Identification and Experimental Validation of Damping Ratios of Different Human Body Segments Through Anthropometric Vibratory Model in Standing Posture

2006 ◽  
Vol 129 (4) ◽  
pp. 566-574 ◽  
Author(s):  
T. C. Gupta
Keyword(s):  
Human Body ◽  
Damping Ratio ◽  
Physical Structure ◽  
The Body ◽  
Anthropometric Data ◽  
Body Segments ◽  
Lumped Parameter ◽  
Mass Damper ◽  
Linear Spring ◽  
Experimental Response

A 15degrees of freedom lumped parameter vibratory model of human body is developed, for vertical mode vibrations, using anthropometric data of the 50th percentile US male. The mass and stiffness of various segments are determined from the elastic modulii of bones and tissues and from the anthropometric data available, assuming the shape of all the segments is ellipsoidal. The damping ratio of each segment is estimated on the basis of the physical structure of the body in a particular posture. Damping constants of various segments are calculated from these damping ratios. The human body is modeled as a linear spring-mass-damper system. The optimal values of the damping ratios of the body segments are estimated, for the 15degrees of freedom model of the 50th percentile US male, by comparing the response of the model with the experimental response. Formulating a similar vibratory model of the 50th percentile Indian male and comparing the frequency response of the model with the experimental response of the same group of subjects validate the modeling procedure. A range of damping ratios has been considered to develop a vibratory model, which can predict the vertical harmonic response of the human body.

A Comparative Study of the Forces Acting on a Human Rider on a Motorcycle for Different Impact Configurations

2012 ◽  
Author(s):  
Nikhil J. Dhinagar
Keyword(s):  
Human Body ◽  
Energy Content ◽  
Head Injuries ◽  
Preventive Measure ◽  
The Body ◽  
Body Segments ◽  
Injury Criteria ◽  
Male Model ◽  
Full Face ◽  
Motorcycle Crashes

In many parts of the developing countries powered motorcycles are still a primary mode of commutation. Statistics tells us that around 15–20% of the accidents happening across different countries in the world involve motorcycle crashes. With the increased importance placed on the usage of safety helmets or full face helmets by the motorbike riders, head injuries have significantly reduced as compared to the other extremities of the human body. The different segments of the human male model considered for this research are grouped into four main categories, the head and neck, the upper extremities, the lower extremities and the trunk. The center of gravity differs for different segments of the human body as each segment has its own mass. This study aims to form a comprehensive database of the forces acting on the primary human body segments for three accident configurations. The energy content of each of these segments is calculated. The deceleration of the human body after impact of the bike with the obstacle and the distance it travels before reaching zero velocity is also computed. When coupled with the existing knowledge of the injury criteria and biomechanical tolerance limits for the body segments, this can be used in a versatile way to predict injuries that could possibly occur in a bike accident and automate vehicle dynamic controls as a preventive measure. Forces calculated acting on the various human body segments can be used to suitably develop riding protection gear for commercial purposes.

Analysis and modeling of human seat interaction with a focus on the upper body and backrest using biomechanics and contact mechanics

Work ◽  
2021 ◽  
Vol 68 (s1) ◽  
pp. S161-S182
Author(s):  
Yuezhi (Sean) Liu ◽  
Xianzhi Zhong ◽  
Wintta Ghebreiyesus ◽  
Jiancheng Ji ◽  
Fengfeng (Jeff) Xi
Keyword(s):  
Human Body ◽  
The Body ◽  
Contact Forces ◽  
Human Anatomy ◽  
Upper Body ◽  
Stress Theory ◽  
Body Segments ◽  
Seat Comfort ◽  
Muscular Structure ◽  
Point Forces

