ESTIMATION OF TRANSMISSION OF HAND PRESSURE FORCE THROUGH HUMAN BODY - EXPERIMENTAL INVESTIGATIONS

The experiments described in this article are part of the research leading to the development of a model, in which the man working with hand held percussive tool constitutes an active element of the system. Research had on purpose description of transmission of hand pressure force from hand tool, through human body to operator legs. During a new series of experiments, human operators stood on a horizontal platform and by exerting pressure on a tool's handle compared force realized by him with the sudden reference force. The human operator was considered as alive active element able to control the hand tool by exerting suitable pressure on the tool's handle to fulfill the task a priori defined. The used test stand allowed for the generation of reference force, measurement and visualization of the reference, and realized forces on the monitor's screen. Several variants of the experiments were registered and analyzed. Special attention was paid to transient and steady states of human reactions subjected to vibration excitation perturbations coming from the tool with chosen frequencies. Simultaneous recordings of exerting pressure force on a tool's handle and platform horizontal reaction allowed visualization of force transmission through the human body between hands and legs for the investigated participants in transient and steady, after realized control, states. As results of the studies functions describing the transmission of vibrations through the human body were received.