In-plane impact behavior of honeycomb structures randomly filled with rigid inclusions

• Published in: International journal of impact engineering Vol. 36; no. 1; pp. 73 - 80
• Main Authors: Nakamoto, Hiroaki, Adachi, Tadaharu, Araki, Wakako
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 2009; Elsevier
• Subjects: Exact sciences and technology; Finite element method; Fracture mechanics (crack, fatigue, damage...); Fundamental areas of phenomenology (including applications); Honeycomb structure; In-plane impact behavior; Inclusions; Inelasticity (thermoplasticity, viscoplasticity...); Physics; Solid mechanics; Static elasticity (thermoelasticity...); Structural and continuum mechanics; Finite element method; In-plane impact behavior; Honeycomb structure; Inclusions; Deformation band; Mean field approximation; Densification; Volume fraction; Solid inclusion; Strain energy; Bumpers; Inversion; Acoustic absorption; Modeling; Parabolic equation; Elastoplasticity; Energy dissipation; Localization; Energy absorption; Shear band; Mechanical shock
• ISSN: 0734-743X; 1879-3509
• DOI: 10.1016/j.ijimpeng.2008.04.004

The in-plane impact behavior of honeycomb structures randomly filled with rigid inclusions was studied by using the finite element method to clarify the effect of inclusions on the deformation process, mean stress, densification strain, and absorbed energy. The deformation processes of the models were disturbed by inclusions; shear bands were pinned, and the cell regions surrounded by inclusions were shielded. Mean stress, densification strain, and absorbed energy per unit volume normalized by the values of the model without inclusions were found to be only dependent on the fraction of inclusions. As the volume fraction of inclusions increased, the normalized mean stress linearly increased and the normalized densification strain linearly decreased. The normalized absorbed energy per unit volume could be approximated by an inverted parabolic equation. The energy absorption of models with inclusions having volume fractions from 0 to 0.25 was larger than that of the models without inclusions. In particular, honeycomb models with fractions of inclusion from 0.1 to 0.2 exhibited the maximum absorbed energy. The model with a volume fraction larger than 0.4 could not be compressed because the inclusions in the model had already percolated before deformation. The in-plane impact behavior of honeycomb structures as energy absorbing materials can be designed by using the approximate equation and selecting the volume fraction of inclusions.