Absorbed power distribution in the whole-body system of a tractor operator
More details
Hide details
Industrial Institute of Agricultural Engineering, Poznań, Poland
University of Life Sciences, Lublin, Poland
Department of Health Sciences, University of Medical Sciences, Poznań, Poland
University of Technology, Lublin, Poland
Warsaw University of Technology, Poland
Corresponding author
Mariusz Szymanek   

University of Life Sciences, Lublin, Poland
Ann Agric Environ Med. 2016;23(2):373-376
Introduction and objective:
Many people are exposed to vibration (WBV) in their occupational lives. The biodynamic responses of the human body in sitting conditions have been widely measured under whole-body vibration (WBV). The measures are most often expressed in terms of force-motion relations at the driving-point, namely, mechanical impedance, apparent mass and absorbed power, and flow of vibration through the body, such as seat-to-head and body segments vibration transmissibility. The absorbed power is a measure of the energy absorbed by the subject due to the external forces applied to the system.

Material and Methods:
The body behaves like a vibrating physical system with distributed energy-storage elements (masses, springs) and energy-dissipation elements (dampers). The total quantity of power can be divided into 2 components – one real and one imaginary. The real component reflects the energy-absorbing part of the system, due to the transformation of friction into heat within the tissues. The imaginary component reflects the energy-storing part of the system which does not consume any vibration energy.

The seated human is modeled as a series 4-DOF dynamic models. After introduction of the excitation, the response in particular segments of the model can be analyzed. As an example, the vibration power dissipated in an operator’s body segments has been determined as a function of the agricultural combination operating speed 1.4 – 2.75 ms-1.

The concept of absorbed power as a measurement for evaluation of WBV exposure opens a new area for research. The important character of absorbed power is that it has physical significance and therefore can be measured as well as computed analytically. The absorbed power relates to dissipation of energy attributed to relative motions of the visco-elastic tissues, muscles and skeletal system, which under prolonged exposures could lead to physical damage in the musculoskeletal system. A structural model of the human operator allows determination of the dynamic characteristics of the model, and study of the energy flow between the elements of the model.

Cieślikowski B. Modelling of the vibration damping in an operator’s seat system. TEKA Kom Mot Energ Roln. OL PAN. 2009; 9: 24–31.
Juliszewski T. Badania zmienności drgań mechanicznych siodeł i poziomu dźwięku jako ergonomicznych parametrów ciągników rolniczych. (The variability in mechanical vibrations of seats and in noise levels as ergonomic parameters of farm tractors). Zeszyty Naukowe Akademii Rolniczej w Krakowie. Rozprawy nr 197. 1995.
ISO 5982 (1981): Vibration and shock – mechanical driving point impedance of the human body.
Liang CC, Chiang CF. A study on biodynamic models of seated human subjects exposed to vertical vibration. Int J Ind Ergon. 2006; 36: 869–890.
Wael Abbas, Ossama B, Abouelatta. Magdy S, El-Azab. Adel A, Megahed. Application of Genetic Algorithms to the Optimal Design of Vehicle’s Driver-Seat Suspension Model. Proceedings of the World Congress on Engineering (London. U.K.. June 30 – July 2. 2010).2010; p 1630–1635.
Szczepaniak J, Kromulski J. Analysis of energy flow model in the biomechanical system human operator – agricultural combination. J Res Appl Agric Eng. 2011; 56(4): 138–142.
Szczepaniak J, Tanaś W, Pawłowski T, Kromulski J. Modeling of agricultural combination driver behaviour in aspect of safety of movement. Ann Agric Environ Med. 2014; 21(2): 403–406.
Szczepaniak J, Kromulski J, Dudziak B. Dynamic loads acting on the farm tractor operator at work in the field with the increased operating speed. Combustion Engines. 2013; 154(3): 981–984.
Lundström R, Homlund P. Absorption of energy during whole-body vibration exposure. J Sound Vib. 1998; 215(4): 789–799.
Szczepaniak J, Tanaś W, Kromulski J. Vibration energy absorption in the hole-body system of tractor operator. Ann Agric Environ Med. 2014; 21(2): 399–402.
Xie X. Absorbed power as a measure of whole body vehicular vibration exposure. Department of Mechanical Engineering. Concordia University Montreal. Quebec. Canada. 2001.
Nawayseh N, Griffin MJ. Power absorbed during whole-body vertical vibration: Effects of sitting posture. backrest. and foot rest. J Sound Vib. 2010; 329: 2928–2938.
Tajanowskij G, Tanas W. The analysis of regular wheel loadings distribution at a statically unstable running system if an agricultural machine on rough surface. Teka commission of motorization and power industry in agriculture. 2010; Polish Academy of sciences branch in Lublin. Vol. X. 464–474.
Rakheja S, Mandapuram S, Dong RG. Energy Absorption of Seated Occupants Exposed to Horizontal Vibration and Role of Back Support Condition. Industrial Health. 2008; 550–566.
ISO 2631–1. 1997. Mechanical Vibration and Shock e Evaluation of Human Exposure to Whole Body Vibration. Part 1: General Requirements. International Standards Organization. Switzerland.
Woodhouse. J. Linear damping models for structural vibration. J Sound Vib. 1998; 215(3): 547–569.
Journals System - logo
Scroll to top