Simulation Of Thermal Stresses, Voids And Fracture At The GaAs/Ceramic Interface

1995 ◽  
Vol 409 ◽  
Author(s):  
Nickolaos Strifas ◽  
Aris Christou
Keyword(s):  
Finite Element ◽  
Thermal Management ◽  
Thermal Stresses ◽  
Temperature Cycling ◽  
Analysis Method ◽  
Element Analysis ◽  
Temperature Changes ◽  
Die Attach ◽  
Element Simulation ◽  
Reliable Performance

AbstractStresses induced at the GaAs-Al2O3 interface by large ΔT excursions have been investigated by finite element simulation and have been correlated with experimental results. The effects of power and temperature cycling on crack propagation at the die attach are investigated. The FEA (finite element analysis) method is used to simulate the effect of die attach voids on the peak surface temperature and on the die stresses. These voids in the die attach are identified to be the major cause of die cracking. It was found that stresses developed on the die because of the environmental temperature changes and their dissipation as part of an effective thermal management is necessary to ensure reliable performance.

Die Attach Adhesion and Void Formation at the Gaas Substrate Interface

1994 ◽  
Vol 356 ◽  
Author(s):  
Nickolaos Strifas ◽  
Aris Christou
Keyword(s):  
Stress Relaxation ◽  
Void Growth ◽  
Thermal Stresses ◽  
Local Stress ◽  
Temperature Cycling ◽  
Void Volume ◽  
Exponential Relationship ◽  
Element Analysis ◽  
Substrate Interface ◽  
Die Attach

AbstractA model is constructed to consider the stresses (analytically and with Finite Element Analysis (MiA)) which result from the thermal mismatch between the die and the substrate. FHA is used to simulate thermal stresses induced from temperature cycling with voids and without voids in the die-attach at the die-substrate interface. Local stress concentration caused by voids is found to be dependent on the location of the voids. The presence of an edge void at the die-attach interface changes the local stress and creates a longitudinal stress field. It is also observed that for die-attachment without voids or some center voids there will be no cracking whereas specimens with voids near the edge of the die are likely to have vertical die cracks. Using the void growth, stress relaxation equations, the void growth is simulated yielding an exponential relationship to void grow th and a saturation of void volume w ith time. Stress relaxation and void growth during cool down are simulated, once the material parameters and cooling rates are known. It yields a time dependence of the relative void volume (exponential decay).

Finite Element Analysis of Different Outlet Diameter on Fluidic Gyroscope Performance

2014 ◽  
Vol 945-949 ◽  
pp. 1920-1923
Author(s):  
Jing Bo Chen ◽  
Lin Hua Piao ◽  
Jing Jing Zhao ◽  
Xia Ding
Keyword(s):  
Finite Element ◽  
Model Building ◽  
Two Dimensional ◽  
Dimensional Model ◽  
Airflow Velocity ◽  
Element Analysis ◽  
Temperature Changes ◽  
Equation Solving ◽  
Airflow Distribution ◽  
Element Simulation

In this paper, airflow of two different outlet diameters are analyzed contrastively of fluidic gyroscope. Using ANSYS-FLOTRAN CFD software, the finite element simulation is conducted by a series of procedures, such as two-dimensional model building of gyroscope, meshing, loads applying and equation solving, and two dimensional airflow distribution of different outlet diameters in sensitive element are calculated. The results show that, velocity at the outlet Vsum=0.53872m/s which diameter of outlet d=3mm, and which is 35.9% of velocity of the inlet, airflow velocity in the outlet increases by 7.4% than d=4mm at the outlet. It accelerates velocity of fluidic beam without any vortex increases in sensitive cavity when d=3mm, and it also increases thermal wires temperature changes and improves the sensitivity of fluidic gyroscope.

