Experimental and Numerical Simulation Study of Pre-deformed Heavy Copper Wire Wedge Bonds

2014 ◽  
Vol 2014 (1) ◽  
pp. 000289-000294 ◽  
Author(s):  
Andreas Unger ◽  
Walter Sextro ◽  
Simon Althoff ◽  
Paul Eichwald ◽  
Tobias Meyer ◽  
...  
Keyword(s):  
Numerical Study ◽  
Copper Wire ◽  
Cold Work ◽  
Optimization Technique ◽  
The Finite Element Method ◽  
Model Quality ◽  
Local Material ◽  
Deformation Phase ◽  
Ultrasonic Wire Bonding ◽  
Nominal Contact Area

To implement a self-optimization technique for ultrasonic wire bonding machines, a model of the pre-deformation phase is essential. The local material characteristics change abruptly because of the cold work during deformation. Investigations confirm a significant influence on the material properties of the contact members during touchdown. In a first step this paper validates the importance of modeling the pre-deformation experimentally. In a second step, the paper presents a numerical study of the elasto-plastic deformation based on the finite element method. This model includes measured overshoots in the touchdown forces in order to achieve accurate model responses. A validation of the model with the resulting nominal contact area, surface pressure and penetration depth reveals the high model quality.

Welding Characteristics of Thin Copper Wire Using Complex Vibration Ultrasonic Wire Bonding Systems

1990 ◽  
Vol 29 (S1) ◽  
pp. 173 ◽  
Author(s):  
Jiromaru Tsujino ◽  
Yoshihiro Murayama ◽  
Hiroshi Furuya
Keyword(s):  
Copper Wire ◽  
Wire Bonding ◽  
Bonding Systems ◽  
Ultrasonic Wire Bonding

Numerical Study of the Flow Forming Process of AISI 630 Stainless Steel

2011 ◽  
Vol 264-265 ◽  
pp. 24-29 ◽  
Author(s):  
Seyed Mohammad Ebrahimi ◽  
Seyed Ali Asghar Akbari Mousavi ◽  
Mostafa Soltan Bayazidi ◽  
Mohammad Mastoori
Keyword(s):  
Feeding Rate ◽  
Surface Defects ◽  
Numerical Study ◽  
Internal Diameter ◽  
The Finite Element Method ◽  
Forming Process ◽  
Flow Forming ◽  
Cold Forming ◽  
External Variables ◽  
Experimental Process

Flow forming is one of the cold forming process which is used for hollow symmetrical shapes. In this paper, the forward flow forming process is simulated using the finite element method and its results are compared with the experimental process. The variation of thickness of the sample is examined by the ultrasonic tests for the five locations of the tubes. To simulate the process, the ABAQUS explicit is used. The effects of flow forming variables such as the angle of rollers and rate of feeding of rollers, on the external variables such as internal diameter, thickness of tube and roller forces are considered. The study showed that the roller force and surface defects were reduced with low feeding rate and low rollers attack angles. Moreover, the sample internal diameter increased at low feeding rate and low rollers attack angles. The optimum variables for flow forming process were also obtained.

scholarly journals Modeling of Size Effects in Bending of Perforated Cosserat Plates

2017 ◽  
Vol 2017 ◽  
pp. 1-19 ◽  
Author(s):  
Roman Kvasov ◽  
Lev Steinberg
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Numerical Study ◽  
The Finite Element Method ◽  
Classical Elasticity ◽  
Element Analysis ◽  
Plate Deformation ◽  
The Finite Element Analysis ◽  
Circular Holes ◽  
Different Shapes

This paper presents the numerical study of Cosserat elastic plate deformation based on the parametric theory of Cosserat plates, recently developed by the authors. The numerical results are obtained using the Finite Element Method used to solve the parametric system of 9 kinematic equations. We discuss the existence and uniqueness of the weak solution and the convergence of the proposed FEM. The Finite Element analysis of clamped Cosserat plates of different shapes under different loads is provided. We present the numerical validation of the proposed FEM by estimating the order of convergence, when comparing the main kinematic variables with an analytical solution. We also consider the numerical analysis of plates with circular holes. We show that the stress concentration factor around the hole is less than the classical value, and smaller holes exhibit less stress concentration as would be expected on the basis of the classical elasticity.

Theoretical Study on Recombination Efficiency at S-DPVBi/Alq3 Interface in OLED

2012 ◽  
Vol 629 ◽  
pp. 44-48
Author(s):  
Young Wook Hwang ◽  
Kwang Sik Kim ◽  
Tae Young Won
Keyword(s):  
Indium Tin Oxide ◽  
Numerical Study ◽  
Organic Light Emitting Diodes ◽  
Transport Layer ◽  
Electron Transport Layer ◽  
The Finite Element Method ◽  
Light Emitting ◽  
Recombination Efficiency ◽  
Interface Barrier ◽  
Recombination Kinetics

In this paper, we report our numerical study on the electrical-optical properties of the organic light emitting diodes (OLEDs) devices with n-doped layer, which is inserted in an effort to reduce the interface barrier between the cathode and the ETL(electron transport layer). In order to anlayze the electrical and optical characteristics such as the transport behavior of carriers, recombination kinetics, and emission property, we undertake the finite element method (FEM) in OLEDs. Our model includes Poisson’s equation, continuity equation to account for behavior of electrons and holes and the exciton continuity/transfer equation to account for recombination of carriers. We employ the multilayer structure that consists of indium tin oxide (ITO); 2, 2’, 7, 7’ –tetrakis (N, N-diphenylamine) - 9, 9’- spirobi-fluorene (S-TAD); 4, 4’- bis (2,2’- diphenylvinyl) - 1,1’- spirobiphenyl (S-DPVBi); tris (8-quinolinolato) aluminium (Alq3); calsium(Ca).

