Impact energy absorption in an Al foam at low velocities

Ramachandra, Srinivas Sulugodu

doi:10.1016/s1359-6462(03)00431-7

Cited by 108 publications

(63 citation statements)

References 10 publications

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“…Quasi-static experiment result is also added. For comparison, Paul and Ramachandra's [4,11] compression tests results are plotted. Note that the size of indenter which Ramachandra used is different from this research, their indentation tests results are not presented here.…”

Section: Variation Of Energymentioning

confidence: 99%

“…When this material is frequently used in blast-protected devices [2], indentation becomes a potential mode of failure. Ramachandra et al [3,4] experimentally investigated the indentation behaviour of an aluminium foam under dynamic loads. In their research, drop-tower experiments were used to investigate the energy-absorption ability of aluminium foams under a velocity of 3∼30 m/s.…”

Section: Introductionmentioning

confidence: 99%

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Indentation of aluminium foam at low velocity

Shi

Miao

Liu

et al. 2015

EPJ Web of Conferences

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Abstract. The indentation behaviour of aluminium foams at low velocity (10 m/s ∼ 30 m/s) was investigated both in experiments and numerical simulation in this paper. A flat-ended indenter was used and the force-displacement history was recorded. The Split Hopkinson Pressure bar was used to obtain the indentation velocity and forces in the dynamic experiments. Because of the low strength of the aluminium foam, PMMA bar was used, and the experimental data were corrected using Bacon's method. The energy absorption characteristics varying with impact velocity were then obtained. It was found that the energy absorption ability of aluminium foam gradually increases in the quasi-static regime and shows a significant increase at ∼10 m/s velocity. Numerical simulation was also conducted to investigate this process. A 3D Voronoi model was used and models with different relative densities were investigated as well as those with different failure strain. The indentation energy increases with both the relative density and failure strain. The analysis of the FE model implies that the significant change in energy absorption ability of aluminium foam in indentation at ∼10 m/s velocity may be caused by plastic wave effect.

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Section: Variation Of Energymentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Indentation of aluminium foam at low velocity

Shi

Miao

Liu

et al. 2015

EPJ Web of Conferences

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“…Buna göre darbe enerjisi ve penetrasyon miktarındaki artış ile absorbe edilen enerji miktarı artmıştır. Darbe hızındaki artış ile metalik köpüklerin enerji absorbe kabiliyetlerinin arttığı diğer araştırmacılar tarafından da belirtilmiştir [13,14]. Absorbe olan enerjinin darbe olayında malzeme tarafından emilen tüm enerji olduğu eşit enerji doğrusu üzerinden anlaşılmaktadır.…”

Section: Kuvvet-çökme (F-d) Eğrileri (Force-deflection (F-d) Curves)unclassified

“…Örneğin metalik köpüklerin statik girinti ve penetrasyon özelliklerinin belirlenmesi üzerine yapılan çalışmalarda köpüğün yalnızca delici ucun temas ettiği bölgede plastik deformasyona uğradığı belirtilmiştir [8,12]. Ramachandra ve Li tarafından yapılan çalışmalarda penetrasyon direncinin 10 m/s'den daha büyük hızlarda artığı belirtilmiştir [13,14]. Lua ve arkadaşları darbe hızının absorbe edilen toplam enerji ve bölgesel deformasyon üzerinde etkili olduğunu belirtmiştir [15].…”

Section: Gi̇ri̇ş (Introduction)unclassified

TOZ METALURJİSİ YÖNTEMİYLE ÜRETİLEN AlSi7 KÖPÜKLERİN DÜŞÜK HIZLI DARBE ENERJİLERİ ALTINDA PENETRASYON DAVRANIŞININ İNCELENMESİ

