Each year, The National Highway Traffic Safety Administration (NHTSA) tests roughly 90 to 150 cars. It evaluates each vehicle is evaluated in four areas—frontal crash test, side barrier crash test, side pole crash test, and rollover resistance test—that simulate common crash scenarios like head-on collisions, being T-boned, and rollovers. Using crash testing technology helps the design of vehicles that provide passengers with a high level of protection if a crash occurs. ISO 7862:2004— Road Vehicles – Sled Test Procedure For The Evaluation Of Restraint Systems By Simulation Of Frontal Collisions provides specifications to conduct a sled test procedure to evaluate restraint systems in road vehicles.
What Is a Sled Test?
A sled test is a simplified crash test that makes it possible for engineers to test various combinations of restraint systems in non-destructive full-crash scenarios. By using a sled (i.e., a rigid guided platform which can be accelerated or decelerated within specified limits and on which the vehicle or its test-relevant structure(s) can be mounted), seating apparatuses are tested in a simulated crash without having to crash a full prototype vehicle. Sled tests analyze primary and secondary restraint systems, automotive seats, and seat belts to determine their safety in front, side, and rear impact collisions. The goal of sled tests is to increase vehicle safety.
The potential of sled tests lies mainly in a laboratory environment, where input conditions are always the same. Adhering to sled test guidelines like those in ISO 7862:2004 are critical to assure consistent and quality testing.
What Is ISO 7862?
ISO 7862:2004 specifies a sled test procedure for the evaluation of restraint systems in road vehicles by simulating frontal collisions. Its helps to improve test methods for evaluating restraint system efficacy and harmonize existing test methods, especially to enable the comparison of results of tests carried out in different laboratories. This standard is applicable to restraint systems used within the structure of a passenger car as defined in ISO 3833. Deviations from its requirements are permitted, provided they have no significant effect on the results of the test.
How to Perform Side Sled Tests
Sled tests are effective in aiding the development for more safety vehicles equipped with side impact safety devices and reducing the cost and period needed to prepare prototype test vehicles. Typically, only a few vehicle components are needed to perform side (lateral) sled tests. As the side sled tests are performed, the catapult accelerates vehicle components and dummies along a rail. The sled acceleration is several times higher than the gravitational acceleration.
In a crash test, the vehicle is usually accelerated to a prescribed speed and then crashed into a fixed item. As a result of the collision, the occupants move by inertia in the direction the vehicle was travelling in prior to the collision. The occupants are then caught by restraint systems, such as airbags or safety belts. Body structure of the impacted vehicle and side impact safety devices, such as a door trim and a side airbag, determine dummy responses in side impact tests. These factors reduce the crash forces applied to the dummy.
ISO 7862:2004— Road Vehicles – Sled Test Procedure For The Evaluation Of Restraint Systems By Simulation Of Frontal Collisions is available on the ANSI Webstore.