Vehicle Door Latch Safety Measures Based on System Dynamics

The governments of many countries have established regulations that address the issue of vehicle door safety during crash events. Depending on the regulation or specification, analytical tools may be acceptable for verifying the crashworthiness of a latching system. In those instances where actual test crashes are required for verification, analytical methods can still be used to help predict the outcome of a crash test. Two relevant analytical approaches for multibody dynamics computation are discussed in the paper. One is related to monitoring the effects of constant 30G inertia loading in all directions (spherical analysis) and another addresses inertia pulse loading of specified G levels in certain directions. In some crash situations, the latch system compliance with the regulations may be insufficient to prevent door release. To secure the door in the latched position additional safety devices can be deployed in various locations of the door latch system. One group of such devices relies on using inertia catch levers triggered by specific acceleration of vehicle door. The development and tuning of the inertia catch devices is done by analytical means followed by latch system validation during crash tests.