Vehicle Crush Prediction Using Finite-Element Techniques 730157
The principal objective of this investigation has been to develop analytical tools in the form of computer programs which will permit the automobile designer to predict the crush characteristics of a given car structure due to forces generated in a variety of impact modes.
The predictive or control capability is embodied in two large computer programs. “TELSAP” forms, reduces, and inverts the vehicle structure mass matrix expressed relative to a datum coordinate system and writes the mass matrix and its inversion onto a file for reading by the “CRUSH” program. “CRUSH” is a general matrix structural analysis program which calculates the large, plastic, rate-sensitive response of an interconnected beam structure due to known dynamic boundary displacement inputs. The theoretical bases and assumptions employed in developing these programs are described along with detailed discussion of how the automobile design engineer might use them to develop a new vehicle structure.
Experimental correlation with the computer models is given for a vehicle-to-vehicle 90 deg intersection collision between a special rigid moving barrier and an intermediate size four-door sedan. The structural model was further correlated with a laboratory test of a clamped-clamped beam struck at its center by an impact pendulum. The correlation indicates general agreement between experimental and analytical results.
By using the computer programs developed in this investigation, the automobile designer is able to reduce the amount of testing required to prove out his design, and is able to identify the benefits of a particular structural reinforcement with a minimum of development time and expense.