Çinici¹,

Gökmen²,

Uzun³

et al. 2014

Gazi Üniversitesi Mühendislik-Mimarlık Fakültesi Dergisi

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ÖZETBu çalışmada AlSi7 köpüklerin düşük hızlı darbe enerjileri altındaki penetrasyon davranışları incelenmiştir. Bu amaçla toz metalurjisi yöntemi ile üretilen 55x55x20 mm boyutlarında Al köpüklere ağırlık düşürme test cihazı kullanarak farklı hızlarda (1,2 -3 ms -1 ) darbeler uygulanmıştır. Bir numune üzerinde delinme meydana gelene kadar yapılan darbe testleri ile saplanma ve delinme darbe davranışları incelenmiştir. Darbe sonrası numunelerin içyapılarında meydana gelen değişiklikler makro boyutta incelenmiştir.Anahtar kelimeler: Darbe enerjisi, alüminyum köpük, toz metalurjisi INVESTIGATION OF THE PENETRATION BEHAVIOR OF AlSi7 FOAM, PRODUCED BY POWDER METALLURGY METHOD, UNDER LOW-VELOCITY IMPACT ENERGIES ABSTRACTIn this study, the impact behaviors of AlSi7 foams under low-velocity impact energies were investigated. The low-velocity impacts (1,2 -3 ms -1 ) were applied to the samples with 55x55x20 mm dimensions using the weight drop test machine. The impact tests were performed until perforation took place on a sample and so penetration and perforation impact behavior were analyzed. The changes in the internal structures of the samples after the impact were observed in the macro level.

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“…Despite the lack of a general conclusion on the strain-rate sensitivity of aluminium foams, the strainrate hardening of compressive strength of closed-cell aluminium Alporas foam has been widely observed [1][2][3][4][5][6]. Meanwhile, a number of explanations have been proposed.…”

Section: Introductionmentioning

confidence: 99%

Strain-rate sensitivity of foam materials: A numerical study using 3D image-based finite element model

Sun

Withers

2015

EPJ Web of Conferences

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Abstract. Realistic simulations are increasingly demanded to clarify the dynamic behaviour of foam materials, because, on one hand, the significant variability (e.g. 20% scatter band) of foam properties and the lack of reliable dynamic test methods for foams bring particular difficulty to accurately evaluate the strain-rate sensitivity in experiments; while on the other hand numerical models based on idealised cell structures (e.g. Kelvin and Voronoi) may not be sufficiently representative to capture the actual structural effect. To overcome these limitations, the strain-rate sensitivity of the compressive and tensile properties of closed-cell aluminium Alporas foam is investigated in this study by means of meso-scale realistic finite element (FE) simulations. The FE modelling method based on X-ray computed tomography (CT) image is introduced first, as well as its applications to foam materials. Then the compression and tension of Alporas foam at a wide variety of applied nominal strain-rates are simulated using FE model constructed from the actual cell geometry obtained from the CT image. The stain-rate sensitivity of compressive strength (collapse stress) and tensile strength (0.2% offset yield point) are evaluated when considering different cell-wall material properties. The numerical results show that the rate dependence of cell-wall material is the main cause of the strain-rate hardening of the compressive and tensile strengths at low and intermediate strain-rates. When the strain-rate is sufficiently high, shock compression is initiated, which significantly enhances the stress at the loading end and has complicated effect on the stress at the supporting end. The plastic tensile wave effect is evident at high strain-rates, but shock tension cannot develop in Alporas foam due to the softening associated with single fracture process zone occurring in tensile response. In all cases the micro inertia of individual cell walls subjected to localised deformation is found to have negligible effect on the macro strain-rate sensitivity of Alporas foam.

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Impact energy absorption in an Al foam at low velocities

Cited by 108 publications

References 10 publications

Indentation of aluminium foam at low velocity

Indentation of aluminium foam at low velocity

TOZ METALURJİSİ YÖNTEMİYLE ÜRETİLEN AlSi7 KÖPÜKLERİN DÜŞÜK HIZLI DARBE ENERJİLERİ ALTINDA PENETRASYON DAVRANIŞININ İNCELENMESİ

Strain-rate sensitivity of foam materials: A numerical study using 3D image-based finite element model

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