Multibody Dynamics Approaches for Study on Good and Bad Whole-Body Vibrations

2018 ◽  
Author(s):  
Shanzhong (Shawn) Duan
Keyword(s):  
Multibody Dynamics ◽  
Human Body ◽  
Occupational Diseases ◽  
Equations Of Motion ◽  
Stable Condition ◽  
Rigid Bodies ◽  
Whole Body ◽  
Boundary Line ◽  
Dynamics Models ◽  
Whole Body Vibrations

Whole-body vibrations (WBV) have been used for enhancing muscle strength and bone density of human bodies, training athletes and dancers, and helping people with disabling conditions and rehabilitations. On the other hand, WBV-induced occupational diseases have been reported. Researchers in automotive, farm equipment, and heavy machinery have put forward a few models for studying harmful vibrations on human bodies. This paper will review the effects of frequencies and magnitudes of WBV on a human body. Discussion of effects of frequencies and magnitudes on a human body will provide a preliminary boundary line between good and bad whole-body vibrations. Two multibody dynamics models and associated application cases will be proposed to show how the models may be used to represent whole-body vibrations under both good and bad vibrations. Three basic vibration elements associated with whole-body vibrations of the human body are handled as follows: (1) ligaments are modeled as spring elements; (2) muscles and tendons are modeled as damping elements; (3) bones are modeled as rigid bodies with masses/inertias and connected by idealized massless joints. In such a biomechanical vibration system, the spring elements (ligaments) help hold the human body skeleton structure in a stable condition, pass spring forces and potential energy to rigid bodies (bones) for bone vibrational motions. The damping elements (muscles and tendons) play roles of a damper and absorb energy input from the whole-body vibration resource. Based on the proposed multibody dynamics models, Kane’s method is then used to develop equations of motion. The equations will be further used for development of simulation algorithms to understand frequencies and magnitudes of both good and bad whole-body vibrations. The models may be utilized to understand why frequencies and magnitudes of whole-body vibrations will provide benefits to human health under one situation but cause occupational diseases under another scenario.

scholarly journals Applying Kane’s Method to Model the Response of the Human Body to Whole-Body Vibration

2014 ◽  
Author(s):  
Emma Gantzer ◽  
Shanzhong (Shawn) Duan ◽  
Teresa Binkley
Keyword(s):  
Human Body ◽  
Equations Of Motion ◽  
Whole Body Vibration ◽  
Rigid Bodies ◽  
Skeletal Structure ◽  
Whole Body ◽  
Mineral Density ◽  
Body Vibration ◽  
Kane’S Method ◽  
Kane's Method

Low magnitude, high frequency whole-body vibration (WBV) has been found to increase bone mineral density in both animal and clinical studies [1,2,3]. The mechanism behind this phenomenon is unknown and a model would be beneficial to assist in analyzing the effects of WBV on the human skeleton. In this paper, Kane’s method is used to find the equations of motion for a multi-body model of the human body standing on a vibration platform [4]. The model consists of nine rigid bodies connected by ideal joints that simulate the skeletal structure of the human body. Spring and damper elements represent the ligaments and tendons connecting the rigid bodies; a sinusoidal force function denotes the vibration input of the platform. This model is lumped, assuming no relative motion between the feet and the vibration platform. The equations of motion generated by Kane’s method are solved in MATLAB using fourth-order Runge-Kutta. The results from the simulation were compared to experimental data in order to validate the model.

Modeling of Human Reactions to Whole-Body Vibration

1987 ◽  
Vol 109 (3) ◽  
pp. 210-217 ◽  
Author(s):  
Farid M. L. Amirouche
Keyword(s):  
Human Body ◽  
Equations Of Motion ◽  
Vertical Direction ◽  
The Body ◽  
Whole Body ◽  
Connective Tissues ◽  
Finite Segment ◽  
Body Vibration ◽  
Forcing Function ◽  
Impulse Function

A computer-automated approach for studying the human body vibration is presented. This includes vertical, horizontal, and torsional vibration. The procedure used is based on Finite Segment Modeling (FSM) of the human body, thus treating it as a mechanical structure. Kane’s equations as developed by Huston et al. are used to formulate the governing equations of motion. The connective tissues are modeled by springs and dampers. In addition, the paper presents the transient response of different parts of the body due to a sinusoidal forcing function as well as an impulse function applied to the lower torso in the vertical direction.