BACKGROUND: This paper outlines a method to study the interaction between the human body and the aircraft seat concerning the seat comfort. METHOD: Firstly, the human body is modeled based on biomechanics and divided into a number of body segments connected by joints according to human anatomy. The angles between the body segments are obtained by curve fitting of the existing biomechanical research data. The contact forces between the human body and the seat are modeled using pairs of bi-lateral point forces. These forces are calculated and located through the analysis of the center of gravity of each body segment and average muscular structure of the human body. The geometry of the human and the seat is obtained from a 3D scan model or a CAD model. Secondly, the pressure distribution between the human body and the seat is modeled and calculated using the contact stress theory. The results of the two parts are combined to analyze the comfortability in relation to different postures, backrest recline angles and changing in shape and material. RESULTS: Simulations were performed and they are compared with experimental measurement and various FEM studies for validation. It is found that accuracy of this method is comparable with most FEM calculation. CONCLUSION: This method provides a new direction in cushion conform research. It is faster and convenient to use comparing to the FEM, and the result is reliable.

Modal Damping Ratio and Optimal Elastic Moduli of Human Body Segments for Anthropometric Vibratory Model of Standing Subjects

2017 ◽  
Vol 139 (10) ◽  
Author(s):  
Manoj Gupta ◽  
T. C. Gupta
Keyword(s):  
Dynamic Response ◽  
Human Body ◽  
Elastic Moduli ◽  
Damping Ratio ◽  
Lumped Parameter Model ◽  
Model Parameters ◽  
Experimental Measurements ◽  
Body Segments ◽  
Physical Measurements ◽  
Modal Damping

The present study aims to accurately estimate inertial, physical, and dynamic parameters of human body vibratory model consistent with physical structure of the human body that also replicates its dynamic response. A 13 degree-of-freedom (DOF) lumped parameter model for standing person subjected to support excitation is established. Model parameters are determined from anthropometric measurements, uniform mass density, elastic modulus of individual body segments, and modal damping ratios. Elastic moduli of ellipsoidal body segments are initially estimated by comparing stiffness of spring elements, calculated from a detailed scheme, and values available in literature for same. These values are further optimized by minimizing difference between theoretically calculated platform-to-head transmissibility ratio (TR) and experimental measurements. Modal damping ratios are estimated from experimental transmissibility response using two dominant peaks in the frequency range of 0–25 Hz. From comparison between dynamic response determined form modal analysis and experimental results, a set of elastic moduli for different segments of human body and a novel scheme to determine modal damping ratios from TR plots, are established. Acceptable match between transmissibility values calculated from the vibratory model and experimental measurements for 50th percentile U.S. male, except at very low frequencies, establishes the human body model developed. Also, reasonable agreement obtained between theoretical response curve and experimental response envelop for average Indian male, affirms the technique used for constructing vibratory model of a standing person. Present work attempts to develop effective technique for constructing subject specific damped vibratory model based on its physical measurements.

scholarly journals A Fast and Low-Cost Human Body 3D Scanner Using 100 Cameras

2020 ◽  
Vol 6 (4) ◽  
pp. 21
Author(s):  
Mojtaba Zeraatkar ◽  
Khalil Khalili
Keyword(s):  
Human Body ◽  
Low Cost ◽  
Physical Structure ◽  
The Body ◽  
Scanning System ◽  
3D Scanner ◽  
Field Range ◽  
Scanning Time ◽  
Complex Features ◽  
Time Required

The human body is one of the most complicated objects to model because of its complex features, non-rigidity, and the time required to take body measurements. Basic technologies available in this field range from small and low-cost scanners that must be moved around the body to large and high-cost scanners that can capture all sides of the body simultaneously. This paper presents an image-based scanning system which employs the structure-from-motion method. The design and development process of the scanner includes its physical structure, electronic components, and the algorithms used for extracting 3D data. In addition to the accuracy, which is one of the main parameters to consider when choosing a 3D scanner, the time and cost of the system are among the most important parameters for evaluating a scanner system in the field of human scanning. Because of the non-static nature of the human body, the scanning time is particularly important. On the other hand, a high-cost system may lead to limited use of such systems. The design developed in this paper, which utilizes 100 cameras, facilitates the acquisition of geometric data in a fraction of a second (0.001 s) and provides the capabilities of large, freestanding scanners at a price akin to that of smaller, mobile ones.

