In-plane dynamic crushing of honeycomb. Part II: application to impact

• Published in: International journal of mechanical sciences Vol. 44; no. 8; pp. 1697 - 1714
• Main Authors: Hönig, A, Stronge, W.J
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.08.2002; Elsevier
• Subjects: Computational techniques; Computer simulation; Crushing; Deformation; Energy dissipation; Exact sciences and technology; Finite element method; Finite-element and galerkin methods; Fracture mechanics (crack, fatigue, damage...); Fracture mechanics, fatigue and cracks; Fundamental areas of phenomenology (including applications); Mathematical methods in physics; Physics; Solid mechanics; Strain rate; Structural and continuum mechanics; Deformation band; Measurement; Fold; Total energy; Numerical method; Elastic wave; Experimental study; Porous material; Modeling; Finite element method; Inelasticity; Trapping; Honeycomb structure; Localization; Crush; Mechanical shock
• ISSN: 0020-7403; 1879-2162
• DOI: 10.1016/S0020-7403(02)00061-9

Finite element simulations were employed to analyse in-plane dynamic crushing of two different hexagonal honeycombs (slenderness ratios L/ t=38 and 167). The response of the honeycomb with the smaller slenderness ratio was studied for impact speeds up to 40.0 m/s which corresponds to a nominal strain rate for the specimen of 500 s −1 . Total plastically dissipated energy was used to quantify the effects of increasing strain-rate, since other measures showed a strong dependence on details of the finite element model. The simulations revealed a strong increase of total dissipated energy with increasing impact speed for velocities larger than the critical speed for wave trapping, v cr . One reason was a higher percent of cells collapsing in a symmetric crush mode (IV). Another reason for the larger total dissipation at higher crushing speeds was the greater irregularity in the folding pattern that developed. Experimental and calculated global force-time curves were compared for the honeycomb with the larger slenderness ratio at impact speeds 3.0 and 7.2 m/s and a satisfactory agreement was found. At these low impact speeds there was no increase of initial collapse or plateau stresses. A comparison of sequences of deformed mesh plots and high speed photos showed good correlation of the general distribution and modes of crushing.