Honeycomb aluminum structures are used in energy-absorbing constructions in military, automotive, aerospace and space industries. Especially, the protection against explosives in military vehicles is very important. The paper deals with the study of selected aluminum honeycomb sandwich materials subjected to static and dynamic compressive loading. The used equipment includes: static strength machine, drop hammer and Split Hopkinson Pressure Bar (SHPB). The results show the influence of applied strain rate on the strength properties, especially Plateau stress, of the tested material. In each of the discussed cases, an increase in the value of plateau stresses in the entire strain range was noted with an increase in the strain rate, with an average of 10 to 19%. This increase is mostly visible in the final phase of structure destruction, and considering the geometrical parameters of the samples, the plateau stress increase was about 0.3 MPa between samples with the smallest and largest cell size for the SHPB test and about 0.15 MPa for the drop hammer test.
1 September 2018 in Advances in Science and Technology Research Journal
Aim of presented study was to compare plateau stress in honeycomb structures under out-of-plane load calculated using Wierzbicki formula with numerical simulations validated using expe-rimental trials. ALUBOND® Alucore honeycomb structure was examined. The results of theoreti-cal, experimental...
Aluminum honeycomb structures are used in the construction of protective materials due to the positive relationship between their mass and their energy-absorbing properties. Applying such materials in the construction of large machinery, such as military vehicles, requires the development of a new method of finite element modeling, one that considers conditions with high strain rates, because a material model is currently lacking in the available simulation software, including LS-DYNA. In the present study, we proposed and verified a method of numerically modeling honeycomb materials using a simplified Y element. Results with a good level of agreement between the full core model and the Y element were achieved. The obtained description of the material properties was used in the subsequent creation of a homogeneous model. In addition, we considered the influence of increases in pressure and the leakage of the air entrapped in the honeycomb cells. As a result, we were able to attain a high level of accuracy regarding the stress values across the entire range of progressive failure, from the loss of stability to full core densification, and across a wide range of strain rates.