Title: Door Latch Strength in a Car Body Environment
text: Federal Motor Safety Standard (FMVSS) 206 regulates the minimum strength of side door latches in passenger carrying vehicles. The purpose of the standard's requirements is “to reduce the likelihood of occupants being ejected from vehicles in real world accidents.” Investigation of unwanted door openings during accidents has revealed various types of latch failures that do not produce latch and/or striker damage consistent with that found in Federal Motor Vehicle Safety Standard compliance testing. An intersection collision in which a striking vehicle contacts the struck vehicle aft of the affected door has for many years been considered the “most critical to door latch performance” (1). This type of car to car collision will often result in structural separation of the door end panel, “B” post striker panel or latch/striker assembly. These structural failures combine tensile and shear loading on the latch/striker assembly. This paper defines the state of the industry with regard to vehicle door latch strength using a simple testing method that produces door latch separations more consistent with common intersection side impact collisions. The test methodology simultaneously applies both longitudinal and lateral loads as the vector sum of the FMVSS 206 defined loads. To place the test findings in perspective, results are normalized using the existing 206 requirements.