The research of this thesis was performed to understand the vibrational dynamics of stage 0&1 child safety seats and of the children who occupy them. Since no previous vibration data for small children or child seats was found, the investigation took the form of experiments designed to shed light on the behaviour of the system consisting of child, child seat, vehicle safety belt and vehicle seat. To provide a background for interpreting the results a literature review was performed of child seat characteristics, of human whole-body response and of primate whole-body response. An industrial test procedure for measuring the vibration isolation properties of vehicular seats is also presented as an illustration of the concepts involved. A whole-body vibration bench for testing children in the vertical direction was built and apparent mass and absorbed power functions were measured for 8 children of age less than 24 months and mass less than 13 kg. An algorithm was developed for identifying the parameter values of a single degree of freedom mass-spring-damper model of the seated body using Differential Evolution optimisation. The parameter values were determined for each child and compared to those of adults and primates. This thesis also presents the results of modal testing of 2 child seat units and of operational deflection shape testing of 1 unit in an automobile under 3 loading conditions (empty, sandbag or child). In-vehicle transmissibility measurements were also performed in the vertical direction for 10 children and child seats using 9 automobiles. The floor-to-human transmissibilities were determined for each child and driver when passing over a reference road surface at both 20 and 40 km/h. Except for the damping ratio, all child mechanical response parameters were found to differ with respect to those of adults or primates, with the differences being greater with respect to adults. The first resonance frequency of children was found to be located at 8.5 Hz as opposed to 4.0 Hz for adults, raising questions regarding the applicability of standards such as ISO 2631 towards the evaluation of child vibrational comfort. The child seats were found to have higher transmissibilities on average than the vehicular seats occupied by adults. A characteristic low frequency rigid body rocking motion was noted at 1.8 Hz as were multiple flexible body resonances starting from frequencies as low as 15 Hz. Areas of possible improvement and topics for further research have been identified.

"Reprint from Master Thesis at Linköpings universitet in cooperation with The Swedish National Road and Transport Research Institute (VTI). LiTH-IKP-Ex2041." / Includes bibliographical references (p. 89-90). Also available online via the Swedish National Road and Transport Research Institute web site (www.vti.se).

Thesis (Ph.D. in Engineering)--Technischen Universität Berlin, 2007. / "Juni 2008"--P. [2]. Includes abstracts in English and German. Includes bibliographical references (p. 127-129). Abstract in English also available online.

Thesis (M.Sc.)--York University, 2007. Graduate Programme in Kinesiology and Health Science. / Typescript. Includes bibliographical references (leaves 61-67). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&res_dat=xri:pqdiss&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&rft_dat=xri:pqdiss:MR31992

The primary intervention for injury in children traveling in cars in Australia has involved the mandatory use of a restraint while traveling in a vehicle. This intervention has been successful as evidenced by high restraint usage rates by Australian children and substantial casualty reductions since the 1970’s. However casualty rates have been relatively stagnant over the last couple of decades. Currently more than 3,000 child occupants are seriously injured in Australia every year. There is a need to examine the scope for further preventing injury among restrained child occupants. This thesis presents four interrelated studies examining the factors and mechanisms involved when Australian children are seriously injured while using some form of restraint in a crash. Methods used include retrospective medical record review, in-depth crash investigation and analysis of mass in-depth crash data. Both descriptive and nonparametric statistical analysis techniques, including those that allow for the control of potential confounders, were used. Observations and results indicate there is substantial scope for further reducing serious injury in children traveling in cars in Australia. To realize this reduction there is a need to address the quality of restraint use by children through the development of strategies that not only encourage restraint use, but encourage the correct use of the most appropriate forms of restraint. There is also a need to address the protection provided by restraint systems and vehicles to child occupants in high severity crashes, and in crashes that involve impacts with fixed roadside objects such as trees and poles.

The primary intervention for injury in children traveling in cars in Australia has involved the mandatory use of a restraint while traveling in a vehicle. This intervention has been successful as evidenced by high restraint usage rates by Australian children and substantial casualty reductions since the 1970’s. However casualty rates have been relatively stagnant over the last couple of decades. Currently more than 3,000 child occupants are seriously injured in Australia every year. There is a need to examine the scope for further preventing injury among restrained child occupants. This thesis presents four interrelated studies examining the factors and mechanisms involved when Australian children are seriously injured while using some form of restraint in a crash. Methods used include retrospective medical record review, in-depth crash investigation and analysis of mass in-depth crash data. Both descriptive and nonparametric statistical analysis techniques, including those that allow for the control of potential confounders, were used. Observations and results indicate there is substantial scope for further reducing serious injury in children traveling in cars in Australia. To realize this reduction there is a need to address the quality of restraint use by children through the development of strategies that not only encourage restraint use, but encourage the correct use of the most appropriate forms of restraint. There is also a need to address the protection provided by restraint systems and vehicles to child occupants in high severity crashes, and in crashes that involve impacts with fixed roadside objects such as trees and poles.

