Purpose:The current study aimed to assess the protective performance of helmets equipped with multidirectional impact protection system(MIPS)under various oblique impact loads.Methods:Initially,a finite element model ...Purpose:The current study aimed to assess the protective performance of helmets equipped with multidirectional impact protection system(MIPS)under various oblique impact loads.Methods:Initially,a finite element model of a bicycle helmet with MIPS was developed based on thescanned geometric parameters of an actual bicycle helmet.Subsequently,the validity of model wasconfirmed using the KASK WG11 oblique impact test method.Three different impact angles(30°,45°,and 60°)and 2 varying impact speeds(5 m/s and 8 m/s)were employed in oblique tests to evaluateprotective performance of MIPS in helmets,focusing on injury assessment parameters such as peaklinear acceleration(PLA)and peak angular acceleration(PAA)of the head.Results:The results demonstrated that in all impact simulations,both assessment parameters werelower during impact for helmets equipped with MIPS compared to those without.The PAA wasconsistently lower in the MIPS helmet group,whereas the difference in PLA was not significant in the noMIPS helmet group.For instance,at an impact velocity of 8 m/s and a 30°inclined anvil,the MIPS helmetgroup exhibited a PAA of 3225 rad/s^(2) and a PLA of 281 g.In contrast,the no-MIPS helmet group displayeda PAA of 8243 rad/s^(2) and a PLA of 292 g.Generally,both PAA and PLA parameters decreased with theincrease of anvil angles.At a 60°anvil angles,PAA and PLA values were 664 rad/s^(2) and 20.7 g,respectively,reaching their minimum.Conclusion:The findings indicated that helmets incorporating MIPS offer enhanced protection againstvarious oblique impact loads.When assessing helmets for oblique impacts,the utilization of larger angleanvils and rear impacts might not adequately evaluate protective performance during an impact event.These findings will guide advancements in helmet design and the refinement of oblique impact testprotocols.展开更多
基金This work was supported by the Natural Science FoundationProject of Xiamen City,China(3502Z20227223)Fujian Provincial Technological Innovation Key Research and IndustryDevelopment Project(2022G43)and(2023G048).
文摘Purpose:The current study aimed to assess the protective performance of helmets equipped with multidirectional impact protection system(MIPS)under various oblique impact loads.Methods:Initially,a finite element model of a bicycle helmet with MIPS was developed based on thescanned geometric parameters of an actual bicycle helmet.Subsequently,the validity of model wasconfirmed using the KASK WG11 oblique impact test method.Three different impact angles(30°,45°,and 60°)and 2 varying impact speeds(5 m/s and 8 m/s)were employed in oblique tests to evaluateprotective performance of MIPS in helmets,focusing on injury assessment parameters such as peaklinear acceleration(PLA)and peak angular acceleration(PAA)of the head.Results:The results demonstrated that in all impact simulations,both assessment parameters werelower during impact for helmets equipped with MIPS compared to those without.The PAA wasconsistently lower in the MIPS helmet group,whereas the difference in PLA was not significant in the noMIPS helmet group.For instance,at an impact velocity of 8 m/s and a 30°inclined anvil,the MIPS helmetgroup exhibited a PAA of 3225 rad/s^(2) and a PLA of 281 g.In contrast,the no-MIPS helmet group displayeda PAA of 8243 rad/s^(2) and a PLA of 292 g.Generally,both PAA and PLA parameters decreased with theincrease of anvil angles.At a 60°anvil angles,PAA and PLA values were 664 rad/s^(2) and 20.7 g,respectively,reaching their minimum.Conclusion:The findings indicated that helmets incorporating MIPS offer enhanced protection againstvarious oblique impact loads.When assessing helmets for oblique impacts,the utilization of larger angleanvils and rear impacts might not adequately evaluate protective performance during an impact event.These findings will guide advancements in helmet design and the refinement of oblique impact testprotocols.
