Dynamic Characteristics Of Human Body Research Articles

Dynamic Characteristics of Human Body at Jumping Motion by Bond graph

Dynamic Characteristics of Human Body at Jumping Motion by Bond graph

The Effects of Posture on Suspension Seat Transmissibility during Exposure to Vertical Whole-Body Vibration

Suspension seat is used in the off-road condition to attenuate excessive vibration exposed to the human body. The efficiency of a seat reducing vibration not only depends on the dynamic characteristics of the seat, but the dynamic characteristics of human body and the characteristics of the input vibration as well. Tractor drivers adopted different postures during their farm work activities, which may influence the dynamic characteristics of the human body. However, the influenced of the driver’s posture on suspension seat transmissibility has received less systematic attention. Thus, this study is carried out with the objective to investigate the effect of different postures on seat transmissibility when seated on a suspension seat. Three male subjects were exposed to random vibration at 2.0 m/s2 r.m.s with frequency ranging from 1-20 Hz, while seated on a vibration simulator for 60 seconds. The subjects adopted four seating postures: (i) relaxed, (ii) slouched, (iii) tensed and (iv) with backrest support. The study found that relaxed and slouched postures have a resonance frequency at 2.0 Hz. However, as the posture changed to backrest support, the resonance frequency of the seat transmissibility slightly increased by 0.25 Hz. This study suggested that changing the postures caused changes in the dynamics of human body, and thus affected the suspension seat transmissibility. It is concluded that, non-linearity in suspension seat transmissibility is influenced by the changes of body postures.

해상 근무 승무원의 수학적 전신진동 해석 모델에 관한 연구

The resonance behaviour needs be understood to identify the mechanisms responsible for the dynamic characteristics of human body, to allow for the non-linearity when predicting the influence of seating dynamics, and to predict the adverse effects caused by various magnitudes of vibration. However, there are currently no known studies on the effect of vibration magnitude on the transmissibility to thoracic or lumbar spine of the seated person, despite low back pain(LBP) being the most common ailment associated with whole-body vibration. The objective of this paper is to develop a proper mathematical human model for LBP and musculoskeletal injury of the crew in a maritime vehicle. In this study, 7 degree-of-freedom including 2 non-rigid mass representing wobbling visceral and intestine mass, is proposed. Also, when compared with previously published experimental results, the model response was found to be well-matching. When exposed to various of vertical vibration, the human model shows appreciable non-linearity in its biodynamic responses. The relationships of resonance for LBP and musculoskeletal injury during whole-body vibration are also explained.

조종 숙련도 변화에 따른 심리적 리스크 이미지의 변화에 대한 평가

The resonance behaviour needs be understood to identify the mechanisms responsible for the dynamic characteristics of human body, to allow for the non-linearity when predicting the influence of seating dynamics. and to predict the adverse effects caused by various magnitudes of vibration. However, there are currently no known studies on the effect of vibration magnitude on the transmissibility to thoracic or lumbar spine of the seated person. despite low back pain(LBP) being the most common ailment associated with whole-body vibration. The objective of this paper is to develop a proper mathematical human model for LBP and musculoskeletal injury of the crew in a maritime vehicle. In this study, 7 degree-of-freedom including 2 non-rigid mass representing wobbling visceral and intestine mass, is proposed. Also. when compared with previously published experimental results, the model response was found to be well-matching. When exposed to various of vertical vibration, the human model shows appreciable non-linearity in its biodynamic responses. The relationships of resonance for LBP and musculoskeletal injury during whole-body vibration are also explained.

Dynamics and Modelling of Human Body Exposed to Multidirectional Excitation. Dynamic Characteristics of Human Body Determined by Triaxial Vibration Test.

The purpose of this study is to investigate dynamic characteristics of the human body in a sitting position, by performing multidirectional excitation. Vibrational testing is performed using a three-axial shaking table on which a wooden seat is attached. Experiment participants sitting on the seat are subjected to excitation in three directions, i.e., fore-and-aft (x-axis), lateral (y-axis) and vertical (z-axis), in random order. The dynamics of the seated human body are characterized by transfer functions between the seat and the head. By measuring the vibration at the mouth and forehead, rotational transfer functions such as roll and pitch, as well as translational transfer functions, are obtained. In the results, two resonant peaks are observed between 0 Hz and 20 Hz in each translational direction. It is observed that the fore-and-aft motion and the vertical motion are coupled. It is experimentally confirmed that this dynamic coupling is caused by the pitch motion of the head.

Dynamic characteristics of human body exposed to the vibration of the vibrating tools

Dynamic characteristics of human body exposed to the vibration of the vibrating tools

On the characteristics of the self balancing function of Human body

This paper deals with the dynamic characteristics of Human body, that is, Human response in following step or sinusoidal input added to his body. We did the personality test as follows; (1) Transform the testee on the floor. (2) Shake the testee right-and-left or back-and-before. (3) Vibrate the testee up-and-down. (4) Decline the testee with bicycling style. And we measured the pursuit tracking at the near point of gravity of his body or another point. The aim of the tests is to put to use the reaults for no-man control of bicycling with robot. From these experiments, it was found that;(1) Balancing response of Human body is approximated to next formulas, that is, second order transfer function.(i) G(s)=B/s2+As+B(ii) G(s)=B/B/s2+As+B·e-TS(iii) G(s)=B/B/s2+As+B·(1-TS)(2) When the input freqwncy is lower than about 1.6c/s, the body tracks neary exactly with it, but higher than about 2.4c/s, the phase lag is exceeding.(3) Amplitude gain increases with input freqency for up-and-down vibration tests, but for right-and-left or back-and-before tests it degreeses with frequency, examply, about 10 to-40 dB.

Dynamic Characteristics of Human Body in Three Dimensional Ballistocardiography

Dynamic Characteristics of Human Body in Three Dimensional Ballistocardiography