Archives for : May2008

New Technologies Mean Better Rear Impact Performance

The Volvo XC60, a small size SUV, has been developed with several technologies designed to give it the edge in whiplash injury crash tests. Twenty five passenger cars were tested by EuroNCAP in their first round of whiplash tests. Five cars received top marks: Volvo XC60, Alfa Romeo Mito, Volkswagen Golf VI, Audi A4 and Opel Insignia.

A new assessment protocol has been implemented by EuroNCAP to evaluate whiplash protection provided by passenger cars in a rear-end collision. (EuroNCAP Rear Collision Tests.)

The new procedure includes several different tests. Firstly, a seat’s geometry is measured. The position/location of the passenger head restraint, for example, is measured to determine protection against injuries during a collision. Three further collision tests are then conducted in a rig, with varying degrees of severity. The rig simulates a situation where a stationary car is subjected to a rear-end impact. Finally, the results are gathered and evaluated and each car is graded on a colour scale where red is poor, orange is marginal and green is good.

The Volvo XC60 performed well in all of the tests and was given an overall rating of green and also received the highest rating of five stars in EuroNCAP’s Adult Occupant Protection tests, which include front and side impacts.

Whiplash injuries are one of the most common types of motor vehicle injury and happen primarily in rear-end impacts.

“The reason for neck injuries is the very rapid movement between the head and body,” explains Thomas Broberg, of Volvo. “This makes it vital for the whiplash protection system to support the entire back and head and to help the person’s head move together with the torso. The design of the seat’s backrest and a head restraint that is sufficiently high and positioned close to the head are also important factors.”

Volvo’s Whiplash Protection System (WHIPS) is a form of protection integrated into the front seats which is designed to support an occupant’s entire back and head in a rear-end collision. The WHIPS system cushions the movement during impact using energy-absorbing deformation elements between the backrest and seat cushion. When a rear-end collision occurs, the backrest follows the passenger’s rearward movement to reduce the forces on the neck and spine.
This technology was introduced in 1998 on the Volvo S80 and has been a standard feature on all Volvo models since 2000.

EuroNCAP Rear Impact Tests

Good

The occupant’s body is well supported, the seat helps to absorb energy of the impact.

Marginal

Differences are less obvious but the seat doesn’t appear to absorb as much energy as the ‘good’ example, the occupant travels further as the vehicle decelerates.
Poor

Poor

Differences between ‘poor’ and ‘good’ and ‘marginal’ seats are much more apparent. The occupant is offered little support, the neck and spine over-extend as the head restraint proves insufficient. Little energy is absorbed and the harness fails to restrain the body as the vehicle decelerates, allowing the occupant to move too far forward and upward, potentially causing further injury.