Malibu | Malibu Testing

Donald Friedman concluded that the Malibu test series could resolve the question of causal relationship between roof crush and injury and determined from the data that the incidence of severe head and neck injury in production cars was two to three times more likely than in rollcaged cars. Friedman found three severe head and neck injuries in production vehicles and none in rollcaged vehicles. He determined that severe head and neck injury was causally related to the velocity and extent of roof crush.

Carl Nash concluded that in the first Malibu series, the dummies sustained numerous head impacts with upper neck forces between 2,000 and 6,000 N. Since the dummies were all unbelted in this series, they were mostly out of position by the time the roof crushed in the second or third roll. Only two impacts were sufficiently severe to injure a human head or neck. Both were in the cars with unreinforced roofs and both coincided with major collapse of the vehicle’s roof.

In the second Malibu test series all dummies were safety belted. The belts held them in their seating positions, so that their heads were positioned near the roof rail where they were more likely to receive blows from the collapsing and buckling roofs of these cars. The four head impacts in which the force on the neck exceeded 7,000 N were again all in cars without roll cage reinforcements. They ranged from 7,500 to 13,300 N.

The dummy does not suffer injury producing forces if the roof does not collapse. Click to read full paper...

Nash further explains that...

The understanding of causal relationship between roof crush and head-neck injury was different in the mid seventies when the diving theory was proposed by General Motors or to be specific by their employee Moffatt [ 81. This non-quantified theory that described the way occupants attributed injuries in rollover was flawed from start. To satisfy the management, General Motors test engineers decided to experimentally test Moffatt’s theory in 1983 [9] and again in 1987 [lo]. These tests became to be known as Malibu I & I1 and they have ever since influenced roof designs of most cars on the road today based on the following misconstrued specific outcomes from the test results presented in [9] and [lo]: Roof deformation is not related to injury severity. This is now known to be based on diving theory that is flawed. There is no correlation between roof crush and injurious biomechanical loads. This is now known to be based on poor interpretation of results that they did not understand. When the roof contacts the ground, peak neck compression loads occur prior to any substantial roof deformation. This is not correct, because it is now known that roof acceleration peaked precisely at the same time as the neck load and the velocity was greater than zero. Research to date has found that roof crush is not causally related to injuries in typical rollover crashes. Not correct, because research has found that roof intrusion is causally related to injuries if results are properly interpreted. In this paper, forensic methodologies are used on Malibu results together with some mathematical operations to show that there is 100% causally relationship between roof intrusion and occupant injuries. Click to read full paper...