Passive safety of operators of earthmoving machines

Abstract

Falling objects and roll over earthmoving machines are a huge hazard and a major cause of accidents. Safety structures called FOPS (Falling Object Protective Structures) and ROPS (Roll Over Protective Structures) have been used to protect the operators. A FOPS and ROPS cabin should withstand the loads and consume energy during accidents. FOPS and ROPS standards require full scale destructive testing to validate its conformity with the requirements, at present. This is caused due to a lack of fundamental research information on the nonlinear inelastic response of the cabs structures. However, a non-linear, static or dynamic, finite element analysis (FEA) has been used to simulate the FOPS/ROPS testing. The FEA results have been compared with those of experimental testing and the FEA methodology has been improved to get a good correlation. The FEA approach will be used to finalize the FOPS/ROPS design prior to full scale testing to minimize the number of prototype and thereby, to reduce the development cost and time. This paper presents the FEM as sufficiently verified method for both tests, FOPS and ROPS, at the first step of the design process. The accuracy of the mapping of the object with the model adopted for the simulation has a primary impact on the convergence of calculations with test results. This applies both to its geometry, the accepted loads and to the mechanical properties of the materials used.

This is an Open Access article distributed under the terms of the Creative Commons Attribution License CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/)