Patent ID: 6839639

Claim:
A method for predicting mechanical behaviour, and/or the effect of mechanical behaviour, of a body B of a system A including the body and subjected to mechanical impact P, the mechanical behaviour including fracture of the body B or of a part of the body B as a result of the impact, the system A being complex in that the body B is built up as a composite body, and the fracture of the body B or the part thereof is complex in that it includes tensile fracture and fracture other than pure tensile fracture, the method comprising (a) providing a model M of the system A, the model M including a physical model, designated B model , of the body B which is geometrically similar to the body B, or of the part thereof which is subjected to fracture, but differs from the body B or the part thereof in that 1. the materials of the model body B model differ from the corresponding materials of the body B or the part thereof by having mechanical properties, including mechanical properties decisive for complex fracture, which are different from the mechanical properties of the body B, and 2. the size of the model body B model optionally differs from the size of the body C, the relationship between the size and the materials of the model body B model and the size and the materials of the body B or the part thereof being such that the ratio between at least two of the size/behaviour-related parameters decisive to complex fracture behaviour is identical or substantially identical in the model body B model and in the body B or the part thereof, the at least two parameters including at least one parameter which is not a parameter solely related to pure tensile fracture, or the said ratio differs from being identical or substantially identical by a known or assessible correction function; (b) subjecting the model system to a mechanical impact P model which is adapted so that it is geometrically and dynamically similar to the mechanical impact P; (c) recording the behaviour of the model body B model resulting from the influence, including the complex fracture behaviour thereof and/or the effect of said complex fracture behaviour; and (d) determining the predicted mechanical behaviour of the body B or the part thereof, including the complex fracture behaviour of the body B or the part thereof, and/or the effect of the complex fracture behaviour, by transferring the recorded behaviour of the model body B model to predicted geometrically similar behaviour of the body B or the part thereof by the use of one or more algorithms which include the above-mentioned at least two parameters and, if necessary, the above-mentioned correction function.