed. Results show that in the direction of thickness, the inner metal of neutral layer is compressed, and the lateral metal is stretched, which is the source of non-uniform deformation of the longitudinal direction, and also the cause of the defective plate. When the bending angle is more than[25°], non-uniform deformation begins to increase rapidly. The non-uniformity of deformation increases rapidly with the bending angle in 26-29[(°)], but the defective plate does not appear. When thebending angle is [30°], uneven deformation is extremely serious, and defective plate appears. The cold bending angle can be appropriately increased, but too large angle leads to flatness defect. The suitable angle for cold bending is 25-29[(°)].