Development of a novel surface damping treatment

Download

index.pdf

Date

2016

Author

Eyyüpoğlu, Kemal Okan

Metadata

Show full item record

Item Usage Stats

209
views

100
downloads

Constrained layer surface damping treatments techniques have been widely used in commercial and defense products to increase the damping performance. It is known that the performance of surface damping treatments highly depend on the strain energy in the viscoelastic layer. As the strain energy in the viscoelastic layer increases, the energy dissipation magnifies which results in higher damping performance. A good way to magnify strain energy in viscoelastic layer is to increase the distance between the viscoelastic layer and the neutral axis of the base beam. This can be achieved by using stand-off layer which is a layer between the viscoelastic layer and the base beam. The stand-off layer should have very low bending stiffness in order not to prevent the deformation of the beam in lateral direction. Also stand-off layer should have very high shear stiffness in order to allow the viscoelastic layer to take all the shear strain energy on itself. The requirement of having a low bending stiffness and high shear stiffness in addition to minimizing the mass of the damping treatment while targeting a certain damping performance may be translated into a shape optimization problem for the design of the stand-off layer. In this dissertation, a parametric finite element model of the stand-off constrained damping treatment is developed by using a commercial product (ANSYS) and the geometry of the stand-off layer are optimized by using another commercial product (MATLAB). For the determination of the optimum shape of the stand-off layer, topology optimization approach is used along with genetic optimization technique. In the optimization studies conducted in the thesis, the optimum stand-off layer geometry with minimum weight that does not compromise damping performance is seeked.

Subject Keywords

Damping (Mechanics)., Viscoelastic materials., Finite element method., Mathematical optimization.

URI

http://etd.lib.metu.edu.tr/upload/12619822/index.pdf
https://hdl.handle.net/11511/25497

Collections

Graduate School of Natural and Applied Sciences, Thesis

Suggestions

OpenMETU
Core

Development of high-performance anode supported solid oxide fuel cell Timurkutluk, Bora; Timurkutluk, Cigdem; MAT, MAHMUT DURSUN; Kaplan, Yuksel (2012-12-01) A high performance five-layered anode supported solid oxide fuel cell (SOFC) is developed by low-cost tape casting, co-sintering, and screen printing techniques. The cell is composed of NiO/scandium stabilized zirconia (ScSZ) anode support, NiO/ScSZ anode functional layer (AFL), ScSZ electrolyte, lanthanum strontium ferrite (LSF)/ScSZ cathode functional layer, and LSF cathode current collecting layer. The effects of fabrication parameters on the cell performance are investigated and optimized, including co-...
Development of strain monitoring system for glass fiber reinforced composites via embedded electrically conductive pathways Tanabi, Hamed; Erdal Erdoğmuş, Merve (Informa UK Limited, 2019-06-15) Among numerous types of health-monitoring and damage-sensing sensors that can be integrated into composites, electrically conductive sensors offer a simple, cost-effective, and durable option for structural health monitoring in fiber reinforced composites. In this study, a novel approach is introduced to create electrical conductive networks in glass fiber reinforced composites. For this purpose, hollow micro-channels are generated using vaporization of sacrificial components (VaSCs) which are subsequently ...
Development of electrochemical etch-stop techniques for integrated MEMS sensors Yaşınok, Gözde Ceren; Akın, Tayfun; Department of Electrical and Electronics Engineering (2006) This thesis presents the development of electrochemical etch-stop techniques (ECES) to achieve high precision 3-dimensional integrated MEMS sensors with wet anisotropic etching by applying proper voltages to various regions in silicon. The anisotropic etchant is selected as tetra methyl ammonium hydroxide, TMAH, considering its high silicon etch rate, selectivity towards SiO2, and CMOS compatibility, especially during front-side etching of the chip/wafer. A number of parameters affecting the etching are inv...
Fabrication of low reflective nanopore-type black Si layer using one-step Ni-assisted chemical etching for Si solar cell application Takaloo, AshkanVakilipour; Kolahdouz, Mohammadreza; POURSAFAR, Jafar; ES, FIRAT; Turan, Raşit; Ki-Joo, Seung (IOP Publishing, 2018-03-01) Nanotextured Si fabricated through metal-assisted chemical etching (MACE) technique exhibits a promising potential for producing antireflective layer for photovoltaic (PV) application. In this study, a novel single-step nickel (Ni) assisted etching technique was applied to produce an antireflective, nonporous Si (black Si) in an aqueous solution containing hydrofluoric acid (HF), hydrogen peroxide (H2O2) and NiSO4 at 40 degrees C. Field emission scanning electron microscope was used to characterize differen...
Application of Multivariate Adaptive Regression Splines to Sheet Metal Bending Process for Springback Compensation Dilan, Rasim Askin; Balkan, Raif Tuna; Platin, Bülent Emre (EDP Sciences; 2016-07-07) An intelligent regression technique is applied for sheet metal bending processes to improve bending performance. This study is a part of another extensive study, automated sheet bending assistance for press brakes. Data related to material properties of sheet metal is collected in an online manner and fed to an intelligent system for determining the most accurate punch displacement without any offline iteration or calibration. The overall system aims to reduce the production time while increasing the perfor...

Citation Formats

K. O. Eyyüpoğlu, “Development of a novel surface damping treatment,” M.S. - Master of Science, Middle East Technical University, 2016.