Low velocity failure and integrity assessment of foam core sandwich panels

Mocian, Oana; Constantinescu, Dan Mihai; Sorohan, Ştefan; Sandu, Marin

doi:10.3221/igf-esis.48.24

Cited by 8 publications

(4 citation statements)

References 33 publications

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“…On the other hand, it is noticed that for the impact energy of 4.4 J, EVA_SOFT was the second material that presented the highest restored energy, which means that these foils have a good impact absorption capacity for impacts with high energy levels. These results are in good agreement with those obtained by Mocian et al [24]. Possible mechanical improvements in hard layers or their inserts in mouthguards materials have also been studied.…”

Section: Resultssupporting

confidence: 91%

“…2 and 3, it is possible to conclude that RESIN_IBT is the material with the highest absorbed energy and, consequently, the material with the lowest restored energy (elastic energy). Similar to the study developed by Mocian et al [24], these results indicate that this material has a weak damping capacity. Although no delamination is observed, it is noticed a cohesive fracture of the foil.…”

Section: Resultssupporting

confidence: 90%

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Impact response of different materials for sports mouthguards

Moreira

Ramos

Messias

et al. 2021

Frattura Ed Integrità Strutturale

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Up to this moment, there is no guideline regarding the materials to produce mouthguards. The most used is Ethylene-Vinyl Acetate (EVA). Studies indicate that laminating EVA sheets with rigid components could increase the protection capacities of the mouthguards whereas other studies suggest that only replacement of the material within it structure can increase energy absorption. The aim of this work is to evaluate the impact response of four different foils when compared to a 4 mm thickness EVA sheet. Five groups of different materials were subjected to impact tests with energies of 1.72 J, 2.85 J and 4.40 J. In this context was considered the following materials: EVA foils (G1), EVA foils with an EVA foam core (G2), EVA foils with an acetate core (G3), Foils of Erkoloc-pro (G4) and Foils of Ortho IBT resin (G5). Comparisons between the materials were made by qualitative analysis of the average energy-time and load-displacement curves, as well as by comparison of the peak load, maximum displacement, contact time and absorbed energy using the Kruskal-Wallis test. It was possible to conclude that statistically significant differences were found in the energy absorbed (p=0.001). Laminated foils with a soft core (G2) are a good option to produce mouthguards, while EVA foils with an acetate core (G3) and foils of Ortho IBT resin (G5) were declared unsuitable.

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Section: Resultssupporting

confidence: 91%

Section: Resultssupporting

confidence: 90%

Impact response of different materials for sports mouthguards

Moreira

Ramos

Messias

et al. 2021

Frattura Ed Integrità Strutturale

View full text Add to dashboard Cite

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“…In addition, Mocian et al. 26 considered the influence of different impact velocities over energy absorption and occurred damage. Different face sheets and foam cores have been studied extensively.…”

Section: Introductionmentioning

confidence: 99%

Experimental and numerical investigation of low velocity impact on hybrid short-fiber reinforced foam core sandwich panel

Sharei

Safarabadi

Mashhadi

et al. 2021

Journal of Composite Materials

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This paper presents an experimental and numerical study of the low-velocity impact on foam core sandwich panels reinforced using hybrid short fibers. The foam cores were reinforced with carbon, aramid and carbon-aramid hybrid short fibers. The face-sheets were made of two layers of glass/epoxy, and foam cores were made of two-part polyurethane. In order to acquire the appropriate weight ratio between foam and short fibers, the weight percentage of 10% was chosen for short fibers. Comparing the experimental results proved that carbon, aramid, and carbon-aramid respectively had a better effect on increasing Young modulus by around 100 to 180 per cent. Before performing impact tests, indentation tests were conducted and based on the results for the parameter of impact energy, the value of 6 J was chosen. According to the results of impact tests and the maximum contact force, hybrid reinforced foam, aramid short fiber reinforced foam and carbon short fiber reinforced foam improved the properties respectively by 18 to 30 per cent in comparison to non-reinforced foam. Furthermore, numerical simulations were conducted via ABAQUS. After modeling face-sheet and foam separately, and verifying the results with experiments, the sandwich panel was modeled entirely while the simulation difference of 9.1% on average with the experiment results was concluded.

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“…Besides, after an impact, there is a drastic reduction in the strength due to delamination and core damage. 12 There have been many studies on the strengthening or replacing of the face sheet or core material: for instance, Oana et al 2,13,14 studied the impact behavior and damage features of polymer core composite face sheets, while Demircio glu 15,16 and John 17 studied the changes in the core materials for different values of impact energy on a wood-based sandwich panel. Similarly, Wu et al 18 evaluated the impact performance by applying various face sheets to the polymeric foam core sandwich panels.…”

Section: Introductionmentioning

confidence: 99%

Impact behavior of hollow glass bubble reinforced foam core LNG insulation panel in cryogenic temperature

Lee

Bae

Hwang

et al. 2020

Journal of Composite Materials

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Composite sandwich panels are applied to numerous structures owing to their excellent mechanical properties and thermal performance. In marine craft, sandwich panels are located on the inner walls as an insulation system for the liquefied natural gas (LNG) cargo containment systems (CCSs). Polyurethane foam (PUF), as an insulation material, is commonly used as the core material against a cryogenic temperature of –163°C for the LNG CCSs. Owing to its excellent thermal performance that prevents heat flow from the outside, and because LNG is transported at cryogenic temperatures, PUF is the preferred choice as a core material. However, the LNG CCS is subjected to fluid impact load due to sloshing during a laden voyage, and therefore, the core material needs to be reinforced. In this study, a reinforcement material made of hollow glass bubbles (HGBs) was added to PUF to help withstand the sloshing loads, and the performance of the specimens was investigated in terms of their impact strength and absorption energy. The mechanical impact strength of the final products was investigated through an impact test at cryogenic temperatures and the absorption energy was analyzed along with the dynamic compressive behavior of the sandwich panels.

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Low velocity failure and integrity assessment of foam core sandwich panels

Cited by 8 publications

References 33 publications

Impact response of different materials for sports mouthguards

Impact response of different materials for sports mouthguards

Experimental and numerical investigation of low velocity impact on hybrid short-fiber reinforced foam core sandwich panel

Impact behavior of hollow glass bubble reinforced foam core LNG insulation panel in cryogenic temperature

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