High-Fidelity Modeling of a Backhoe Digging Operation Using an Explicit Multibody Dynamics Code With Integrated Discrete Particle Modeling Capability

2013 ◽  
Author(s):  
Shahriar G. Ahmadi ◽  
Tamer M. Wasfy ◽  
Hatem M. Wasfy ◽  
Jeanne M. Peters
Keyword(s):  
Multibody Dynamics ◽  
Search Algorithm ◽  
Equations Of Motion ◽  
Friction Model ◽  
Rigid Bodies ◽  
Contact Friction ◽  
Contact Detection ◽  
High Fidelity ◽  
Normal Contact ◽  
Contact Search

A high-fidelity multibody dynamics model for simulating a backhoe digging operation is presented. The backhoe components including: frame, manipulator, track, wheels and sprockets are modeled as rigid bodies. The soil is modeled using cubic shaped particles for simulating sand with appropriate inter-particle normal and frictional forces. A penalty technique is used to impose both joint and normal contact constraints (including track-wheels, track-terrain, bucket-particles and particles-particles contact). An asperity-based friction model is used to model joint and contact friction. A Cartesian Eulerian grid contact search algorithm is used to allow fast contact detection between particles. A recursive bounding box contact search algorithm is used to allow fast contact detection between polygonal contact surfaces. The governing equations of motion are solved along with joint/constraint equations using a time-accurate explicit solution procedure. The model can help improve the performance of construction equipment by predicting the actuator and joint forces and the vehicle stability during digging for various vehicle design alternatives.

scholarly journals Spine injury assessment under spaceflight landing conditions using multibody model

2018 ◽  
Vol 232 (4) ◽  
pp. 555-567
Author(s):  
AA Pasha Zanoosi ◽  
R Kalantarinejad ◽  
M Haghpanahi
Keyword(s):  
Finite Element ◽  
Human Body ◽  
Sagittal Plane ◽  
Rigid Bodies ◽  
Whole Body ◽  
Spine Injury ◽  
Human Body Model ◽  
Multibody Modeling ◽  
Multibody Model ◽  
Injury Assessment

The novelty of the study relies on the fact that current simulations of human body to assess spine injury are based on finite element method. Spine injury assessment is an important point in designing spacecraft seat especially during landing. The finite element-based human body simulations are very time-consuming and computationally expensive. These problems make it difficult to perform high computational simulations such as optimization, sensitivity analysis, and so forth. Hence, in this study, it is tried to resolve these problems by developing a multibody model of human body in landing phase of spacecraft. This model makes designers able to perform corresponding simulations faster with acceptable accuracy. This study presents a dynamic multibody model of spacecraft seat-occupant system for spine injury assessment under landing conditions. The landing situation of spacecraft exposes shock loads to the spacecraft and astronaut. Hence, spine injury assessment under landing conditions enables optimal injury design of seat-occupant system. The modeling method is based on using the multibody modeling to achieve a detailed description containing the nonlinear properties and the accuracy of a multibody dynamic model considering whole body comprising stretching of vertebrae. The human body model comprises head, spine, femur, and shank lying on a flexible polyurethane foam as seat cushion. To model the spine, viscera, and pelvis in the sagittal plane, the spine column considered to be rigid bodies accompanied by spring-damper elements. To validate the developed model, the modal analysis and seat-to-head transmissibility of the spine has been validated by comparing with previously published models. Finally, as an application, the developed model has been exposed to a landing shock load for spine injury assessment.

A Literature Survey of Biodynamic Models for Whole Body Vibration and Vehicle Ride Comfort

2012 ◽  
Author(s):  
Prasad Bhagwan Kumbhar ◽  
Peijun Xu ◽  
Jingzhou (James) Yang
Keyword(s):  
Human Body ◽  
Ride Comfort ◽  
Whole Body Vibration ◽  
Element Model ◽  
Rigid Bodies ◽  
Literature Survey ◽  
Whole Body ◽  
Fourth Power ◽  
Fe Model ◽  
Body Vibration

