A Numerical Side Impact Model to Investigate Thoracic Injury in Lateral Impact Scenarios PDF Download

Author: Campbell. Brett M.
Publisher:
ISBN: 9780494547519
Category :
Languages : en
Pages : 205

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Book Description
Although there have been tremendous improvements in crash safety there has been an increasing trend in side impact fatalities, rising from 30% to 37% of total fatalities from 1975 to 2004 (NHTSA, 2004). Between 1979 and 2004, 63% of AIS[greq]4 injuries in side impact resulted from thoracic trauma (NHTSA, 2004). Lateral impact fatalities, although decreasing in absolute numbers, now comprise a larger percentage of total fatalities. Safety features are typically more effective in frontal collisions compared to side impact due to the reduced distance between the occupant and intruding vehicle in side impact collisions. Therefore, an increased understanding of the mechanisms governing side impact injury is necessary in order to improve occupant safety in side impact auto crash. This study builds on an advanced numerical human body model with focus on a detailed thoracic model, which has been validated using available post mortem human subject (PMHS) test data for pendulum and side sled impact tests (Forbes, 2005).

Author: Brett M. Campbell
Publisher:
ISBN:
Category :
Languages : en
Pages : 205

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Book Description
Although there have been tremendous improvements in crash safety there has been an increasing trend in side impact fatalities, rising from 30% to 37% of total fatalities from 1975 to 2004 (NHTSA, 2004). Between 1979 and 2004, 63% of AIS[greq]4 injuries in side impact resulted from thoracic trauma (NHTSA, 2004). Lateral impact fatalities, although decreasing in absolute numbers, now comprise a larger percentage of total fatalities. Safety features are typically more effective in frontal collisions compared to side impact due to the reduced distance between the occupant and intruding vehicle in side impact collisions. Therefore, an increased understanding of the mechanisms governing side impact injury is necessary in order to improve occupant safety in side impact auto crash. This study builds on an advanced numerical human body model with focus on a detailed thoracic model, which has been validated using available post mortem human subject (PMHS) test data for pendulum and side sled impact tests (Forbes, 2005).

Author: Kin F. Yuen
Publisher:
ISBN:
Category :
Languages : en
Pages : 232

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Book Description
Thoracic injury is the most dominant segment of automotive side impact traumas. A numerical model that can predict such injuries in crash simulation is essential to the process of designing a safer motor vehicle. The focus of this study was to develop a numerical model to predict lung response and injury in side impact car crash scenarios. A biofidelic human body model was further developed. The geometry, material properties and boundary condition of the organs and soft tissues within the thorax were improved with the intent to ensure stress transmission continuity and model accuracy. The thoracic region of the human body model was revalidated against three pendulum and two sled impact scenarios at different velocities. Other body regions such as the shoulder, abdomen, and pelvis were revalidated. The latest model demonstrated improvements in every response category relative to the previous version of the human body model. The development of the lung model involved advancements in the material properties, and boundary conditions. An analytical approach was presented to correct the lung properties to the in-situ condition. Several injury metric predictor candidates of pulmonary contusion were investigated and compared based on the validated pendulum and sled impact scenarios. The results of this study confirmed the importance of stress wave focusing, reflection, and concentration within the lungs. The bulk modulus of the lung had considerable influence on injury metric outcomes. Despite the viscous criterion yielded similar response for different loading conditions, this study demonstrated that the level of contusion volume varied with the size of the impact surface area. In conclusion, the human body model could be used for the analysis of thoracic response in automotive impact scenarios. The overall model is capable of predicting thoracic response and lung contusion. Future development on the heart and aorta can expand the model capacity to investigate all vital organ injury mechanisms.

