Kepler's 3rd law for circular orbits; Building up the shell-force by integration; Springgun.
开普勒圆周轨道第三定律；利用积分推导球壳的引力；弹簧。
2
Used as a fatigue failure criterion, application of the model to the fatigue life prediction for the feeding spring of a medium calibre automatic naval gun proved to be comparatively satisfactory.
对数累积损伤模型作为—个失效判据，已在某中口径自动舰炮输弹簧的疲劳寿命预测中得到较满意的应用。
3
Reliability design theory with variety of failure mode is put forth to design gun brake spring concerning the fact that there are often defects in gun brake springs.