平面汇交力系
plane converging system of forces
plane concurrent force system
超平面系数
coefficients of critical hyper-plane
承压平面平衡
parting surface support balance
单一平面平衡机
single-plane (static) balancing machine
非定常平面平行运动
unsteady planar parallel flow
刚体平面平行运动
plane motion of rigid body