动力头及孔口板调转方向，可直接钻凿仰孔，大大增加钻孔倾角范围。

It can increase the hole inclination Angle range and drill elevation Angle holes, while setting the top drive power head and hole top plate toward the opposite direction.

youdao

对于有限尺寸板内开孔的情形，文中用有限单元法来分析腰圆形孔口的应力分布和应力集中。

For the plates with finite dimensions, the finite element method is used to obtain the stress distribution and stress concentration around the ovaloid opening.

youdao

板内有腰圆形孔口的情形在工程结构中经常会遇到。

Ovaloid openings in plates are often encountered in engineering structures.

youdao