Nodal Equations of Motion

 

The position of the node i is written as

 

                                               (1)

 

The velocity of the node i can be obtained by time differentiation of Eq. (2)

 

                                   (2)

 

The acceleration of the node i can be obtained by time differentiation of Eq. (3)

 

  (3)

 

The nodal equations of motion corresponding the node i can be derived as

 

    (4)

 

where,