PROBABILISTIC ASSESSMENT FOR CLAVICLE FRACTURE UNDER COMPRESSION LOADING: RATE-DEPENDENT BEHAVIOR

Abstract

Pedestrians, motorcyclists, and occupants of vehicle involved in side impacts can suffer lateral impacts at the shoulder with sufficiently high forces to fracture the clavicle. While some previous studies have developed a force tolerance for the clavicle, this study examines the clavicle under compression forces, both under dynamic and quasi-static loading conditions and then the experimental fracture patterns are compared with those identified in actual road traffic crashes. The quasi-static and dynamic tests were conducted in 24 clavicles from 14 donors aged 14–56 (11 males and 3 females, mean age [Formula: see text]). Clavicles were tested under compression forces until complete fracture. Probability of fracture is around 50% for 2335[Formula: see text]N in the quasi-static case (low strain rate) and 3045[Formula: see text]N in the dynamic case (high strain rate). In addition, risk curves for fracture have been computed from the sample. The experiments showed large differences in the peak force both in quasi-static ([Formula: see text][Formula: see text]N) and dynamic ([Formula: see text][Formula: see text]N) tests, but the displacement at the peak force was very similar ([Formula: see text][Formula: see text]mm in quasi-static and [Formula: see text][Formula: see text]mm in dynamic tests). Thus, a stiffer behavior of the specimens was observed for the dynamic tests. The Probability Density Function for dynamic and quasi-static cases differ significantly ([Formula: see text]-value [Formula: see text]). The fracture patterns were consistent with principles of structural mechanics, predicting that the fracture will occur at points near to the highest bending moment point, and with the fractures observed in real road crashes.