scholarly journals Biodynamics of supine humans and interaction with transport systems during vibration and shocks

2017 ◽  
Vol 38 (2) ◽  
pp. 808-816 ◽  
Author(s):  
Salam Rahmatalla ◽  
Jonathan DeShaw ◽  
Khalid Barazanji
Keyword(s):  
Relative Motion ◽  
Random Vibration ◽  
Whole Body Vibration ◽  
Three Dimensional ◽  
Whole Body ◽  
Transport Systems ◽  
Biomechanical Response ◽  
Contact Surfaces ◽  
Vertical Accelerations ◽  
Human Transport

This work investigates the effect of the contact surfaces on the biomechanical response of supine humans during whole-body vibration and shocks. Twelve participants were exposed to three-dimensional random vibration and shocks and were tested with two types of contact surfaces: (i) litter only, and (ii) litter with spinal board. The two configurations were tested with and without body straps to secure the supine human. The addition of the spinal board reduced the involuntary motion of the supine humans in most directions. There were significant reductions in the relative vertical accelerations at the neck and torso areas, especially during shocks ( p < 0.01). The inclusion of body straps with the spinal board was more effective in reducing the relative motion in most directions when shocks were presented. This study shows that the ergonomic design of the human transport system and the underlying contacting surfaces should be studied during dynamic transport environments.

Three-Dimensional Modeling of Supine Human and Transport System Under Whole-Body Vibration

2013 ◽  
Vol 135 (6) ◽  
Author(s):  
Yang Wang ◽  
Salam Rahmatalla
Keyword(s):  
Dynamic Model ◽  
Transport System ◽  
Vibration Suppression ◽  
Whole Body Vibration ◽  
Three Dimensional ◽  
Vertical Direction ◽  
Human Model ◽  
Whole Body ◽  
Transport Systems ◽  
Body Vibration

The development of predictive computer human models in whole-body vibration has shown some success in predicting simple types of motion, mostly for seated positions and in the uniaxial vertical direction. The literature revealed only a handful of papers that tackled supine human modeling in response to vertical vibration. The objective of this work is to develop a predictive, multibody, three-dimensional human model to simulate the supine human and underlying transport system in response to multidirectional whole-body vibration. A three-dimensional dynamic model of a supine human and its underlying transport system is presented in this work to predict supine-human biodynamic response under three-dimensional input random whole-body vibration. The proposed supine-human model consists of three interconnected segments representing the head, torso-arms, and pelvis-legs. The segments are connected via rotational and translational joints that have spring-damper components simulating the three-dimensional muscles and tissuelike connecting elements in the three x, y, and z directions. Two types of transport systems are considered in this work, a rigid support and a long spinal board attached to a standard military litter. The contact surfaces between the supine human and the underlying transport system are modeled using spring-damper components. Eight healthy supine human subjects were tested under combined-axis vibration files with a magnitude of 0.5 m/s2 (rms) and a frequency content of 0.5–16 Hz. The data from seven subjects were used in parameter identification for the dynamic model using optimization schemes in the frequency domain that minimize the differences between the magnitude and phase of the predicted and experimental transmissibility. The predicted accelerations in the time and frequency domains were comparable to those gathered from experiments under different anthropometric, input vibration, and transport conditions under investigation. Based on the results, the proposed dynamic model has the potential to be used to provide motion data to drive a detailed finite element model of a supine human for further investigation of muscle forces and joint dynamics. The predicted kinematics of the supine human and transport system would also benefit patient safety planners and vibration suppression designers in their endeavors.

scholarly journals WHOLE BODY AND HAND-ARM VIBRATIONS ON OFF-ROAD VEHICLE USED IN ACADEMICALS COMPETITIONS

2017 ◽  
Vol 24 (5) ◽  
pp. 375-382
Author(s):  
Fábio Celso Oliveira ◽  
Geice Paula Villibor ◽  
Joseph Kalil Khoury Junior ◽  
Éder Harisson Ferreira Lima
Keyword(s):  
Whole Body Vibration ◽  
Whole Body ◽  
Vibration Exposure ◽  
Military Operations ◽  
Road Vehicles ◽  
Body Vibration ◽  
Acceleration Level ◽  
Vertical Accelerations ◽  
Warning Limits ◽  
Iso 2631

Off-road vehicles, baja type, are designed for locomotion on irregular terrains with several obstacles, to pull loads with effciency, furthermore, are compact and easy to operate. Such vehicles have wide use in agriculture, construction, transportation and military operations. Baja vehicle provide to pilot an exposure to high levels of mechanical vibrations. With the present work aimed to determine the whole body vibration and hand-arm vibration in the pilot using the vehicle designed by UFVbaja team. The vibrations levels incident on the pilot was measured in three different terrain conditions and different forward speeds. It was determinate the root mean square acceleration and daily vibration exposure at the seat pad and hand-arm of pilot. For whole body vibration was obtained the daily vibration dose value. The values were confronted with standards ISO 2631-1. The acceleration level, normalized to 8 hour, exceeded the warning limits for all worked conditions. To Baja vehicle operating in plowing soil, the transverse and vertical accelerations exceeded the limit level. In general, incident acceleration levels on the pilot were considered high, which reinforces the need for seats projects of suspension, steering and seat that effectively reduce the vibration transmitted to pilot body and hand-arm system.

Three-dimensional motion capture protocol for seated operator in whole body vibration

2008 ◽  
Vol 38 (5-6) ◽  
pp. 425-433 ◽  
Author(s):  
S. Rahmatalla ◽  
T. Xia ◽  
M. Contratto ◽  
G. Kopp ◽  
D. Wilder ◽  
...  
Keyword(s):  
Motion Capture ◽  
Whole Body Vibration ◽  
Three Dimensional ◽  
Whole Body ◽  
Body Vibration
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