The formulas of drawing force for spiral internal-ribbedpipe cold-drawing are derived with upperbound method.
利用上界法推导了冷拔内螺旋凸筋管拔制力计算式。
2
The experiment result shows that the theoretical values are close to those measured, which provides a theoretical basis for internal-ribbedpipe cold-drawing equipment type selecting.
实验表明，理论计算值与实测值较吻合，可为冷拔内螺旋凸筋管的拔制设备选型提供理论依据。
3
The main reinforcing rib is protected against being destroyed in the processing and applying process, thereby enhancing the ring stiffness of a straight ribbedpipe wound by glass-reinforced plastics.