Numerical study for increasement of low frequency sound insulation of double-panel structure using sonic crystals with distributed Helmholtz resonators

2019 ◽  
Vol 33 (14) ◽  
pp. 1950138
Author(s):  
Myong-Jin Kim
Keyword(s):  
Free Space ◽  
Transmission Loss ◽  
Numerical Study ◽  
Low Frequency ◽  
Helmholtz Resonator ◽  
Sound Insulation ◽  
The Finite Element Method ◽  
Helmholtz Resonators ◽  
Sonic Crystal ◽  
Sonic Crystals

Numerical simulations of the sound transmission loss (STL) of a double-panel structure (DPS) with sonic crystal (SC) comprised of distributed local resonators are presented. The Local Resonant Sonic Crystal (LRSC) consists of “C”-shaped Helmholtz resonator columns with different resonant frequencies. The finite element method is used to calculate the STL of such a DPS. First, the STLs of LRSC in free space and the DPS with LRSC are calculated and compared. It is shown that the sound insulations of the local resonators inserted in the double panel are higher than that in free space for the same size of the SCs and the same number of columns. Next, STL of the DPS in which the SC composed of three columns of local resonators having the same outer and inner diameters but different slot widths are calculated, and a reasonable arrangement order is determined. Finally, the soundproofing performances of DPS with distributed LRSC are compared with the case of insertion of general cylindrical SC for SC embedded in glass wool and not. The results show that the sound insulation of the DPS can be significantly improved in the low frequency range while reducing the total mass without increasing the thickness.

scholarly journals Well-posedness of a non-local model for material flow on conveyor belts

2020 ◽  
Vol 54 (2) ◽  
pp. 679-704 ◽  
Author(s):  
Elena Rossi ◽  
Jennifer Weißen ◽  
Paola Goatin ◽  
Simone Göttlich
Keyword(s):  
Material Flow ◽  
Numerical Study ◽  
Approximate Solutions ◽  
Approximation Schemes ◽  
Lipschitz Continuous ◽  
Flux Function ◽  
Local Material ◽  
Uniqueness Of The Solution ◽  
Non Local ◽  
Volume Approximation

In this paper, we focus on finite volume approximation schemes to solve a non-local material flow model in two space dimensions. Based on the numerical discretisation with dimensional splitting, we prove the convergence of the approximate solutions, where the main difficulty arises in the treatment of the discontinuity occurring in the flux function. In particular, we compare a Roe-type scheme to the well-established Lax–Friedrichs method and provide a numerical study highlighting the benefits of the Roe discretisation. Besides, we also prove the L1-Lipschitz continuous dependence on the initial datum, ensuring the uniqueness of the solution.

scholarly journals Graded and Anisotropic Porous Materials for Broadband and Angular Maximal Acoustic Absorption

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4605
Author(s):  
Théo Cavalieri ◽  
Jean Boulvert ◽  
Gwénaël Gabard ◽  
Vicent Romero-García ◽  
Marie Escouflaire ◽  
...  
Keyword(s):  
Porous Materials ◽  
Sound Absorption ◽  
Effective Properties ◽  
Numerical Study ◽  
Optimization Technique ◽  
Single Frequency ◽  
Acoustic Absorption ◽  
Graded Material ◽  
Manufacturing Techniques ◽  
Designed Materials

The design of graded and anisotropic materials has been of significant interest, especially for sound absorption purposes. Together with the rise of additive manufacturing techniques, new possibilities are emerging from engineered porous micro-structures. In this work, we present a theoretical and numerical study of graded and anisotropic porous materials, for optimal broadband and angular absorption. Through a parametric study, the effective acoustic and geometric parameters of homogenized anisotropic unit cells constitute a database in which the optimal anisotropic and graded material will be searched for. We develop an optimization technique based on the simplex method that is relying on this database. The concepts of average absorption and diffuse field absorption coefficients are introduced and used to maximize angular acoustic absorption. Numerical results present the optimized absorption of the designed anisotropic and graded porous materials for different acoustic targets. The designed materials have anisotropic and graded effective properties, which enhance its sound absorption capabilities. While the anisotropy largely enhances the diffuse field absorbing when optimized at a single frequency, graded properties appear to be crucial for optimal broadband diffuse field absorption.

scholarly journals Gurney Flap Implementation on a DU91W250 Airfoil

Proceedings ◽  
2018 ◽  
Vol 2 (23) ◽  
pp. 1448 ◽  
Author(s):  
Iñigo Aramendia ◽  
Aitor Saenz-Aguirre ◽  
Unai Fernandez-Gamiz ◽  
Ekaitz Zulueta ◽  
Jose Manuel Lopez-Guede ◽  
...  
Keyword(s):  
Flow Control ◽  
Numerical Study ◽  
Lift Coefficient ◽  
Optimization Technique ◽  
Electrical Power ◽  
Aerodynamic Performance ◽  
Control Element ◽  
Mechanical Fatigue ◽  
Gurney Flap ◽  
Fatigue Loads

The increasing capability of Wind Turbine (WT) based power generation systems has derived in an increment of the WT rotor diameter, i.e., longer rotor blades. This results in an increase of the electrical power generated but also in instabilities in the operation of the WT, especially due to the mechanical fatigue loads generated in its elements. In this context, flow control has appeared as a solution to improve the aerodynamic performance of the blades. These devices not only increase lift coefficient but also reduce mechanical fatigue loads. This paper presents a detailed numerical analysis of the effects of placing a passive flow control element, a Gurney Flap (GF), in a DU91W250 airfoil. Moreover, a numerical study of the influence of the GF length on the aerodynamic performance of the blade has been carried out. This study is considered as a basis for the development of an optimization technique of the GF length for long WT blades.

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