Show/Hide Menu
Hide/Show Apps
Logout
Türkçe
Türkçe
Search
Search
Login
Login
OpenMETU
OpenMETU
About
About
Open Science Policy
Open Science Policy
Open Access Guideline
Open Access Guideline
Postgraduate Thesis Guideline
Postgraduate Thesis Guideline
Communities & Collections
Communities & Collections
Help
Help
Frequently Asked Questions
Frequently Asked Questions
Guides
Guides
Thesis submission
Thesis submission
MS without thesis term project submission
MS without thesis term project submission
Publication submission with DOI
Publication submission with DOI
Publication submission
Publication submission
Supporting Information
Supporting Information
General Information
General Information
Copyright, Embargo and License
Copyright, Embargo and License
Contact us
Contact us
Nonlinear compressible finite viscoleasticity of epoxy-based polymers
Date
2019-01-01
Author
Dal, Hüsnü
Gromala, P. J.
Han, B.
Metadata
Show full item record
This work is licensed under a
Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License
.
Item Usage Stats
219
views
0
downloads
Cite This
Epoxy-based polymers are widely used in the semiconductor industry as thermal and/or electrical interfaces and as encapsulating material. In the automotive industry, epoxy-based molding compounds (EMCs) are often used to protect not only the single IC packages but also the entire electronic control units (ECUs) (or the power modules). The stress caused by the mismatch of the coefficient of thermal expansion (CTE) between EMC and adjacent materials is one of the major causes for premature failure. In the temperature range of interest, the mold material used in the specific applications exhibits a highly nonlinear behavior. Especially around the glass transition temperature, a dominant nonlinear viscous characteristic of the mold material can be observed. During operation of the aforementioned applications, the epoxy-based polymers are subjected to elevated temperatures around the glass transition temperature, where the material exhibits significant volumetric viscosity in addition to shear viscosity. Traditionally, the nonlinear viscoelastic constitutive models do not consider the volumetric viscoelastic behavior examined in epoxy-based polymers at elevated temperatures. In this contribution, we present the theoretical modeling of these materials. On the theoretical side, we propose a new finite viscoelastic constitutive model, which accounts for the nonlinear volumetric and isochoric viscoelasticity observed in this class of materials. To this end, the polymer network is additively decomposed into a strong elastic network and a superimposed secondary network responsible for rate-dependent response. A nonlinear equation is proposed for the evolution of the viscous deformations in the sense of Dal (2011, Ph.D. thesis, TU Dresden). Regarding an accelerated product development process using commercial software packages, accurate and predictive material modeling is vital. The proposed model is proven to be a very powerful tool for accelerating the development process of electronic control units or power modules by better prediction and evaluation of the limits.
URI
https://hdl.handle.net/11511/46972
DOI
https://doi.org/10.1201/9780429324710-59
Collections
Department of Mechanical Engineering, Conference / Seminar
Suggestions
OpenMETU
Core
Nanocrystal silicon based visible light emitting pin diodes
Anutgan, Mustafa; Katırcıoğlu, Bayram; Department of Physics (2010)
The production of low cost, large area display systems requires a light emitting material compatible with the standard silicon (Si) based complementary metal oxide semiconductor (CMOS) technology. The crystalline bulk Si is an indirect band semiconductor with very poor optical properties. On the other hand, hydrogenated amorphous Si (a-Si:H) based wide gap alloys exhibit strong visible photoluminescence (PL) at room temperature, owing to the release of the momentum conservation law. Still, the electrolumine...
Thermal effects of gate connected field-plates and surface passivation on AlGaN/GaN HEMTs
Kara, Doğacan; Okutucu Özyurt, Hanife Tuba; Dönmezer, Nazlı; Department of Mechanical Engineering (2018)
AlGaN/GaN high electron mobility transistors (HEMTs) are widely preferred in automotive, space, and military applications due to their superior electrical and thermal properties. However, when operated in full capacity, their electrical reliability drops significantly due to electron collapse, device degradation, concentrated heating, and mechanical stresses. To increase the reliability and maximum performance of GaN HEMTs, field-plate and surface passivation technologies are used frequently. Although signi...
Performance evaluation and comparison of low voltage grid-tied three-phase AC/DC converter configurations with SI and SIC semiconductor switches
Öztoprak, Oğuzhan; Hava, Ahmet Masum; Department of Electrical and Electronics Engineering (2019)
In this thesis, as compared to silicon IGBT (Si-IGBT) technology, the advantages of using higher efficiency and faster wide bandgap silicon carbide (SiC) semiconductor switches in low voltage three-phase grid-tied PWM DC/AC voltage source converters (VSCs) are investigated in terms of sizing, efficiency and economic considerations for MW-scale photovoltaic power plant applications. As the cost and energy efficiency of a VSC strongly affect the total system economics, this thesis proposes a design methodolog...
Polystyrene / boron nitride nanotube composites: synthesis, processing and characterization
Balık, Erdem; Bayram, Göknur; Sezgi, Naime Aslı; Department of Chemical Engineering (2015)
In recent years, boron nitride nanotubes (BNNTs) have been added to polystyrene (PS) which is a widely used thermoplastic polymer in order to improve its thermal and mechanical properties. Solution mixing and melt blending techniques are commonly used methods to prepare polymer-boron nitride nanotube (BNNT) composites. However, these two composite preparation methods have a common problem about the dispersion of fillers in the polymer matrix. In this study, PS-BNNT composites were prepared using masterbatch...
Colloidal CdSe Quantum Wells with Graded Shell Composition for Low-Threshold Amplified Spontaneous Emission and Highly Efficient Electroluminescence
Keleştemur, Yusuf; Anni, Marco; Yakunin, Sergii; De Giorgi, Maria Luisa; Kovalenko, Maksym V. (2019-12-01)
Semiconductor nanoplatelets (NPLs) have emerged as a very promising class of colloidal nanocrystals for light-emitting devices owing to their quantum-well-like electronic and optical characteristics. However, their lower photoluminescence quantum yield (PLQY) and limited stability have hampered the realization of their outstanding luminescent properties in device applications. Here, to address these deficiencies, we present a two-step synthetic approach that enables the synthesis of core/shell NPLs with pre...
Citation Formats
IEEE
ACM
APA
CHICAGO
MLA
BibTeX
H. Dal, P. J. Gromala, and B. Han, “Nonlinear compressible finite viscoleasticity of epoxy-based polymers,” 2019, Accessed: 00, 2020. [Online]. Available: https://hdl.handle.net/11511/46972.