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The effect of the interface between the carbon nanofibers (CNF) or carbon nanotubes (CNT) and the matrix on the properties of a nanocomposite is significant. Therefore, it is important to develop a model that accounts for the effect of the interface on the overall elastic modulus of a nanocomposite. A methodology for predicting the modulus of a nanocomposite is developed in this paper. This methodology uses a conceptual model called inclusion that consists of the nanofiber/nanotube inserted in a hollow cylinder representing the interface. The inclusion is embedded into the matrix. The flexibility of the hollow cylinder represents the effect of the interface. Inputs to this model are the moduli of the CNT/CNF, the matrix and the material representing the interface, as well as the volume fractions of these materials. These properties can be estimated from experiments or from molecular dynamics models.

An experimental method for nondestructive estimation of damage in joints due to high mileage degradation in cars is presented. The method estimates damage by comparing transfer functions of the same car at zero and at high mileage. The potential of the method is demonstrated analytically using a three dimensional concept Finite Element Model (FEM) of a car body to simulate the transfer functions of this car body at zero and at high mileage. The results demonstrate that the method is effective for identifying the damaged joints as well as the relative degree of degradation.

A methodology is presented for developing two tools for design guidance of joints in car bodies. The first tool rapidly predicts the performance characteristics of a given joint. The second finds a joint design that meets given performance targets and satisfies packaging and manufacturing constraints. These tools translate the design parameters defining the geometry of a joint into performance characteristics of that joint and vice-versa. The methodology is demonstrated on a joint of an actual car.