Effect of Assumed Stiffness and Mass Density on the Impact Response of the Human Chest Using a Three-Dimensional FE Model of the Human Body

2006 ◽  
Vol 128 (5) ◽  
pp. 772-776 ◽  
Author(s):  
Hideyuki Kimpara ◽  
Masami Iwamoto ◽  
Isao Watanabe ◽  
Kazuo Miki ◽  
Jong B. Lee ◽  
...  

The mass density, Young’s modulus (E), tangent modulus (Et), and yield stress (σy) of the human ribs, sternum, internal organs, and muscles play important roles when determining impact responses of the chest associated with pendulum impact. A series of parametric studies was conducted using a commercially available three-dimensional finite element (FE) model, Total HUman Model for Safety (THUMS) of the whole human body, to determine the effect of changing these material properties on the predicted impact force, chest deflection, and the number of rib fractures and fractured ribs. Results from this parametric study indicate that the initial chest apparent stiffness was mainly influenced by the stiffness and mass density of the superficial muscles covering the torso. The number of rib fractures and fractured ribs was primarily determined by the stiffness of the ribcage. Similarly, the stiffness of the ribcage and internal organs contributed to the maximum chest deflection in frontal impact, while the maximum chest deflection for lateral impact was mainly affected by the stiffness of the ribcage. Additionally, the total mass of the whole chest had a moderately effect on the number of rib fractures.

Author(s):  
Hideyuki Kimpara ◽  
Masami Iwamoto ◽  
Isao Watanabe ◽  
Kazuo Miki ◽  
Jong B. Lee ◽  
...  

The mass density, Young’s modulus (E), tangent modulus (Et) and yield stress (σy) of the human ribs, sternum, internal organs and muscles play important roles when determining impact responses of the chest associated with pendulum impact. A series of parametric studies was conducted using a commercially available three-dimensional finite element (FE) model, Total HUman Model for Safety (THUMS) of the whole human body, to determine the effect of changing these material properties on the impact force, chest deflection, and the number of rib fractures and fractured ribs. Results from this parametric study indicate that the initial chest stiffness was mainly influenced by the mass density of the muscles covering the torso. The number of rib fractures and fractured ribs were primarily determined by E, Et and σy of the ribcage and sternum. Similarly, the E, Et and σy of the ribcage, which is defined as the bony skeleton of the chest, and sternum and E of the internal organs contributed to the maximum chest deflection in frontal impact, while the maximum chest deflection for lateral impact was mainly affected by the E, Et and σy of the ribcage.


Author(s):  
Kao-Shang Shih ◽  
Thanh An Truong ◽  
Ching-Chi Hsu ◽  
Sheng-Mou Hou

AbstractRib fracture is a common injury and can result in pain during respiration. Conservative treatment of rib fracture is applied via mechanical ventilation. However, ventilator-associated complications frequently occur. Surgical fixation is another approach to treat rib fractures. Unfortunately, this surgical treatment is still not completely defined. Past studies have evaluated the biomechanics of the rib cage during respiration using a finite element method, but only intact conditions were modelled. Thus, the purpose of this study was to develop a realistic numerical model of the human rib cage and to analyse the biomechanical performance of intact, injured and treated rib cages. Three-dimensional finite element models of the human rib cage were developed. Respiratory movement of the human rib cage was simulated to evaluate the strengths and limitations of different scenarios. The results show that a realistic human respiratory movement can be simulated and the predicted results were closely related to previous study (correlation coefficient>0.92). Fixation of two fractured ribs significantly decreased the fixation index (191%) compared to the injured model. This fixation may provide adequate fixation stability as well as reveal lower bone stress and implant stress compared with the fixation of three or more fractured ribs.


Author(s):  
Raed E. El-Jawahri ◽  
Jesse S. Ruan ◽  
Stephen W. Rouhana ◽  
Saeed D. Barbat ◽  
Priya Prasad

Ford Motor Company human body FE model was validated against 3-point & 4-point belted PMHS tests in frontal impact and PMHS knee impact. The chest deflection, chest acceleration, and belt force in frontal impact simulations were compared with the PMHS test data, while the impact force, femur acceleration, pelvis acceleration, and sacrum acceleration of the knee impact simulations were compared with the respective corridors from PMHS tests. The model used represents a 50th percentile adult male. It was used to study the effects of shoulder belt force limit on 3-point and 4-point restrained occupants in frontal impacts without airbags. A 25 g pulse and a shoulder belt load limit of 1, 2, 3, 4, 6, and 8 kN were used for the 3-point and 4-point restraint systems with a rigid steering wheel, front header, and windshield of a stiffer larger vehicle structure. The results showed that the head acceleration and the chest deflection of the 4-point belt system are less than the respective cases of the 3-point system while the chest acceleration levels were about the same in 3-point and 4-point belt. The mid-shaft femur forces were always higher in the 4-point belt than those of the 3-point belt.


