Post-accident evidence basis for new equestrian standards: Relationship between helmet liner residual crush and accident parameters
An in-depth analysis of 216 equestrian helmets involved in real-world accidents, with accompanying laboratory drop-test experiments has focussed on the crushing of energy absorbing liners. The mean measured residual crush (i.e., damage in the form of permanent deformation of helmet liner expressed a...
| Main Authors: | , , , , |
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| Format: | Article |
| Language: | English |
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Elsevier
2021-06-01
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| Series: | Applications in Engineering Science |
| Subjects: | |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S2666496821000108 |
| _version_ | 1818691131502755840 |
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| author | Thomas A. Connor J. Michio Clark Matt Stewart Aisling Ní Annaidh Michael D. Gilchrist |
| author_facet | Thomas A. Connor J. Michio Clark Matt Stewart Aisling Ní Annaidh Michael D. Gilchrist |
| author_sort | Thomas A. Connor |
| collection | DOAJ |
| description | An in-depth analysis of 216 equestrian helmets involved in real-world accidents, with accompanying laboratory drop-test experiments has focussed on the crushing of energy absorbing liners. The mean measured residual crush (i.e., damage in the form of permanent deformation of helmet liner expressed as a percentage of the local undeformed thickness) was 21.5%. For front, rear and side impacts that occurred against both rigid and soft surfaces, the amount of residual crush varied linearly with impact velocity, peak translational acceleration, and maximum dynamic crush. For all impact locations, the percentage of energy absorbed by the helmet during an impact with a rigid surface is significantly less (between 4% and 20%) than those of both un-helmeted and helmeted headform soft surface impacts. Thus, the amount of helmet residual crush provides important insight into real-world equestrian accidents. This approach provides an evidence basis to improve future certification standards. There is clear scope to improve helmet designs, as helmet performance is clearly not optimised either for impact against soft surfaces or for relatively low velocity impacts. We suggest a peak impact power threshold that would improve equestrian helmet energy absorption for soft surface impacts without altering current standard test methodologies. |
| first_indexed | 2024-12-17T12:37:01Z |
| format | Article |
| id | doaj.art-6f521c0935e54c8bae74d8f6b59691ea |
| institution | Directory Open Access Journal |
| issn | 2666-4968 |
| language | English |
| last_indexed | 2024-12-17T12:37:01Z |
| publishDate | 2021-06-01 |
| publisher | Elsevier |
| record_format | Article |
| series | Applications in Engineering Science |
| spelling | doaj.art-6f521c0935e54c8bae74d8f6b59691ea2022-12-21T21:48:14ZengElsevierApplications in Engineering Science2666-49682021-06-016100044Post-accident evidence basis for new equestrian standards: Relationship between helmet liner residual crush and accident parametersThomas A. Connor0J. Michio Clark1Matt Stewart2Aisling Ní Annaidh3Michael D. Gilchrist4School of Mechanical & Materials Engineering, University College Dublin, , Dublin 4, Belfield, Ireland; COMFG Ltd. (Charles Owen), Royal Works, Croesfoel Ind. Park, Wrexham LL14 4BJ, United Kingdom; R&D Consulting Engineers Ltd., Leeds LS17 6AF, United KingdomSchool of Mechanical & Materials Engineering, University College Dublin, , Dublin 4, Belfield, Ireland; Vector Scientific Inc., Golden 80403, CO, United StatesCOMFG Ltd. (Charles Owen), Royal Works, Croesfoel Ind. Park, Wrexham LL14 4BJ, United KingdomSchool of Mechanical & Materials Engineering, University College Dublin, , Dublin 4, Belfield, IrelandSchool of Mechanical & Materials Engineering, University College Dublin, , Dublin 4, Belfield, Ireland; Corresponding author.An in-depth analysis of 216 equestrian helmets involved in real-world accidents, with accompanying laboratory drop-test experiments has focussed on the crushing of energy absorbing liners. The mean measured residual crush (i.e., damage in the form of permanent deformation of helmet liner expressed as a percentage of the local undeformed thickness) was 21.5%. For front, rear and side impacts that occurred against both rigid and soft surfaces, the amount of residual crush varied linearly with impact velocity, peak translational acceleration, and maximum dynamic crush. For all impact locations, the percentage of energy absorbed by the helmet during an impact with a rigid surface is significantly less (between 4% and 20%) than those of both un-helmeted and helmeted headform soft surface impacts. Thus, the amount of helmet residual crush provides important insight into real-world equestrian accidents. This approach provides an evidence basis to improve future certification standards. There is clear scope to improve helmet designs, as helmet performance is clearly not optimised either for impact against soft surfaces or for relatively low velocity impacts. We suggest a peak impact power threshold that would improve equestrian helmet energy absorption for soft surface impacts without altering current standard test methodologies.http://www.sciencedirect.com/science/article/pii/S2666496821000108Equestrian accidentImpact surfaceHelmet stiffnessEPS foamResidual crush |
| spellingShingle | Thomas A. Connor J. Michio Clark Matt Stewart Aisling Ní Annaidh Michael D. Gilchrist Post-accident evidence basis for new equestrian standards: Relationship between helmet liner residual crush and accident parameters Applications in Engineering Science Equestrian accident Impact surface Helmet stiffness EPS foam Residual crush |
| title | Post-accident evidence basis for new equestrian standards: Relationship between helmet liner residual crush and accident parameters |
| title_full | Post-accident evidence basis for new equestrian standards: Relationship between helmet liner residual crush and accident parameters |
| title_fullStr | Post-accident evidence basis for new equestrian standards: Relationship between helmet liner residual crush and accident parameters |
| title_full_unstemmed | Post-accident evidence basis for new equestrian standards: Relationship between helmet liner residual crush and accident parameters |
| title_short | Post-accident evidence basis for new equestrian standards: Relationship between helmet liner residual crush and accident parameters |
| title_sort | post accident evidence basis for new equestrian standards relationship between helmet liner residual crush and accident parameters |
| topic | Equestrian accident Impact surface Helmet stiffness EPS foam Residual crush |
| url | http://www.sciencedirect.com/science/article/pii/S2666496821000108 |
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