Finite Element Analysis of a Two-Post Rollover Protective Structure of an off-Highway Motor Grader

Rollover protective structure (ROPS) is a critical safety system mounted on off-highway equipments, which serves as a safety structure for an operator survival during rollover accidents. ROPS is classified as single post, two post, four post, and multi-post; selection of this ROPS depends on the type of the application. Commonly used off-highway equipments are dump truck, articulated scrapers, dozers, water sprinklers, excavators, loaders, motor grader, etc.; among these equipments, motor graders were extensively used in off-highway and mining works. It is noticed from the accidents summary reported by the Directorate General of Mine and Safety, India, and Occupational Safety and Health Administration (OSHA), USA, that a significant failure was noticed by the motor grader ROPS structure. Hence, it is necessary to study the failure behavior and strength criteria of rollover protective structure. In the present research work, attempts are made to study the failure behavior and strength of a two-post motor grader (25 tons GVW) ROPS using finite element analysis (FEA) software ANSYS. Further, an interlock section was introduced in the ROPS column to minimize the overall size and to enhance the performance of the ROPS. Later, comparative analysis has been done on this ROPS in terms of maximum deformation, rate of energy absorption, and C.G height. It is evident from the results that proposed ROPS has 30% reduction in overall size, 5% reduction in weight, and enhanced C.G of height. Further, the proposed ROPS meets the performance requirement of existing standards.