Numerical inverse engineering as a route to determine the dynamic mechanical properties of metallic cellular solids

Metallic cellular solids are recognized for their high strength to weight ratio, being desirable for applications in the transportation industries to reduce fuel consumption and emissions. Although, there have been significant developments in the manufacturing of these materials and in the prediction of their static mechanical properties, their dynamic behavior (e.g. harmonic response and damping ratio) is still difficult to characterize by direct methods. This is due to the usual complex shape and low damping of metallic cellular solids and the inclusion of external damping by the instrumentation in vibration tests. This study presents an indirect method, based on a numerical inverse engineering approach, to determine the true apparent modulus and damping ratio of metallic cellular solids. For validation purposes, the proposed method was applied to Al-based non-stochastic cellular solids manufactured by investment casting with different architectures, being determined that their dynamic apparent modulus (1.4–217.2 MPa) is significantly different from the static structural results. The damping ratios of these samples were also successfully determined (0.002–0.011) and it is shown that these values are within the expected range for this aluminum based cellular solids.