Measurement and quantification of road induced shock severity on lumbar spine of seated occupants

The objective of current work is to measure and quantify the severity of road/surface induced shocks in relation to human health as per guidelines given in ISO 2631-5:2004. Additionally, to develop a MATLAB routine for the recommended procedure, assisting to arrive at safe operational duty cycle for drivers operating on selected road surfaces. To start with, vibration levels experienced by driver are measured by conducting road trials using an instrumented SUV. Responses at the seat cushion location are measured at all test surfaces for two consecutive runs. Using the recommended predictive models (as implemented in routine), the acceleration dose values are calculated. Further, the equivalent static compressive stress, calculated from obtained values of acceleration dose, is used to assess health effects on human body. Through extrapolation, a safe operational duty cycle is obtained for the drivers operating on a Belgian pave 1 and 2, high frequency track, off-road and country road. Results show that the Belgian pave 1 and 2 are most hazardous to the driver, whereas off-road is found to be the least hazardous at test speed considered.