针对型材三维成形易出现的凹陷、凸起等截面变形问题，在自主研发的拉弯成形 装置基础上，选取矩形管状铝合金型材进行了多点柔性成形制件的形状误差研究，分析了 制件横截面高度、宽度方向的变形沿制件长度方向的变化． 结果表明: 成形过程中，矩形管 材制件的上、下表面发生内凹变形，随着制件由对称中心点向两侧对称长度的增加，凹陷 率和内凹变形均增大，且上表面的内凹值略大于下表面内凹值; 成形过程中，制件的内、外 垂直表面出现外凸变形，并且随着对称中心点向两侧对称长度的增加，凸胀率和外凸变形 量更大．

Ｒeferring to the section deformation problem of 3D stretch bending profile，the shape deviation and influential factors of section deformation for multi-point flexible 3D stretch bending profile is investigated on the basis of the independent developed equipment; and the effect of part axial length on part cross section height /width deformation is analyzed． The experiment result shows that，on the upper/lower surface of rectangular tube part，both the concave percentage and concave deformation of part emerged and rose with the increased length from the bending symmetric center point to two sides along with axial direction，the concave deformation value on upper surface is bigger than that of lower surface; both the convex percentage and convex deformation emerged on the inside and outside vertical surface，and the convex percentage and convex deformation value rose with the increased length from the bending symmetric central point to two sides along with axial direction．