Orientadores: Antonio Celso Fonseca de Arruda, Paulo Roberto Gardel Kurka / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica / Made available in DSpace on 2018-08-14T02:53:31Z (GMT). No. of bitstreams: 1 Jorge_AlexandreFonseca_M.pdf: 2455128 bytes, checksum: 714a30d7c2214aa6edc9a048f74aa56d (MD5) Previous issue date: 2006 / Resumo: Um dispositivo de retenção infantil, a ser certificado pela norma NBR14400, tem como um dos principais requisitos atingir determinados níveis de performance em ensaios de impacto. Durante seu desenvolvimento, o dispositivo deve ser submetido a esse teste várias vezes, até ser aprovado, o que envolve altos custos. Este estudo propõe um teste de impacto simplificado, não para substituir o teste de certificação, mas na condição de teste de desenvolvimento preliminar e eliminatório. O principal equipamento envolvido, neste estudo, é o boneco de testes, que possui simplificações tanto na parte biomecânica quanto na parte de instrumentação. Como vantagem, quando comparado ao boneco instrumentado completo, seu custo é significativamente menor. Neste trabalho são apresentadas as condições de contorno envolvidas no projeto, na construção e no uso desse boneco. Adicionalmente, são reportados os resultados comparativos dos ensaios de impacto entre o boneco construído e o instrumentado completo Hybrid III. Tais resultados validam a proposta do projeto / Abstract: A child restraint system, to be certified to NBR 14400 standard, has as one of its main requirements, to reach specific performance levels under impact tests. During its development, the device has to undergo several times such tests, which are expensive, until approval. This study proposes a simplified impact test, not to replace the certification test, but as a preliminary and eliminatory test. The main equipment involved in this study is the test dummy, which has simplifications both on biomechanical and instrumentation aspects. As an advantage, when compared to a complete instrumented dummy, it has a considerably lower cost. In this work, the guiding conditions involved in the project, construction and use of that dummy are presented. Also, the results of comparative impact testes between the projected dummy and the complete instrumented dummy Hybrid III are reported. Such results validate the proposal of the project / Mestrado / Mestre em Engenharia Mecânica

Orientador: Antonio Celso Fonseca de Arruda / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-26T12:30:34Z (GMT). No. of bitstreams: 1 Souza_VictorCesarde_M.pdf: 2933493 bytes, checksum: ad3ab87009ea90dcb39a5fd7757c4c9a (MD5) Previous issue date: 2015 / Resumo: Projeto, construção e avaliação de desempenho de simulador de testes de impacto de dispositivos de retenção infantis. A solução construtiva objetivou simular uma colisão automobilística e utiliza manequins representativos de crianças para fins de efeito demonstrativo e de convencimento sobre a necessidade de se reter crianças em veículos automotores. Trata-se de um trenó, guiado, que se desloca sobre trilhos sendo tracionado por cabo de aço e, capaz de, sem dano permanente, colidir contra uma barreira de impacto deformável. O equipamento foi concebido para fácil instalação em locais públicos e utiliza motor de indução para tracionar o cabo de aço e sistemas de automatização de aferição da velocidade, de aceleração e parada do motor. A instrumentação eletrônica utilizada na montagem do simulador permite avaliação do desempenho do equipamento para velocidades de até 20 Km/h / Abstract: Design, construction and evaluation of impact tests simulator performance of child restraint systems. The constructive solution aimed to simulate an automobile collision and uses dummies representing children for the purposes of demonstration effect and conviction about the need to retain children in motor vehicles. This is a sled, guided, moving on rails being pulled by steel cable and capable of, without permanent damage, crash into a deformable barrier impact. The equipment is designed for easy installation in public places and induction motor uses to pull the cable and speed measurement automation systems, acceleration and engine stop. The electronic instrumentation used in the simulator assembly allows assessment of equipment performance for speeds up to 20 km / h / Mestrado / Materiais e Processos de Fabricação / Mestre em Engenharia Mecânica