Master Degree / Yüksek Lisans Tezleri

Permanent URI for this collectionhttps://hdl.handle.net/11147/3008

Browse

Filters

1998 - 199912020 - 20211

Settings

Subject: search.filters.subject.Plastics

Search Results

Now showing 1 - 2 of 2
  • Master Thesis
    On the Selection of Material Model for the 3d Printed Plastics
    (01. Izmir Institute of Technology, 2021) Yorulmazlar, Berika; Taşdemirci, Alper; Taşdemirci, Alper; 03.10. Department of Mechanical Engineering; 03. Faculty of Engineering; 01. Izmir Institute of Technology
    In this study, the behavior of suitable material models which fulfil the need of representation of static and dynamic constitutive behavior ABS plastic produced with Fused Deposition Modeling (FDM) method was investigated. The accuracy of material model strongly depends on the accurate determination of its constants. These constants were obtained by conducting quasi-static and high strain rate experimental studies. The high strain rate tests of FDM built ABS samples were performed using split-Hopkinson pressure bar (SHPB) and split-Hopkinson tension bar (SHTB) and gas gun set-ups. Numerical models were conducted by using the commercial explicit finite element code LS-DYNA 971. Raw data obtained from experiments at low and high strain rates, were reduced and defined in material models. ΜΑΤ_24, ΜΑΤ_81, ΜΑΤ—187 material models were considered in numerical models to investigate the constitutive behavior of the FDM b^ilt ABS material. Good correlation was observed between the numerical and experimental data with the use of selected material models. Then, Generalized Incremental Stress-State dependent damage Model (GISSMO) was selected to characterize the failure behavior of the FDM built ABS. Parameters and curves that defines the state necking and failure occurs at, were found by using optimisation tool, LS-OPT. After observing successful match between the numerical and experimental forcedisplacement curves, GISSMO parameters were defined in SHTB and gas gun numerical models. The results showed good correlation for also the gas gun and SHTB tests in terms of failure behavior, eventually. These imply that GISSMO has the potential to predict necking and localization of deformation of the 3D-printed ABS plastics for different load cases.
  • Master Thesis
    Polymers as Design Materials for Toy Industry
    (Izmir Institute of Technology, 1998) Ünver, Kemal Hakan; Seçkin, Yavuz; Seçkin, Yavuz; 02.04. Department of Industrial Design; 02. Faculty of Architecture; 01. Izmir Institute of Technology
    In this thesis it is intended to investigate the superiority of plastics as a material for a specific product design. Plastics with their intrinsic capabilities, have too many improved characteristics to offer to individuals which makes any research very valuable.When making this research, the methods to be employed were not only limited with library researches but also contained bilateral relations with various producers of either the material or the toys. Under the light of these findings and experiences the formation of the most convenient material was selected for the product. The second point was to design a toy and/or a system for children which would help them get prepared for the coming years. It is found out that, for children toys are more meaningful when combined with their imagination. That is why it is intended to design for preschool children when their imagination is as pure as it can be.Finally it is concluded that with the debut of plastics materials in individuals lives, the characterization of forms, functions and ideas were highly and easily achieved.