Browsing by Author "Movahedi, Nima"

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Citation - WoS: 1
Citation - Scopus: 1
Dynamic Compression of Metal Syntactic Foam-Filled Aluminum Tubes
(Springer, 2024) Movahedi, Nima; Fiedler, Thomas; Sarikaya, Mustafa; Tasdemirci, Alper; Murch, Graeme E.; Belova, Irina V.; Guden, Mustafa; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
The current research investigates the compressive properties of metal syntactic foam (MSF)-filled tubes at dynamic loads with an impact velocity of 4 m/s. For this purpose, A356 aluminum alloy syntactic foams were prepared using an infiltration casting technique with an incorporation of expanded perlite (EP) filler particles. The study involves the testing and comparison of both MSF samples and MSF-filled tubes under dynamic loading scenarios. In the case of MSF-filled tubes, aluminum tubes are either fully filled (FFT) or half-filled (HFT) with MSFs. The manufactured foams and foam cores have a similar macroscopic density across all tested samples. Under dynamic loading, the MSF, HFT, and FFT samples exhibit distinct and different deformation mechanisms. In MSFs, dynamic compression is controlled by shearing of the sample, whereas in HFTs and FFTs, dynamic deformation occurs through the folding and buckling of the tubes, accompanied by partial deformation of the MSF cores.
Citation - Scopus: 1
Epoxy Matrix Nano Composites: Modulus, Strength and Ductility Enhancement Through Auxeticity of Α-Cristobalite Filler
(Elsevier, 2023-10) Güden, Mustafa; Ülker, Sevkan; Movahedi, Nima; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
The negative Poisson's ratio (NPR) nano-size ?-Cristobalite particle/epoxy composites were prepared and tensile tested. The elastic modulus and strength of the composites were improved as the particle volume fraction increased from 0 to 0.02. Unlike the conventional particle reinforced composites, the fracture strain increased with the nano ?-Cristobalite addition, an effect which was ascribed to the intrinsic NPR behavior of the filler. © 2023 Elsevier B.V.
Citation - WoS: 36
Citation - Scopus: 37
Impact Loading of Functionally Graded Metal Syntactic Foams
(Elsevier, 2022-04-06) Movahedi, Nima; Fiedler, Thomas; Taşdemirci, Alper; Murch, Graeme E.; Belova, Irina V.; Güden, Mustafa; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
The present study addresses the impact loading of functionally graded metal syntactic foams (FG-MSF). For comparison, samples of the same material were also compression loaded at quasi-static velocities. Samples of A356 aluminium FG-MSF were produced using counter-gravity infiltration casting with combination of equal-sized layers of expanded perlite (EP) and activated carbon (AC) particles. A modified Split Hopkinson Pressure Bar test set-up was used to impact the FG-MSFs from their EP or AC layers at 55 m/s or 175 m/s impact velocities. A high-speed camera captured the deformation of the samples during testing. It was shown that increasing the loading velocity enhanced both the compressive proof strength and energy absorption of the impacted FG-MSF from both layers, confirming a dynamic strengthening effect of the foam. The samples impacted from both layers at 55 and 175 m/s showed a transition and a shock mode of deformation, respectively. The impacted samples at 55 m/s experienced lower final average strain values compared to 175 m/s.