I had to bend double to get under the table.

我必须弓着身子才能钻到桌子底下。

There's a double bend of the body.

有一个身体的双倍的弯曲处。

According to double radius method and edge bend method, this paper introduces the design theory of roll pass with opposite direction bend in middle part for cold forming of round pipe.

本文在双半径法和边缘弯曲法的基础上，介绍了一种冷弯圆管的中部反向弯曲孔型设计理论。