Vehicle ride comfort plays an important role in the vehicle design. Human body is very sensitive to whole body vibration. Vehicle ride comfort has brought lots of concerns in recent years due to requirement of better ride comfort performance for newly developed vehicles. Vehicle ride comfort has a direct effect on driver’s performance and will result in overall customer satisfaction. Various papers have reported vehicle ride comfort and various biodynamic models have been built in the literature. However, there is a lack of a comprehensive literature survey to summarize all biodynamic models for whole body vibration and vehicle ride comfort. The purpose of this paper is to have a literature review of biodynamic models. So this paper initially focuses on various health issues due to whole body vibrations. Whole body vibration transfers environmental vibration to human body through a large contact area. Vibration evaluation methods such as weighted root mean square (r.m.s.) acceleration method, fourth power VDV method are discussed. Along with that the paper will focus on various biodynamic response functions. Human models in the literature are divided into three main groups: lumped parameter (LP), finite element model (FE), and multibody model (MB). In the LP model, human body is represented by several concentrated masses which are connected by springs and dampers. The FE model considers that human body consists of numerous finite elements. And in MB model, human body is made of several rigid bodies connected by bushing element for both translational and rotational motion. So this paper thoroughly summarizes various models developed to reduce human body vibration. At the end, four different approaches of assessing ride comfort are summarized. These four approaches are ride measurement in vehicles, ride simulator test, shaker table test and subjective ride measurement.

Whole Body Vibrations Exposure to Malaysian Driver Using Novel IKaz Method

2012 ◽  
Vol 165 ◽  
pp. 21-25 ◽  
Author(s):  
Ahmad Rasdan Ismail ◽  
Mohd Zaki Nuawi ◽  
Nur Farhana Kamaruddin ◽  
Mohd Nizam Ab Rahman
Keyword(s):  
Human Body ◽  
Motor Vehicle ◽  
Whole Body ◽  
Low Back ◽  
Analysis Method ◽  
Accelerometer Sensor ◽  
Daily Exposure ◽  
High Magnitude ◽  
Statistical Analysis Method ◽  
Whole Body Vibrations

A car is a wheeled motor vehicle used for driving and transporting passengers. Therefore, cars are one of the most important forms of transportation worldwide. However, high magnitude of whole-body vibration (WBV) that can be associated with the car may lead to various diseases and health problems, such as low back pain, in humans. This study intended to present the value of Daily Exposure to Vibration A(8) and Vibration Dose Value (VDV) experienced by the car driver, with care taken to elucidate the effects of WBV on the human body. In addition, this study is done to implements a newly developed statistical analysis method called I-kaz 3D to determine the vibration level accordingly. The high value of I-kaz 3D coefficient corresponds to the high VDV value and otherwise. This study was conducted on a national car. The WBV exposure was measured for 10 min. Data was collected using an IEPE(ICPTM) accelerometer sensor connected to a DT9837 device, capable of effectively measuring and analyzing the vibration. The vibration results were displayed on a personal computer using a custom graphical user interface (GUI). From the results gathered, it is confirm that WBV absorbed by the human body increases with an increase in the duration and magnitude of vibration exposure by the driver, illustrated by the increase in the value of daily exposure to vibration A(8) and the calculated vibration dose value (VDV).

Modeling and Simulation of Shoulder-Humerus Complex via Multibody Dynamics for a Walking Elder Using a Cane

2016 ◽  
Author(s):  
Shanzhong (Shawn) Duan
Keyword(s):  
Multibody Dynamics ◽  
Sports Medicine ◽  
Soft Tissues ◽  
Equations Of Motion ◽  
Computer Software ◽  
Rigid Bodies ◽  
Upper Body ◽  
Upper Arm ◽  
Shoulder Blade ◽  
Multibody Dynamics Model

The shoulder is a very mobile joint. Because of the mobility, the shoulder is considered to have an inherent weakness. The joint consists of three major bones, the clavicle, scapula and humerus. These bones are more commonly called the collarbone, shoulder blade, and upper arm bone, respectively. Collectively, the shoulder is referred to as the scapula-humeral-clavicle complex. The joint between the humerus and scapula is a ball-socket joint. The joint between the scapula and acromial process allows for some movement but is primarily fixed. The ligaments, tendons, and muscles surround the shoulder to provide stability, movement, and limit the amount of rotation. In this paper, a multibody dynamics model of the shoulder-upper arm complex is presented. Three major bones clavicle, scapula, and Humerus in the shoulder-upper arm complex are represented by rigid bodies. The soft tissues such as tendons, ligaments, and muscles are modeled as springs and actuators respectively attached to the rigid bodies. The joints between the bones are expressed as ideal kinematic joints. Kane’s equations are then used to derive equations of motion of this multibody system. Based on the model, an elder who uses a cane with his or her shoulder-upper arm complex force to support his or her upper body weight during walking is analyzed. Commercial computer software is used to create the multibody shoulder-upper arm complex computational model and then carry out simulation. The model may be utilized in motion analysis of elderly people and sports medicine to study fatigue mechanism and prevent injuries of the shoulder-upper arm complex.

