Evaluation and Research of Structural Interaction between of two cars in Car to Car Compatibility

Incompatibility between two colliding cars is becoming an important issue in passive safety engineering. Among various phenomena, indicating signs of incompatibility, over-riding and under-riding are likely caused by geometrical incompatibility in vertical direction. The issue of over-riding and under-riding is, therefore, not only a problem for partner-protection but also a possible disadvantage in self-protection. One of the possible solutions of this dual contradictory problem is to have a good structural interaction between the front-ends of two cars. Studies have been done to develop a test protocol for assessment of this interaction and to define criteria for evaluation but mostly in terms of aggressivity, which is a term describing incompatibility of a relatively stronger car. In this study, it was hypothesized that homogeneous front-end could be a possible better solution for good structural interaction. A homogeneous front-end will result in less aggressivity and better self-protection at the same time, regardless of the front-end stiffness of an opponent car. Stress distribution at the front-end surface can be taken as possible indicators to quantitatively evaluate homogeneity of the car front-end. A multiple load-cell barrier enables to analyze stress distribution by measuring force inputs at discrete load-cells outputs though a crash test. In addition to digitizing stress distribution on the load-cell surface, statistical techniques can be used to quantify the deviation. A simulation study was conducted on simple frame models to examine the validity of the hypothesis and the capability of the proposed indicators.