Rollover, ROPS and FOPS Analysis of Vehicle Structures


ROPS and FOPS Analysis of Vehicle Structures is carried out for a big class of industrial machinery designed to work in dangerous work environments where falling down objects, debris etc., impact vehicle structures and rolling-over accidents may also happen. This type of heavy machinery are mainly used in construction, mining, and forestry industry.

The ability to test field service conditions in dangerous work areas and simulate these conditions leads to optimized load bearing structures in automotive and allied applications. For better safety of a driver or operator, mining, agricultural and self-propelled machines are equipped with protective structures

AdvanSES provides facilities and FEA simulation to conduct experimental ROPS, FOPS tests, and ROPS and FOPS Analysis of Vehicle Structures in the automotive, forestry, mining and construction related machinery.


FOPS stands for Falling Object Protective Structure. FOPS are protective devices structure designed to protect operators from items that may fall on a vehicle or machinery when it is being operated. The recognized standard to define the performance requirements for FOPS is ISO 3449 Earth moving machinery – Falling object protective structures. This standard is referenced in other standards for machineries in general also.

ISO 3449:2005 specifies laboratory tests for measuring the structural characteristics of, and gives performance requirements in a representative test for, falling-object protective structures (FOPS) intended for use on ride-on earth-moving machines as defined in ISO 6165. It is applicable to both FOPS supplied as an integral part of the machine and those supplied separately for attachment onto the machine.

There are two (2) different levels of FOPS – Level 1 & Level 2.

ISO 3449 states the following –

Level I impact protection –
Impact strength for protection from small falling objects (e.g. bricks, debris, small rocks) encountered in operations such as highway maintenance, and construction site services.
Level II impact protection –
Impact strength for protection from heavy falling objects (e.g. boulders, rocks) for machines involved in site clearing, mining and overhead demolitions.

Level I – withstands 1,365 joules (45kgs Fall at 3.1m drop)

Level II – withstands 11,600 joules (227 kgs Fall at 5.2m drop)

According to the standard, the weight is let to fall freely onto the vehicle cabin roof ceiling from a definite height. The weight is made of steel or cast steel with a cylindrical or spherical shape. The height of free fall in correlation with the mass of the weight has to provide the impact energy. The levels of energy depend on purpose of the structure. In the current project virtual testing has been carried out for the FOPS using the commercial software package Abaqus®.

Figures show the impactors and striker geometry prescribed in the standard for evaluating the vehicle structure.


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