Roll Over Protection System (ROPS) Development
Under the watchful eye of FIA Institute research consultant Andy Mellor, four Subaru Impreza’s, each with different variations of steel used for it’s roll cage construction, have been slammed into a test rig in the UK based Millbrook development facility.
Two years in the making, these precisely calibrated collisions will test potential improvements to the roll-over protection (ROPS) system fitted to competition rally cars, and will provide valuable data to better understand the balance between the strength of roll cage design versus it’s need to manage energy absorption whilst deforming.
Controlling intrusion is obviously desirable in a roll-over, however energy management between drivers and an impact point, such as a tree, is also critical. Prodrive Technical Director, David Lapworth who oversaw the construction of the cars says, “during a roll-over accident you must limit intrusion of the roof to avoid direct contact with the driver’s helmets, this requires both strength and energy absorption from the cage”.
Above Left: One of Four roll cage prepared Subaru Impreza’s loaded with sensors, potentiometers and accelerometers, prepares to be fired roof first at the impact target Above Right: Key components of the test were to study both the strength and energy absorption characteristics of commonly used roll cage materials, along with information around different welding methods and failure paths.
The four steels used as part of the test were T45 and15CDV6, both higher performance steels typically used for World Rally Cars. In addition, ROPT 510 and CDS were also tested – lower strength but more ductile materials often targeted at club racing.
The test is looking for strong materials with compliant joints which will deform. Mellor states “ideally, we want the cage to deform by up to 400mm without any joints in the cage failing.
Importantly, the study and further deep analysis will also provide an insight into the TIG and MIG welding solutions that bind the sections of steel tube together. In addition, the data captured by the four cars covered in sensors, accelerometers and potentiometers, will allow an understanding of the the sequence of failure within the various roll cages.
“Once we have all the results,” says Mellor, “we will go away and look at the [ROPS] design and most likely take that on to the next phase of research”.
Ultimately, results from this test and ongoing research will further help define the FIA’s current technical regulations regarding ROPS.
(Click Button Below To Read The Full ROPS Story…)