Effect of lateral stiffness coefficient of loader ROPS on human injury in a lateral rollover incident

In engineering and agricultural machinery, rollover protective structures (ROPS) are widely used to protect the driver during rollover accidents. In the existing international standards, ROPS performance is verified by a static test and ROPS are often designed according to the finite element method. In this paper, a dynamic analysis of the loader ROPS was conducted to verify the effectiveness of the ROPS during a dynamic rollover incident. Moreover, the concept of lateral stiffness coefficient (LSC) was proposed. The human injury mechanism is used to evaluate the impact on human injury through the LSC of the ROPS during the dynamic rollover process. Six ROPSs with different LSC were designed based on the static test criteria and dynamically simulated by using the Mathematical Dynamic Models software MADYMO. Based on the simulations and the tests, the ROPS met the standard but could not protect the operator from injury. The dynamic simulation method is also suitable for designing safer ROPS. In conclusion, ROPS with appropriate LSC could reduce body injuries; however, the exact LSC values are not identical among different types of ROPS.