2019 ◽  
Vol 14 ◽  
pp. 155892501882531 ◽  
Author(s):  
Li Duan ◽  
Zhong Yueqi ◽  
Wu Ge ◽  
Hu Pengpeng

In this article, we presented a new automatic three-dimensional-scanned garment fitting method for A-Pose-scanned human models. Both the garment and the human body were decomposed based on feature lines defined by various landmarks. The patches of the three-dimensional garment were automatically positioned around the human model by setting up the correspondence via feature matching. Virtual sewing was engaged to obtain the final results of virtual dressing. The penetration between cloth model and human model was solved by a geometrical method constrained by Laplacian-based deformation. The experimental results indicated that the proposed method was an efficient way for redressing various garments onto various human models while maintaining the original geometrical features of garments.


2015 ◽  
Vol 138 (1) ◽  
Author(s):  
Folly Abevi ◽  
Alain Daidie ◽  
Michel Chaussumier ◽  
Marc Sartor

In this paper, an original approach is proposed to calculate the static load distribution and the axial stiffness of a planetary roller screw (PRS) mechanism. Assuming that the external loading is shared equally over an arbitrary number of rollers, only a sector of the system is represented to save on computing time. The approach consists in using a structure of bars, beams, and nonlinear springs to model the different components of the mechanism and their interactions. This nonlinear model describes the details of the mechanism and captures the shape of the nut as well as the bending deformation of the roller. All materials are assumed to operate in the elastic range. The load distribution and the axial stiffness are determined in three specific configurations of the system for both compressive and tensile loads. Further, the influence of the shape of the nut is studied in the case of the inverted PRS. The results obtained from this approach are also compared to those computed with a three-dimensional finite-element (3D FE) model. Finally, since the calculations appear to be very accurate, a parametric study is conducted to show the impact of the bending of the roller on the load distribution.


CARALL hybrid material has been extensively used in the aircraft structure due to their competitive impact strength. Low velocity impact test is utilized to evaluate the impact and damage properties for such material. It is also employed to observe complex damage mechanisms. A numerical modelling is an alternative way for impact assessment. This paper investigates the impact and damage properties under low velocity impact using numerical modeling and experimental work. A three-dimensional (3D) finite element (FE) model was devolved and validated with two studies from the literature. This model was meshed with solid elements. It was subjected to 2.4 m/s impact velocity and to 10 J impact energy. Absorbed energy, penetration, impact load and damage morphology were obtained. The impact energy was efficiently absorbed by the material. Both aluminum alloy layers underwent plastic deformation whereas the fiber layer failed. A macroscopic cross-sectional morphology was presented using the FE model. An agreement between the numerical and the experiment results were achieved and discussed.


2019 ◽  
Vol 2 (1) ◽  
pp. 138-160 ◽  
Author(s):  
Scott Zimmerman ◽  
Russel.J. Reiter

Melatonin is fundamental to the lighting, display, and architectural industries as the primary biomarker used in circadian theory. Billions of dollars are being spent on research, product development, and marketing based on the impact of visible light on melatonin produced by the pineal gland. It has now been shown that the mitochondria produce melatonin in many cells in quantities which are orders of magnitude higher than that produced in the pineal gland. This subcellular melatonin does not necessarily fluctuate with our circadian clock or release into the circulation system, but instead has been proposed to be consumed locally in response to the free radical density within each cell, in particular in response to Near Infrared (NIR) exposure. The main point of this review hypothesizes that the subcellular melatonin is being produced in response to the NIR photons which make up the majority of natural sunlight. Given the number of cells and quantity of subcellular melatonin identified to date, it is reasonable to propose that the body produces and maintains a melatonin reservoir that is separate and apart from the circulatory melatonin generated by the pineal gland. To understand how sunlight may support or stimulate this antioxidant reservoir, it becomes necessary to quantify the free radical density in various parts of the human body. To do this, it is necessary to move away from two-dimensional empirical approaches and develop three-dimensional bio-optical models based on the underlying biological processes at play. Three-dimensional Mechanistic Bio-optical Models (MBM) of the skin, eye, and brain based on non-sequential optical ray tracing and Electron Spin Resonance (ESR) data clearly indicate that the NIR portion of natural sunlight provides the primary stimulus during the day to the majority of the cells in the human body, impacting over 60% of the cells in an adult body and 100% of the cells in the fetus and young children. It is also shown that optically, the human body, under the assumption of natural sunlight, has developed optical mechanisms to gather and localize NIR photons in the most sensitive areas of the human body: blood vessels, retina, brain, skin, and even the fetus.  That assumption is no longer valid in modern societies where the majority of our time is spent exposed to visible only lighting and displays, which emit zero NIR photons. Based on an optical and biological review of the literature and the MBM results, it is proposed that the NIR portion of natural sunlight stimulates an excess of antioxidants in each of our healthy cells and that the cumulative effect of this antioxidant reservoir is to enhance the body’s ability to rapidly and locally deal with changing conditions throughout the day. In this approach the role of circulatory melatonin produced by the pineal gland is to provide an efficient method of delivering supplemental melatonin during periods of low cellular activity and solar stimulus to damaged or aging cells in both diurnal and nocturnal animals. While circulatory melatonin may be the “Hormone of Darkness”, subcellular melatonin may be the “Hormone of Daylight”. 


