It is well known that a CAB (Curtain Airbag) is one of the most effective restraint systems for protecting the occupant head from a side impact crash or preventing the occupant from ejection during a rollover accident. One of the most fundamental requirements for a CAB is to ensure a robust deployment. Specifically, a CAB should be deployed and positioned well in time without being trapped by any interior parts. Up to now, the deployment performance has been evaluated by measuring the fully-deployed time, which has limitation in that it is difficult to clearly discriminate performance differences resulting from design parameter changes.

The main purpose of this study is to develop a new methodology for evaluating the CAB deployment performance quantitatively and defining corresponding metrics representative of the deployment performance. For this, two test methods focusing on either the local or the global characteristics were developed in the present investigation. The first was designed to directly measure the deployment force exerted on the specific area by measuring the tension force acting on a webbing material using the load cell. The second was devised to show the overall profile of the deployment force and to measure the time history of total force by calculating the sum of inertial and elastic forces applied to a series of spring-bar impact systems. Afterward, several tests were carried out by each method in order to evaluate their repeatability and reproducibility. In addition, the tests were performed for several different CAB designs to evaluate discrimination capability of each test method. From this study, it was found out that the proposed test methods and corresponding metrics can be effectively used for evaluating the deployment performance of CAB’s. It is also expected that the methodology can be applied to optimize design parameters of CAB’s for the robust deployment performance.