Author: Donata Gierczycka
Publisher:
ISBN:
Category : Accidents
Languages : en
Pages : 152

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Book Description
Car accidents are amongst the most common causes of fatalities for a younger population in developed countries and world-wide. While research using Anthropometric Test Devices (ATDs) has led to improvements in frontal impact occupant protection, epidemiological data on the effectiveness of devices for side impact protection remains inconclusive. Current regulatory physical side impact tests are limited to standardized full-vehicle Moving Deformable Barrier and rigid pole impacts, only one seating position of the occupant, and a unidirectional occupant surrogate (side impact ATD). To address some limitations of the existing research methods, and expand the understanding of the occupant response and potential for injury, numerical Human Body Models (HBMs) have been developed as repeatable, biofidelic, omni-directional, and frangible occupant surrogates. The overall goal of this study was to improve the understanding of the underlying sources of conflicting epidemiological and physical test data on thoracic response in side impacts. This study applied two highly detailed HBMs in parametric investigations with simple to complex impact scenarios ranging from a pendulum, rigid-wall side sled, to a full-vehicle lateral impact and an accident reconstruction. Subsequently, a thoracic side airbag and three-point seatbelt models were developed and integrated with the vehicle model to study the effect of occupant pre-crash position on the potential for injury. Occupant response assessment included global criteria (chest deflection and viscous criterion), local measurements at different thorax levels, spine kinematics, and prediction of rib fracture locations and lung response. This research identified limitations in current analysis methods, demonstrating effects on occupant response of pre-crash arm position, which is known to vary widely among occupants. The magnitude of the arm effect was dependent on the lateral impact scenario, where the occupant response demonstrated the highest sensitivity to arm orientation in the full vehicle impact. The arm position effect was more significant than changes in response to four restraint combinations, where the assessment of the restraint performance was also dependent on the thoracic response measurement locations and method. A parametric study using detailed HBM, vehicle and restraint models provided new understanding of occupant response in side impact crash scenarios.

Author: Patrick A. Forbes
Publisher: University of Waterloo
ISBN:
Category : Chest
Languages : en
Pages : 206

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Book Description
Occupant thoracic injury incurred during side impact automotive crashes constitutes a significant portion of all fatal and non-fatal automotive injuries. The limited space between the impacting vehicle and occupant can result in significant loads and corresponding injury prior to deceleration of the impacting vehicle. Within the struck vehicle, impact occurs between the occupant and various interior components. Injury is sustained to human structural components such as the thoracic cage or shoulder, and to the internal visceral components such as the heart, lungs, or aorta. Understanding the mechanism behind these injuries is an important step in improving the side impact crash safety of vehicles. This study is focused on the development of a human body numerical model for the purpose of predicting thoracic response and trauma in side impact automotive crash. The human body model has been created using a previously developed thoracic numerical model, originally used for predicting thoracic trauma under simple impact conditions. The original version of the thorax model incorporated three-dimensional finite element representations of the spine, ribs, heart, lungs, major blood vessels, rib cage surface muscles and upper limbs. The present study began with improvements to the original thorax model and furthered with the development of remaining body components such that the model could be assessed in side impact conditions. The improvements to the thoracic model included improved geometry and constitutive response of the surface muscles, shoulder and costal cartilage. This detailed thoracic model was complimented with a pelvis, lower limbs, an abdomen and a head to produce the full body model. These components were implemented in a simplified fashion to provide representative response without significant computational costs. The model was developed and evaluated in a stepwise fashion using experimental data from the literature including side abdominal and pelvic pendulum impact tests. The accuracy of the model response was investigated using experimental testing performed on post mortem human subjects (PMHS) during side and front thoracic pendulum impacts. The model produced good agreement for the side thoracic and side shoulder pendulum impact tests and reasonable correlation during the frontal thoracic pendulum impact test. Complex loading via side sled impact tests was then investigated where the body was loaded unbelted in a NHTSA-type and WSU-type side sled test system. The thorax response was excellent when considering force, compression and injury (viscous criterion) versus time. Compression in the thorax was influenced by the arm position, which when aligned with the coronal plane produced the most aggressive form of compressive loading possible. The simplified components provided good response, falling slightly outside experimental response corridors defined as one standard deviation from the average of the experimental PMHS data. Overall, the predicted model response showed reasonable agreement with the experimental data, while at the same time highlighting areas for future developments. The results from this study suggested that the numerical finite element model developed herein could be used as a powerful tool for improving side impact automotive safety.