Finite Element Analysis of Slider in High-Speed Horizontal NC Center

2011 ◽  
Vol 225-226 ◽  
pp. 43-46 ◽  
Author(s):  
Ming Cong ◽  
Tao Han ◽  
Qiang Zhao ◽  
Tie Jun Lan ◽  
Xiu Yong Ju
Keyword(s):  
Boundary Condition ◽  
Finite Element ◽  
High Speed ◽  
Simulation Analysis ◽  
The Other ◽  
Analysis Method ◽  
Great Role ◽  
Original Design ◽  
Element Analysis ◽  
Element Simulation

Slider is one of the most important parts in High-Speed Horizontal Machining NC center, it plays a great role in the performance of static and dynamic. In order to assure the working accuracy and dynamic characters, slider must be analyzed to verify the reasonable of original design. According to the structure of slider and based on the theoretical and finite element simulation analysis method, a more reasonable boundary condition is carried out. To be noted that in this paper a method using the conception of combination is introduced. On the other hand the counterforce can be more accurate than before and it makes the following analysis easier.

Finite Element Simulation of Formed Steel Components

2014 ◽  
Vol 622-623 ◽  
pp. 632-642
Author(s):  
Stephen Akinlabi ◽  
Francesco Pietra ◽  
Esther Titilayo Akinlabi
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Thermal Stresses ◽  
Geometrical Shape ◽  
Element Analysis ◽  
Steel Sheets ◽  
Element Simulation ◽  
The Finite Element Analysis ◽  
Mechanical Press ◽  
Commercial Package

Forming is a manufacturing process by which the geometrical shape and size of sheet and plate metals are changed by means of either an external force using mechanical presses and dies or induced thermal stresses by external heat. This study reports on the finite element analysis of mechanically formed steel components using the ANSYS commercial package version 14.5. The samples of the steel sheets were mechanically formed to about 120 mm curvatures using a 20 ton capacity eccentric mechanical press at room temperature. The results showed that the steel samples were successfully formed to the curvature of about 120 mm and the finite element modelled results confirmed the experimental measured curvature. Key words: Forming, Mechanical presses, Finite Element Simulation and Sheets.

scholarly journals Sinterconnects: All-Copper Top-Side Interconnects Based on Copper Sinter Paste for Power Module Packaging

Energies ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2176
Author(s):  
Ali Roshanghias ◽  
Perla Malago ◽  
Jaroslaw Kaczynski ◽  
Timothy Polom ◽  
Jochen Bardong ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Thermal Management ◽  
Electrical Contact ◽  
Power Electronic ◽  
Power Module ◽  
Element Analysis ◽  
Ohmic Losses ◽  
Die Attach ◽  
Wire Bonds

Copper sinter paste has been recently established as a robust die-attach material for high -power electronic packaging. This paper proposes and studies the implementation of copper sinter paste materials to create top-side interconnects, which can substitute wire bonds in power packages. Here, copper sinter paste was exploited as a fully printed interconnect and, additionally, as a copper clip-attach. The electrical and thermal performances of the copper-sinter paste interconnections (“sinterconnects”) were compared to a system with wire bonds. The results indicate comparable characteristics of the sinterconnect structures to the wire-bonded ones. Moreover, the performance of copper sinterconnects in a power module was further quantified at higher load currents via finite element analysis. It was identified that the full-area thermal and electrical contact facilitated by the planar sinterconnects can reduce ohmic losses and enhance the thermal management of the power packages.

Finite Element Analysis of Nozzle Dimension Influence on Fluidic Gyroscope Performance

2013 ◽  
Vol 756-759 ◽  
pp. 4690-4693
Author(s):  
Jing Bo Chen ◽  
Lin Hua Piao ◽  
Jin Tang
Keyword(s):  
Finite Element ◽  
Sensitive Element ◽  
Model Building ◽  
Large Diameter ◽  
Small Diameter ◽  
Two Dimensional ◽  
Element Analysis ◽  
Temperature Changes ◽  
Equation Solving ◽  
Element Simulation

In this paper, research the influence on nozzle dimension in the sensitive element of fluidic gyroscope. Airflow of two different nozzle dimensions is analyzed contrastively in the sensitive element of fluidic gyroscope. Using ANSYS-FLOTRAN CFD software, the finite element simulation is conducted by a series of procedures, such as two-dimensional model building of fluidic gyroscope, meshing, loads applying and equation solving. The two dimensional airflow distributions of different nozzle diameters in sensitive element of fluidic gyroscope are calculated. The results show that, compared with large diameter and small diameter nozzle of fluidic gyroscope, airflow velocity in the outlet increases by 10.1%, and 31.3% of velocity in the nozzle in large diameter nozzle. It promotes airflow circulation and reduces airflow accumulation in the sensitive cavity without any vortex increase in large nozzle, it increases thermal wires temperature changes and improves the resolution and sensitivity of fluidic gyroscope.

