During the Insurance Institute for High Safety’s automobile safety
testing, the Vehicle Research Center is home to a variety of types of
crash tests. Not all of these tests require entire vehicles behind crashed, though.
Automobile crashes can be simulated in the sled lab. This lab makes use
of a sled running on fixed rails that allows for testing of head restraints
or gear within a vehicle, such as booster seats. The IIHS workers attach
components to the sled and
crash dummies are often used in those components. The sled is a steel flatbed that runs
on rails that can be programmed to do specific accelerations and decelerations.
The sled mimics an actual vehicle so that the dummy shows what would happen
to an actual occupant in a real-world wreck. These sled lab tests are
much easier and less expensive to set up than full-scale automobile tests.
One of the regular evaluations of vehicles performed at the Vehicle Research
Center is an evaluation of whether or not the vehicle’s seats are
able to provide protection against whiplash injuries. This evaluation
is based on simulating a rear crash. The vehicle seats are taken out of
the vehicle and mounted to the sled, which is then moved as if it were
a car that had been struck in a rear crash. The test simulates the kind
of crash that might consist of a vehicle being struck from behind by a
vehicle weighing about the same at 20 MPH. The measurements from the dummy
are then used to judge which seats are doing a better job of moving the
head together with the rest of the body in a way that reduces the stresses
and strains in the neck.
Booster seat evaluations are often performed using the sled as well.
Another test performed at the VRC that doesn’t include a full vehicle
crash is for rollovers. It is very important to have a strong roof in
a rollover rash because it keeps the survival space, or occupant compartment,
intact. The vehicle should absorb the forces and energy of the crash without
deforming the occupant space so that there’s room inside for the
restraints work properly. Roof strength is also important because of the
risks associated with ejection during a rollover. If the car’s roof
stays in place, then the windshield and side windows are more likely to
stay in place as well, therefore keeping occupants inside the vehicle.
The IIHS uses a roof crush machine, which measures the strength of the
roof of the vehicle. This machine uses hydraulic cylinders to push a steel
plate into one corner of the roof at a constant speed. The maximum force
that it takes to crush the car is recorded and then divided by the vehicle’s
weight to come up with the strength-to-weight ratio. In the IIHS system
of ratings, a vehicle must be able to achieve a ratio of four or greater
in order to receive a “good”. This test has made a huge difference
in the roof strength of vehicles on the road.
These types of tests performed at the IIHS’s Vehicle Research Center,
as well as vehicle crash tests, work towards making motor vehicles safer
for everyone on the road.