Effects of impactor shape on the deformation and energy absorption of closed cell aluminium foams under low velocity impact

Flexural strength and low velocity impact properties were investigated in terms of possibile improvements due to epoxy matrix modification by SiO2 nanoparticles (1%, 2%, 3%, 5%, 7%wt.) in glass/epoxy laminates formed using hand lay-up method. The matrix resin was Hexion L285 (DGEBA) with Nanopox A410 - SiO2 (20 nm) nanoparticle suspension in the base epoxy resin (DGEBA) supplied by Evonic. Modification of epoxy matrix by variable concentrations of nanoSiO2 does not offer significant improvements in the flexural strength σg, Young’s modulus E and interlaminar shear strength for 1% 3% and 5% nanoSiO2 and for 7% a slight drop (up to ca. 15-20%) was found. Low energy (1J) impact resistance of nanocomposites represented by peak load in dynamic impact characteristics was not changed for nanocompoosites compared to the unmodified material. However at higher impact energy (3J) nanoparticles appear to slightly improve the impact energy absorption for 3% and 5%. The absence or minor improvements in the mechanical behaviour of nanocomposites is due to the failure mechanisms associated with hand layup fabrication technique: (i.e. rapid crack propagation across the extensive resin pockets and numerous pores and voids) which dominate the nanoparticle-dependent crack energy absorption mechanisms (microvoids formation and deformation).

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Low Velocity Impact Behavior of Closed-Cell Aluminum Foam Considering Effect of Foam Skin

Lecture Notes in Mechanical Engineering - Advances in Materials and Manufacturing Engineering ◽

10.1007/978-981-15-1307-7_16 ◽

2020 ◽

pp. 143-149

Author(s):

Y. M. Chordiya ◽

M. D. Goel

Keyword(s):

Aluminum Foam ◽

Low Velocity Impact ◽

Impact Behavior ◽

Low Velocity ◽

Velocity Impact ◽

Closed Cell

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Redesign of Crash-Box for Enhanced Energy Absorption in Low Velocity Impact

10.4271/2016-28-0254 ◽

2016 ◽

Cited By ~ 1

Author(s):

Nitin Tekavde ◽

Srikari Srinivas ◽

Vinod Banthia ◽

Suman Mittemari

Keyword(s):

Energy Absorption ◽

Low Velocity Impact ◽

Low Velocity ◽

Velocity Impact

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Low-velocity impact response of wood-strand sandwich panels and their components

Holzforschung ◽

10.1515/hf-2017-0169 ◽

2018 ◽

Vol 72 (8) ◽

pp. 681-689 ◽

Cited By ~ 5

Author(s):

Mostafa Mohammadabadi ◽

Vikram Yadama ◽

LiHong Yao ◽

Debes Bhattacharyya

Keyword(s):

Energy Absorption ◽

Impact Energy ◽

Failure Modes ◽

Sandwich Panels ◽

Low Velocity Impact ◽

Insulation Material ◽

Low Velocity ◽

Velocity Impact ◽

Section Modulus ◽

The Impact

AbstractProfiled hollow core sandwich panels (SPs) and their components (outer layers and core) were manufactured with ponderosa and lodgepole pine wood strands to determine the effects of low-velocity impact forces and to observe their energy absorption (EA) capacities and failure modes. An instrumented drop weight impact system was applied and the tests were performed by releasing the impact head from 500 mm for all the specimens while the impactors (IMPs) were equipped with hemispherical and flat head cylindrical heads. SPs with cavities filled with a rigid foam insulation material (SPfoam) were also tested to understand the change in EA behavior and failure mode. Failure modes induced by both IMPs to SPs were found to be splitting, perforating, penetrating, core crushing and debonding between the core and the outer layers. SPfoams absorbed 26% more energy than unfilled SPs. SPfoams with urethane foam suffer less severe failure modes than SPs. SPs in a ridge-loading configuration absorbed more impact energy than those in a valley-loading configuration, especially when impacted by a hemispherical IMP. Based on the results, it is evident that sandwich structure is more efficient than a solid panel concerning impact energy absorption, primarily due to a larger elastic section modulus of the core’s corrugated geometry.

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