2013 ◽  
Vol 658 ◽  
pp. 464-470
Author(s):  
Supakit Rooppakhun ◽  
Sarawut Bua-Ngam

In Thailand, according to the bus accident statistics referred to Department of Land Transport (DLT), the highest risk represents the frontal crash accidents. In case of frontal crashworthiness, the high- decker bus safety was referred to the regulation no.29 of United Nations Economic Commission for Europe (ECE-R29). In this study, the frontal impact analysis of the high-decker passenger bus structure based on ECE-R29 using Finite Element (FE) analysis was focused on. The energy absorption including to the total deformation of the frontal cabin were evaluated. Three-dimensional FE model of frontal bus structure with- and without- simple impact attenuator were created and analyzed using ANSYS/Explicit software. In accordance with the results, the average magnitude of kinetic energy in case of impact attenuator revealed the value lower than those without impact attenuator owing to absorb energy in the impact attenuator. In addition, the total deformation regarding to the safe zone of the frontal cabin in the case of with impact attenuator were lower than without impact attenuator as 75.8%. Therefore, the frontal impact attenuator should be recommended to a high-decker bus for the driver protection in the event of crash accident.


Author(s):  
Н. M. Mustafina ◽  
I. I. Starchenko ◽  
V. М. Koka ◽  
Ye. I. Lukachina ◽  
V. V. Chernyak

This article highlights the analysis of available data about the impact of food additives on a human body. We specified the meaning of the term "food additives", paid attention to the history of discovering and applying food additives, described the differences between natural and synthetic food additives. According to the literature, most food additives used in modern food industry can be considered quite safe. The safety of food additives is determined on the basis of extensive comparative studies, and the use of food additives is prohibited unless they have been tested and approved by the relevant authorities. But, with the development of analytical methods, the emergence of new experimental data, the question of the possible negative impacts of one or another additive on individual organs and systems of the human body can be reconsidered. In particular, certain food additives that were previously considered harmless, for example E 240, E 121, are now recognized as very dangerous and prohibited for use. It has been proven that food supplements that are harmless to one person can have a negative effect on another. Therefore, it is recommended to limit the use of food additives for children, the elderly and people prone to allergic reactions. The article describes in detail the results of experimental studies about the negative impact of specific additives, in particular ponceau 4R, sodium nitrite and monosodium glutamate on individual internal organs. Attention is focused on the group of food additives such as nitrogen compounds, which due to the biotransformation can result in the nitrite formation. An excess of the latter, in turn, according to some researchers, can provoke the development of malignant tumours in various organs, primarily in the terminal parts of the colon. Thus, the impact of various combinations of food additives on the morpho-functional state of the internal organs requires further detailed research.


2020 ◽  
Vol 27 (5) ◽  
pp. 533-553 ◽  
Author(s):  
Haibao Liu ◽  
Jun Liu ◽  
Yuzhe Ding ◽  
Jin Zhou ◽  
Xiangshao Kong ◽  
...  

Abstract Carbon-fibre/epoxy-matrix composites used in aerospace and vehicle applications are often susceptible to critical loading conditions and one example is impact loading. The present paper describes a detailed experimental and numerical investigation on the relatively low-velocity (i.e. <10 m/s) impact behaviour of such composite laminates. In particular, the effects of the geometry of the impactor have been studied and two types of impactor were investigated: (a) a steel impactor with a hemispherical head and (b) a flat-ended steel impactor. They were employed to strike the composite specimens with an impact energy level of 15 J. After the impact experiments, all the composite laminates were inspected using ultrasonic C-scan tests to assess the damage that was induced by the two different types of impactor. A three-dimensional finite-element (FE) model, incorporating a newly developed elastic-plastic damage model which was implemented as a VUMAT subroutine, was employed to simulate the impact event and to investigate the effects of the geometry of the impactor. The numerical predictions, including those for the loading response and the damage maps, gave good agreement with the experimental results.


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