Assessing the safety provided by SAE J2194 Standard and Code 4 Standard code for testing ROPS, using finite element analysis

Abstract

Society of Automotive Engineers (SAE) J2194 Standard and Code 4 tests are defined by parameters depending on a reference mass, usually the unladen mass of the tractor. As overturn energy is proportional to mass, and the maximum permissible mass of tractors has greatly increased in recent years, is now possible that these standards do not provide enough safety for highly laden vehicles. A finite element (FE) analysis program was used to develop a procedure to calculate the maximum reference mass in the equations that define the energies to be absorbed by roll-over protective structure (ROPS), during loading tests, and the forces to be exerted during crushing tests. Thus, the validity of the Code 4 and SAE J2194 Standard were examined. A test procedure was carried out using four tractor models. The cause of the test failure was, in all four cases, the collapse of the ROPS before it infringed the clearance zone. It was shown that the current codes provide sufficient safety margins for only three of the four tractor models tested. The tests demonstrated that FE methods can be used to design safer ROPS.