A Multilayer Membrane-Tension Automotive Door-Barrier System 900717
An alternative device based on the membrane-tension principle was developed to improve the resistance of vehicle doors to side impact. The device is comprised of several layers of sheets. The outermost layer is essentially flat and the other layers are corrugated, each with the same pitch but with a successively greater depth. The ends of each layer are attached to tabs which are connected to the door frame in a manner suitable for developing the required forces. In this concept, the side impact pushes inward on the outer sheet and causes it to develop membrane tension because its axial movement is restrained at its ends. As the inward intrusion increases, the outer sheet stretches inelastically and eventually ruptures. This action continues as successive sheet layers are stretched to rupture. The computer program, DOOR1, was developed to aid in designing the device to suit various geometries and packaging criteria. Tests were conducted on prototype specimens and compared to a companion test of an existing system. The tests indicated that the new door barrier device acting alone can deform up to 18 inches and reach a maximum load of at least 11,000 pounds in a typical three-layer, 46-1/2-inch span configuration. Details can be selected so that the load-deformation curve can be engineered to provide a desired shape. Because it appears that the new device could potentially improve crash resistance, full-scale tests on a vehicle are planned.