Rod strings are designed by computing compound stress with the fourth strength energy on the condition of torque and axial force.

应用第四强度理论，求解杆柱在扭矩和轴向力条件下的复合应力，设计抽油杆柱。

youdao

When the shrinkage of the rod fracture surface much more than that of the cup part fracture surface, its formation by compound extrusion is not applicable.

当杆的断面收缩率比杯形部分断面收缩率大得较多时，不适合直接用复合挤压成形。

youdao

The new developing carbon fiber compound flexible coiled rod overcome the shortcoming of ordinary steel rod, can meet the need of low permeability oilfield production.

新开发研制的碳纤维复合柔性连续抽油杆克服了普通钢杆的缺点，能够满足低渗油田小泵深抽技术的要求。

youdao