scholarly journals Development of a Five-Degree-of-Freedom Seated Human Model and Parametric Studies for Its Vibrational Characteristics

2018 ◽  
Vol 2018 ◽  
pp. 1-15 ◽  
Author(s):  
Jong-Jin Bae ◽  
Namcheol Kang
Keyword(s):  
Equations Of Motion ◽  
Degree Of Freedom ◽  
Human Model ◽  
Whole Body ◽  
Mode Shapes ◽  
Vibrational Characteristics ◽  
Parametric Studies ◽  
Linearized Model ◽  
Nonlinear Equations Of Motion ◽  
Whole Body Vibrations

This study focuses on the biodynamic responses of a seated human model to whole-body vibrations in a vehicle. Five-degree-of-freedom nonlinear equations of motion for a human model were derived, and human parameters such as spring constants and damping coefficients were extracted using a three-step optimization processes that applied the experimental data to the mathematical human model. The natural frequencies and mode shapes of the linearized model were also calculated. In order to examine the effects of the human parameters, parametric studies involving initial segment angles and stiffness values were performed. Interestingly, mode veering was observed between the fourth and fifth human modes when combining two different spring stiffness values. Finally, through the frequency responses of the human model, nonlinear characteristics such as frequency shift and jump phenomena were clearly observed.

scholarly journals Experimental identification of the subjective reception of external stimuli during wheelchair driving

2021 ◽  
Vol 11 (1) ◽  
pp. 1141-1149
Author(s):  
Gabriela Chwalik-Pilszyk ◽  
Zygmunt Dziechciowski ◽  
Magdalena Kromka-Szydek ◽  
Marek S. Kozień
Keyword(s):  
Human Body ◽  
The Body ◽  
Whole Body ◽  
Body Parts ◽  
Vibration Signals ◽  
Experimental Identification ◽  
External Stimuli ◽  
The Impact ◽  
Whole Body Vibrations

Abstract The aim of this article is identification of the subjective reception of external stimuli during wheelchair driving by analyses of vibration signals obtained from measurements. The identification concerns the impact of vibrations generated during crossing various types of pavements on the discomfort feelings of the selected human body parts (mainly the spine). The identification used the measurements of the whole body vibrations received by the user of the wheelchair. The research focuses mainly on the analysis in the frequency ranges corresponding to the vibration resonance of the spine. It is because respondents of the conducted surveys selected the spine as one of the most sensitive parts of the body.

Simulation of Forces Acting in the Spine under Continuous and Transient Whole-Body Vibrations by Means of a Biomechanical Model

1997 ◽  
Vol 16 (4) ◽  
pp. 229-243
Author(s):  
Martin Fritz
Keyword(s):  
Lumbar Spine ◽  
Health Risk ◽  
Compressive Force ◽  
Biomechanical Model ◽  
Rigid Bodies ◽  
Whole Body ◽  
Age And Gender ◽  
And Gender ◽  
As Stress ◽  
Whole Body Vibrations

Investigations reveal that exposure to whole-body vibrations can induce degenerative changes in the lumbar spine. The purpose of this study was to assess the health risk on the basis of predicted forces transmitted in the spine. The forces were simulated by means of a biomechanical model, where ten rigid bodies represent the trunk (5), the neck (4), and the head (1) and one additional body imitates the vibrating seat. As stress examples, the model movements were simulated under sinusoidal and shock containing vibrations in the x- and z-direction. In the lumbar spine the resulting shear force was lower than the compressive force. The peak values of the compressive force were −834 N under the sinusoidal and −1188 N under the shock containing vibration. Assessing the health risk, the predicted spine forces have to be compared with the strength of the spine regarding the age and gender of the worker and the dependence on the number of load cycles.

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