engleski

Effect of assymetric loads upon the spatial movement of open kinematic chains

As dynamic multibody systems having in their initial position one plane symmetry, are considered such systems in which the distributions of the members of the whole system, both in terms of their forms and in terms of their volumes of masses with respect to this plane, are identical. It results from such a definition that the symmetric movements of subsystems are those movements, which have the same geometrical and consequently, also dynamic characteristics with respect to the defined symmetry plane. In a general case, the symmetric distribution of masses is changed with respect to the selected symmetry plane, as well as to other reference planes, in the spatial movement of dynamic multibody systems. In numerous examples of resolving the geometry of movement of dynamic multibody systems, it is usual to select simplifications, which are usually reduced to observing the movement of systems as a movement in a plane. The elements of kinetic open chains that such propulsive dynamic multibody systems are composed of have appropriate spatial movements, both of translatory and of rotary types, which influence the changes in the central dynamic moments of slowness. In addition, the possible asymmetry of the position of the members during the movement of the system of open kinematics chains influences also the change in the shape of the path of the centre of the system masses by converting the plane curve into a spatial curve. Based upon the researches performed, it is possible to determine what is the greatness and what is the form of the effect of the change in the spatial curve as a function of the system propulsion rate. That fact is the reason for performing the researches on the possible influences of actual changes as compared to those occurring in the description of the movement in a plane.

open kinematic chains; multibody systems; human body movement

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