An analytical method for calculating roof stiffness factors from roof performance during dynamic and quasi-static loading tests

摘要

Additional test data from static roof strength tests and inverted vehicle drop tests are combined with previous work conducted by Rains (1) to establish a correlation between roof stiffness characteristics under dynamic versus static loading conditions. From this expanded data set, roof stiffness factors are developed based upon the energy absorption characteristics of the structure and an alternative dynamic vs. static correlation is developed. Two equations are derived based upon vehicle class. Class one is made up of light trucks, vans, and sport utility vehicles, while class two includes all other passenger cars. The methodology developed allows designers, researchers and crash investigators to, based upon widely available static roof strength data, predict roof stiffness and crush resistance under dynamic loading conditions. Prediction of an equivalent drop height and impact velocity is also made possible given residual static crush profiles and static roof strength test data.