Mechanical Parameters of Standing Body and Applications in Human–Structure Interaction

2017 ◽  
Vol 09 (02) ◽  
pp. 1750021 ◽  
Author(s):  
Huixuan Han ◽  
Ding Zhou ◽  
Tianjian Ji
Keyword(s):  
Dynamic Characteristics ◽  
Human Body ◽  
Damping Ratio ◽  
Coupled System ◽  
The Body ◽  
Degree Of Freedom ◽  
Least Square ◽  
Mechanical Parameters ◽  
Structure Interaction ◽  
Body Model

In this paper, the dynamic interaction of human body and structure is studied The shaking table experiment with a person standing on a rigid table supported by springs is firstly carried out to determine the dynamic characteristics of the coupled system. It is shown that the body mainly contributes only one degree of freedom to the human-structure coupled system. Then, the two-degree-of-freedom (TDOF) coupled model of the human-structure system is developed through the energy variation by considering the standing human body as an elastic bar of two segments with distributed mass, stiffness and damping. Based on the experiment data, the dynamic parameters of the TDOF coupled system are determined by using the least square method (LSM). The mechanical parameters such as the damping ratio and the distributions of mass and stiffness of the human body model of two segments are identified by adopting the inversing technique Finally, the determined body model is applied to analyze the free vibration of beams and plates occupied by standing persons. The governing differential equations of the human-beam system and the human-plate system are, respectively, derived out. The dynamic characteristics of the human-structure interaction are obtained by the use of the complex mode theory. The results are compared with the experimental ones and those from the finite element simulations. Good agreement is observed for all cases.

Modeling of the Seated Human Body in a Vibrational Medium

2014 ◽  
Vol 658 ◽  
pp. 401-406 ◽  
Author(s):  
Daniela Mariana Barbu
Keyword(s):  
Human Body ◽  
Degrees Of Freedom ◽  
Dynamic Environment ◽  
The Body ◽  
Lumped Parameter Model ◽  
Vibration Effect ◽  
Mechanical Oscillations ◽  
Lumped Parameter ◽  
Irregular Period ◽  
Multi Body

Vibrations are mechanical oscillations produced by regular or irregular period movements of a member or body about its rest position. Vibration can affect visual perception, muscles, concentration, circulation and the respiratory system and at certain levels can even result in physical harm to the body. The effect of vibration on the human body is related to the natural frequency of parts of the human body affected. This paper studies the dynamic characteristics of a seated human body system in a vibration environment. The main result is a multi degrees of freedom lumped parameter model. The model provided an analytical tool for human body dynamics research. It also enabled a primary tool for seat and cushioning design. Combining the geometry and the mechanical characteristics of a structure under large deformation into a lumped parameter model enables successful analysis of the human/seat interface system and provides practical results for body protection in dynamic environment. The relative displacements of human parts are evaluated, which can be a basis for the assessment of vibration risk. It is suggested that the multi-body dynamic model is used to evaluate the vibration effect to the seated subjects.

Anthropometric Assessment of the Mass Distribution Characteristics of the Living Human Body

1976 ◽  
Vol 20 (16) ◽  
pp. 379-383 ◽  
Author(s):  
John T. McConville ◽  
Charles E. Clauser
Keyword(s):  
Mass Distribution ◽  
Human Body ◽  
Accurate Method ◽  
The Body ◽  
Distribution Characteristics ◽  
Body Segments ◽  
Principal Moments Of Inertia ◽  
Distribution Parameters ◽  
First Time ◽  
Anthropometric Assessment

Knowledge of the mass distribution parameters of the human body is essential for the understanding of human kinetics. A significant problem has been the development of a convenient and accurate method for measuring these parameters on the living. This paper reports two studies undertaken (1) to establish, for the first time, the principal moments of inertia of the body and body segments, and (2) to validate a stereometric technique for assessing mass distribution parameters of the living human body.

