A method to model mechanical systems with multibond graphs is described. The method is based on the description of the vector velocity relation of a moving point in a rotating system. This relation is incorporated in a bond graph. Since bond graphs are based on the power conserving concept, theforce or momenta relations are then available too. By repeating the same bond graph structurefor every point (which is of interest within a chosen coordinateframe), where each point has the same rotational velocity, a systematic way of modelling mechanical systems is achieved. It is explained how connected mechanical linkages have to be handled. Two simple examples are given. Nomenclature % ki P., F; Aj,i x(xb, j) mi Ji R C
column matrix with the angular velocities of body k, with regard to body 1, in coordinates of coordinate system i. The subscript 1 is dropped when 1 = 0 column matrix with the velocity of point p in coordinates of system i, measured with respect to the system j. When j = 0, j is dropped. column matrix with the force acting on p in coordinates of system i coordinate transformation matrix to transform coordinates from system i to j transformation matrix giving the linear velocity of point p with respect to j, due to rotation of system i, in coordinates of system i diagonal matrix with the mass of body i inertia matrix of body i, related to the body fixed system i dissipator compliance
The underlined characters in the figures are equivalent to the bold face characters, representing a matrix.