The objective of this paper is to highlight the chest deflection measurement approach that was implemented in the Hybrid III dummy, and to present detailed results obtained in the Association des Constructeurs Europeens d'Automobiles (ACEA) research programme. During the static and pendulum tests, when the loadings to the chest have been moderate, the standard rod and the string potentiometers appeared to function without any obvious faults. In sled tests using different restraint systems, dummy locations and sled pulses, the string potentiometer seemed to function well, but the rod potentiometer has failed in a few cases. A general observation from all tests is, that the rod potentiometer in the large potentiometer in the large majority of cases shows an about 10 mm higher displacement than the one measured at the ends of the ribs. Concerning reliability, the data obtained support the string potentiometer approach for chest deflection measurement on the Hybrid III dummy. Even attached to the ribs, with more variations in load transfer, the string potentiometer showed acceptable repeatability. It is proposed to replace the standard rod potentiometer by a string potentiometer, using identical mounting position, in order to solve the chest deflection issue. (A)
Abstract