Bicycle helmet retention system testing and evaluation

摘要

Bicycle helmet testing is conducted under laboratory conditions, which do not always reflect real-world conditions. This paper reports on a survey of chin strap use among a test group of bicycle riders and the results of three tests: (1) a retention harness system static test to determine elongation properties; (2) a loop and position device test to determine the effects of the combination of the webbing positioner and the elongation properties of the webbing; and (3) a dynamic test to demonstrate the compatibility of the helmet retention system under real-world type dynamic impact loading conditions. The survey showed that bicyclists wear their helmets with an average of 4.76 cm of strap clearance when tested with a 500 gram load. Tests of chin strap shows that substantial motion and elongation can occur under nominal loading conditions. Comparative dynamic testing resulted in a bicycle helmet rotating forward significantly and exposing the back of the dummy head, while an equestrian helmet with a different retention system design rotated only slightly forward and remained on the dummy head. These tests demonstrate that effective helmet retention testing must take into account consumers' normal use of helmets, and how all the elements in the helmet and its retention system work together.