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The effect of epoxy-based structural foam on strength, stiffness, and energy absorption of foam filled structural components is investigated and implemented to formulate design guide-lines that can be used in enhancing weight reduction and engineering functions of systems. An experimental approach is first utilized to identify design variables such as foam density, gage, and foam layer thickness, that are needed to enhance the weight/ performance ratio of structural hat-section components. A CAE approach using non-linear, large deformation finite element analysis is used to model the hat-section components. An acceptance level of confidence in the CAE analytical tools is then established based on comparisons of results between the two approaches. Upon that, the CAE analytical tools are deployed in a sensitivity study to quantify the crush/crash characteristics of foam-filled hat-section components with respect to the changes in the afore mentioned design variables.

Model characteristics of a finite element deformable featureless headform with one to four layers of solid elements for the headform skin are studied using both the LS-DYNA3D and FCRASH codes. The models use a viscoelastic material law whose constitutive parameters are established through comparisons of drop test simulations at various impact velocities with the test data. Results indicate that the one-layer model has a significant distinct characteristic from the other (2-to-4-layer) models, thus requiring different parametric values. Similar observation is also noticed in simulating drop tests with one and two layers of solid elements for the headform skin using PAM-CRASH. When using the same parametric values for the viscoelastic material, both the LS-DYNA3D and FCRASH simulations yield the same results under identical impact conditions and, thereby, exhibit a “functional equivalency” between these two codes.

The effect of polyurethane structural foam on strength, stiffness, and energy absorption of foam filled structural components is investigated to formulate design directions that may be used in weight reduction and engineering functions of vehicle systems. An experimental/testing approach is first utilized using Taguchi’s DOE to identify design variables [foam density, gage, and material type], that are needed to determine the weight/performance ratio of structural hat-section components. An analytical CAE approach is then used to analyze the hat-section components using non-linear, large deformation finite element analysis. An accepted level of confidence in the CAE analytical tools is then established based on comparison of results between the two approaches.