scholarly journals Segmentation of the human body based on frequency of human electromagnetic radiation

2020 ◽  
Vol 18 (1) ◽  
pp. 268
Author(s):  
Siti Zura A. Jalil ◽  
Siti Armiza Mohd Aris ◽  
Nurul Aini Bani ◽  
Mohd Nabil Muhtazaruddin ◽  
Sahnius Usman
Keyword(s):  
Electromagnetic Radiation ◽  
Human Body ◽  
Roc Analysis ◽  
Operating Characteristic ◽  
Nearest Neighbor ◽  
Human Subjects ◽  
The Body ◽  
K Nearest Neighbor ◽  
Healthy Human ◽  
Body Segments

<p>This paper discusses the body segment recognition based on human electromagnetic radiation frequency. Twenty-three points of human electromagnetic radiation are studied experimentally from thirty-three healthy human subjects. Three human body segments are considered, namely Left, Right and Chakra. For the purpose of recognition, k-Nearest Neighbor (KNN) algorithm is used to classify the segments of the human body. Then, the performances of classification are determined based on the accuracy and Receiving Operating Characteristic (ROC) analysis. It is found that the proposed technique accurately classifies the body segments with 100% accuracy, thus suggest that the proposed technique is significant to classify human body segments.</p>

Correction of Posture Deviations in the Sagittal Plane Using the Pilates Method

2019 ◽  
pp. 3-13
Author(s):  
Alexandru Cîtea ◽  
George-Sebastian Iacob
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Postural Control ◽  
Human Body ◽  
Sagittal Plane ◽  
The Body ◽  
Lower Limbs ◽  
Low Back ◽  
Pilates Method ◽  
The Relationship

Posture is commonly perceived as the relationship between the segments of the human body upright. Certain parts of the body such as the cephalic extremity, neck, torso, upper and lower limbs are involved in the final posture of the body. Musculoskeletal instabilities and reduced postural control lead to the installation of nonstructural posture deviations in all 3 anatomical planes. When we talk about the sagittal plane, it was concluded that there are 4 main types of posture deviation: hyperlordotic posture, kyphotic posture, rectitude and "sway-back" posture.Pilates method has become in the last decade a much more popular formof exercise used in rehabilitation. The Pilates method is frequently prescribed to people with low back pain due to their orientation on the stabilizing muscles of the pelvis. Pilates exercise is thus theorized to help reactivate the muscles and, by doingso, increases lumbar support, reduces pain, and improves body alignment.

Representation of a Human Body: A Comparison Study between Balinese and Javanese Traditional House

Humaniora ◽  
2020 ◽  
Vol 11 (2) ◽  
pp. 83-90
Author(s):  
Anak Agung Ayu Wulandari ◽  
Ade Ariyani Sari Fajarwati
Keyword(s):  
Comparative Study ◽  
Human Body ◽  
Qualitative Method ◽  
Descriptive Analysis ◽  
The Body ◽  
Comparison Study ◽  
Architectural Drawing ◽  
Study Approach ◽  
The Comparative Study ◽  
Head Area

The research would look further at the representation of the human body in both Balinese and Javanese traditional houses and compared the function and meaning of each part. To achieve the research aim, which was to evaluate and compare the representation of the human body in Javanese and Balinese traditional houses, a qualitative method through literature and descriptive analysis study was conducted. A comparative study approach would be used with an in-depth comparative study. It would revealed not only the similarities but also the differences between both subjects. The research shows that both traditional houses represent the human body in their way. From the architectural drawing top to bottom, both houses show the same structure that is identical to the human body; head at the top, followed by the body, and feet at the bottom. However, the comparative study shows that each area represents a different meaning. The circulation of the house is also different, while the Balinese house is started with feet and continued to body and head area. Simultaneously, the Javanese house is started with the head, then continued to body, and feet area.

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