2026-09-21T21:46:37Zhttps://dspace.mit.edu/server/oai/request

oai:dspace.mit.edu:1721.1/653102022-01-13T07:54:36Zcom_1721.1_7582com_1721.1_7581col_1721.1_131023

Lorna J.Gibson. Matton, Yves, S.M. Massachusetts Institute of Technology Massachusetts Institute of Technology. Dept. of Mechanical Engineering. Massachusetts Institute of Technology. Department of Mechanical Engineering 2011-08-18T19:16:54Z 2011-08-18T19:16:54Z 2011 2011 http://hdl.handle.net/1721.1/65310 745775873 Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011. Cataloged from PDF version of thesis. Includes bibliographical references (p. 259-268). The development of new threats in recent conflicts, such as improvised explosive devices (IEDs), requires the development of improved protection for US soldiers. The development of improved materials for helmets, in particular, is motivated by the social and economic costs of head injury. A versatile liner, adaptable to different types of helmets, with different constraints, would be useful. In this thesis, we first review the statistics related to head injuries from motor vehicle and recreational accidents and then describe the state of the art of current helmet design. An experimental study of the response of a widely used helmet liner material (polystyrene foam) and a new potential liner material (low-density, reticulated, elastomeric foam impregnated with Newtonian and non-Newtonian fluids) under impact shows some complementarities and leads to the concept of a composite material that would take advantage of the properties of the two materials. To conduct an extensive design analysis, comprehensive models are developed to model the behavior of each material under a wide range of impact energies. A complete model for the composite bilayer of the two materials is then compared to experimental data; the model gives a good description of the data. Using these results, three case studies are developed for a motorcycle helmet, a football helmet and a military helmet. The three case studies show a variety of constraints in term of thickness of the liner and impacting energies. Simulations are conducted using the models developed to indentify potential designs that would meet the requirement in term of peak linear acceleration (PLA) and in term of the specific constraints of each type of helmet. Finally, in an experimental study, some of the proposed designs are tested for repeated loading. The proposed designs enhance the level of protection in term of peak linear acceleration and show promising behavior under repeated impact testing. by Yves Matton. S.M. 268 p. eng Massachusetts Institute of Technology M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission. http://dspace.mit.edu/handle/1721.1/7582 Mechanical Engineering. Use of low-density, reticulated, elastomeric foam impregnated with Newtonian and non-Newtonian fluids to design an impact absorption material Thesis application/pdf false Publication unknown unknown <Publication xmlns="https://www.openaire.eu/cerif-profile/1.1/" id="67199f1e-d7ca-4829-8997-d6132f4f3e44"> <Type xmlns="https://www.openaire.eu/cerif-profile/vocab/COAR_Publication_Types">http://purl.org/coar/resource_type/c_1843</Type> <Language>eng</Language> <Title>Use of low-density, reticulated, elastomeric foam impregnated with Newtonian and non-Newtonian fluids to design an impact absorption material</Title> <PublishedIn> <Publication> </Publication> </PublishedIn> <PublicationDate>2011</PublicationDate> <Authors> <Author> <DisplayName>Matton, Yves, S.M. Massachusetts Institute of Technology</DisplayName> <Affiliation> <OrgUnit> </OrgUnit> </Affiliation> </Author> </Authors> <Editors> </Editors> <Publishers> <Publisher> <DisplayName>Massachusetts Institute of Technology</DisplayName> <OrgUnit /> </Publisher> </Publishers> <License>http://dspace.mit.edu/handle/1721.1/7582</License> <Keyword>Mechanical Engineering.</Keyword> <Abstract>The development of new threats in recent conflicts, such as improvised explosive devices (IEDs), requires the development of improved protection for US soldiers. The development of improved materials for helmets, in particular, is motivated by the social and economic costs of head injury. A versatile liner, adaptable to different types of helmets, with different constraints, would be useful. In this thesis, we first review the statistics related to head injuries from motor vehicle and recreational accidents and then describe the state of the art of current helmet design. An experimental study of the response of a widely used helmet liner material (polystyrene foam) and a new potential liner material (low-density, reticulated, elastomeric foam impregnated with Newtonian and non-Newtonian fluids) under impact shows some complementarities and leads to the concept of a composite material that would take advantage of the properties of the two materials. To conduct an extensive design analysis, comprehensive models are developed to model the behavior of each material under a wide range of impact energies. A complete model for the composite bilayer of the two materials is then compared to experimental data; the model gives a good description of the data. Using these results, three case studies are developed for a motorcycle helmet, a football helmet and a military helmet. The three case studies show a variety of constraints in term of thickness of the liner and impacting energies. Simulations are conducted using the models developed to indentify potential designs that would meet the requirement in term of peak linear acceleration (PLA) and in term of the specific constraints of each type of helmet. Finally, in an experimental study, some of the proposed designs are tested for repeated loading. The proposed designs enhance the level of protection in term of peak linear acceleration and show promising behavior under repeated impact testing.</Abstract> <Access xmlns="http://purl.org/coar/access_right" > </Access> </Publication>