Analysis of magnetic force and dynamic characteristic for non-contact permanent magnet linear drive device

2020 ◽  
Vol 64 (1-4) ◽  
pp. 1337-1345
Author(s):  
Chuan Zhao ◽  
Feng Sun ◽  
Junjie Jin ◽  
Mingwei Bo ◽  
Fangchao Xu ◽  
...  
Keyword(s):  
Finite Element ◽  
Permanent Magnet ◽  
Dynamic Characteristic ◽  
Driving Force ◽  
Magnetic Circuit ◽  
Response Speed ◽  
Computation Method ◽  
Element Analysis ◽  
Element Simulation ◽  
The Relationship

This paper proposes a computation method using the equivalent magnetic circuit to analyze the driving force for the non-contact permanent magnet linear drive system. In this device, the magnetic driving force is related to the rotation angle of driving wheels. The relationship is verified by finite element analysis and measuring experiments. The result of finite element simulation is in good agreement with the model established by the equivalent magnetic circuit. Then experiments of displacement control are carried out to test the dynamic characteristic of this system. The controller of the system adopts the combination control of displacement and angle. The results indicate that the system has good performance in steady-state error and response speed, while the maximum overshoot needs to be reduced.

Redrawing Operation a Star Shape from Cylindrical Shape Using Experimental and FE Analysis

2020 ◽  
Vol 38 (1A) ◽  
pp. 25-32
Author(s):  
Waleed Kh. Jawad ◽  
Ali T. Ikal
Keyword(s):  
Finite Element ◽  
Effective Strain ◽  
Element Model ◽  
Cylindrical Shape ◽  
Element Analysis ◽  
Punch Force ◽  
Maximum Value ◽  
Element Simulation ◽  
Blank Sheet ◽  
The Finite Element Model

The aim of this paper is to design and fabricate a star die and a cylindrical die to produce a star shape by redrawing the cylindrical shape and comparing it to the conventional method of producing a star cup drawn from the circular blank sheet using experimental (EXP) and finite element simulation (FES). The redrawing and drawing process was done to produce a star cup with the dimension of (41.5 × 34.69mm), and (30 mm). The finite element model is performed via mechanical APDL ANSYS18.0 to modulate the redrawing and drawing operation. The results of finite element analysis were compared with the experimental results and it is found that the maximum punch force (39.12KN) recorded with the production of a star shape drawn from the circular blank sheet when comparing the punch force (32.33 KN) recorded when redrawing the cylindrical shape into a star shape. This is due to the exposure of the cup produced drawn from the blank to the highest tensile stress. The highest value of the effective stress (709MPa) and effective strain (0.751) recorded with the star shape drawn from a circular blank sheet. The maximum value of lamination (8.707%) is recorded at the cup curling (the concave area) with the first method compared to the maximum value of lamination (5.822%) recorded at the cup curling (the concave area) with the second method because of this exposure to the highest concentration of stresses. The best distribution of thickness, strains, and stresses when producing a star shape by

Use of the Finite Element Analysis Method in Pedodontics

2018 ◽  
Vol 55 (4) ◽  
pp. 666-675
Author(s):  
Mihaela Tanase ◽  
Dan Florin Nitoi ◽  
Marina Melescanu Imre ◽  
Dorin Ionescu ◽  
Laura Raducu ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Structural Model ◽  
Analysis Method ◽  
Ansys Software ◽  
Concentrated Force ◽  
Element Analysis ◽  
Finite Element Analysis Method ◽  
The Finite Element Analysis ◽  
Solid Type

The purpose of this study was to determinate , using the Finite Element Analysis Method, the mechanical stress in a solid body , temporary molar restored with the self-curing GC material. The originality of our study consisted in using an accurate structural model and applying a concentrated force and a uniformly distributed pressure. Molar structure was meshed in a Solid Type 45 and the output data were obtained using the ANSYS software. The practical predictions can be made about the behavior of different restorations materials.

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