Author: Mohamed Taher Zaki Hassan
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
The increasing number of fatalities and injuries in motor vehicle accidents highlights the importance of studying occupants' response during collisions; specifically, the head and neck due to their vulnerability. In this research program, we study the occupant kinematic response and kinetic behavior during frontal, rear and lateral motor vehicle collisions. In view of its severity and commonality, rear-end collisions leading to whiplash, have been given additional attention. The work, which is conducted analytically, numerically and experimentally, is divided into four integrated sections. First, an analytical multibody dynamics model (MBD) of the head and the neck was developed to determine the head response during simulated frontal, lateral and rear impacts. Second, extensive nonlinear dynamic finite element (FE) simulations were carried out to study the occupant response in the aforementioned impact scenarios using detailed vehicle and occupant numerical models. Third, a novel head-neck prototype was developed to experimentally validate the newly developed MBD and FE models. Fourth, a novel shock absorber was developed using foam-filled frusta. The FE simulations were extended to examine a number of safety strategies, involving seat belt, head restraint, airbag and shock absorber on the occupant response during rear-end collisions. The outcomes of this work provide greater understanding of occupants' neck injury mechanism in vehicle collisions. Our results further reveal that in frontal impacts, the capsular ligament (CL) and the interspinous ligament (ISL) are vulnerable to injury, while in lateral collisions, the highest ligament elongation was reported for the CL, exceeding a stipulated injury threshold. In rear-end collisions, the anterior longitudinal ligament was at risk of injury, as well as the ISL and the CL during neck flexion. Our work reveals that the frontal airbag plays an important role in preventing excessive neck flexion in rear impact, and that the newly proposed shock absorber can lead to improved occupant safety. Additionally, it further shows that the experimentally developed head-neck 3D printed prototype response is in good agreement with the MBD and FE predictions. The prototype can be used as the core for developing head-neck models in future anthropomorphic test dummies.

Author: Chwee Teck Lim
Publisher: Springer Science & Business Media
ISBN: 3642145159
Category : Technology & Engineering
Languages : en
Pages : 1747

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Book Description
Biomechanics covers a wide field such as organ mechanics, tissue mechanics, cell mechanics to molecular mechanics. At the 6th World Congress of Biomechanics WCB 2010 in Singapore, authors presented the largest experimental studies, technologies and equipment. Special emphasis was placed on state-of-the-art technology and medical applications. This volume presents the Proceedings of the 6th WCB 2010 which was hold in conjunction with 14th International Conference on Biomedical Engineering (ICBME) & 5th Asia Pacific Conference on Biomechanics (APBiomech). The peer reviewed scientific papers are arranged in the six themes Organ Mechanics, Tissue Mechanics, Cell Mechanics, Molecular Mechanics, Materials, Tools, Devices & Techniques, Special Topics.

Author: Raymond Franklin Neathery
Publisher:
ISBN:
Category :
Languages : en
Pages : 22

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Author: H. C. Gabler
Publisher:
ISBN:
Category :
Languages : en
Pages : 27

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Book Description

Author: Nitheesh Sasikumar
Publisher:
ISBN:
Category : Electronic dissertations
Languages : en
Pages : 96

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Book Description
Significant advancements in enhancing passenger safety and vehicle structures have been made in the automotive industry to protect the occupants and to minimize the injuries during crash events. Variety of crash tests, based on federal regulatory standards, have been performed with an end goal to examine the occupant kinematics and potential injury responses. Among different automotive crash scenarios, the frontal impact is the most common type of accident, which has been considered in this study. In recent years, computer-aided engineering tools have been extensively utilized in modeling, analysis and design of vehicle structures and occupant safety systems. The primary reason for the development and use of simulation models is to reduce the number of full-scale sled tests performed, which require vast flow time and are associated with significant cost. This thesis entirely focuses on the comparison of dynamic responses of human body models versus the crash dummy models in various vehicle frontal federal regulatory standards. For this reason, a ford taurus car representing a typical sedan has been considered as a medium. The simulation tests are conducted for the full frontal impact, small offset overlap impact and oblique impact configurations. A car interior environment is developed in MADYMO code, in which the human and dummy models are placed in. The acceleration acquired from the finite element analysis of frontal crash scenarios and the driver seat node are then input into the MADYMO code for both human and dummy models, and their kinematic responses are then compared. Per regulations, chest injury is considered to be a prominent factor in frontal crashes. Hence, the variations of chest deflection, chest acceleration and viscous criteria are investigated. The results from this study illustrate the potential difference between the human and dummy dynamic performances in various frontal crash scenarios. In particular, the differences in chest acceleration, chest deflection, and flexibility of spine are quantified.