Rigid Link

A rigid link imposes the same velocity on all secondary nodes in one or more directions. The directions are defined to a skew or global frame. 図 1 displays a rigid link.

The velocity of the group of nodes rigidly linked together is computed using momentum conservation (Section Definition, 式 1). However, no global moment equilibrium is respected.

$$V^i=\frac{{\displaystyle \sum _{i=i}^N{m}_i{v}_i}}{{\displaystyle \sum _{i=i}^N{m}_i}}$$

Angular velocity for the i^th DOF with respect to the global or a skew reference frame is:

$${\omega }^i=\frac{\left({\displaystyle \sum _{j=1}^n{I}_j^i{\omega }_j^i}\right)}{\left({\displaystyle \sum _{j=1}^N{I}_j^i}\right)}$$