Lifetime and Reliability Assessment of AlN Substrates Used in Harsh Aeronautic Environments Power Switch Modules

2010 ◽  
Vol 112 ◽  
pp. 113-127 ◽  
Author(s):  
Adrien Zéanh ◽  
Olivier Dalverny ◽  
Moussa Karama ◽  
Arezki Bouzourene
Keyword(s):  
Finite Elements ◽  
External Loading ◽  
Principal Stresses ◽  
Ceramic Substrates ◽  
Ceramic Fracture ◽  
Bending Tests ◽  
Weakest Link ◽  
Power Switch ◽  
Finite Elements Modelling ◽  
Switch Module

This paper presents a Finite Elements Modelling (FEM) based methodology dedicated to the evaluation of the lifetime and the reliability of assemblies involving brittle materials under cyclic loading. It focuses on the particular case of metal bonded Aluminium Nitride (AlN) substrates used in power electronic switch modules. The ceramic fracture criterion was formulated according to the weakest link concept, under Weibull's approach. The material's parameters were determined by running three points bending tests. In order to check the relevancy of the proposed methodology, a non linear thermomechanical Finite Elements Model allowed computing the number of thermal cycles before substrate brittle fracture within a test vehicle, which was then compared to experimental results. Once validated, the methodology was applied to two different configurations of a power switch module, designed for harsh environment aeronautic applications. The corresponding external loading profile was considered to compute and monitor the evolution of the maximal principal stresses within the ceramic substrates whole volumes. Their lifetimes and reliabilities was finally assessed and compared to the applications requirements.

Intelligent bidirectional power switch module for matrix converter applications

2007 ◽  
Author(s):  
J. L. Galvez ◽  
X. Jorda ◽  
M. Vellvehi ◽  
J. Millan ◽  
M. A. Jose-Prieto ◽  
...  
Keyword(s):  
Matrix Converter ◽  
Power Switch ◽  
Switch Module

Finite Elements Modelling of Elastoplastic Structures Using Self-Consistent Constitutive Relation

1991 ◽  
pp. 659-662
Author(s):  
E. Scacciatella ◽  
J. M. Genevaux ◽  
P. Lipinski ◽  
M. Berveiller ◽  
J. M. Detraux ◽  
...  
Keyword(s):  
Finite Elements ◽  
Constitutive Relation ◽  
Self Consistent ◽  
Finite Elements Modelling

scholarly journals Analysis of some key aspects of soil/foundation interaction-Finite elements modelling

2018 ◽  
Vol 149 ◽  
pp. 02019
Author(s):  
Hamidi Ahmed ◽  
Bouafia Ali
Keyword(s):  
Finite Elements ◽  
Threshold Value ◽  
Shallow Foundation ◽  
Threshold Distance ◽  
Saturated Clay ◽  
Foundation Base ◽  
Soil Foundation ◽  
Finite Elements Modelling ◽  
Key Aspects ◽  
Strip Footings

This paper is aimed to contribute to the analysis of three important aspects of soil-foundation interaction, which are not clearly investigated, by means of a detailed parametric study based on a finite elements modelling. The first aspect focuses on the effect of the bedrock proximity on the load-settlement behaviour of a continuous or circular shallow foundation. It was found there exists a threshold distance between the foundation base and the top of the bedrock layer beyond which the foundation behaves as in an infinitely deep medium. The second one deals with the behaviour of shallow foundation on a bi-layered soil where the effect of the underlying layer on the bearing capacity as well as on the settlements depends on the distance between the foundation base and the top of the underlying layer, and beyond a threshold value this effect vanishes. The third aspect studied was the interference between two strip footings installed on saturated clay. It was shown within a threshold distance between these foundations, an important modification of the foundation behaviour may occur. Finally, the numerical results were fitted and interpreted which allowed suggesting simple practical formulae for shallow foundations design.

TN X SN Fatigue Curves for KS Hook and Chain Using Finite Elements Modelling and Model Test

2007 ◽  
Author(s):  
Jose´ Carlos Lima de Almeida ◽  
Ronaldo Rosa Rossi ◽  
Ricardo Sobral
Keyword(s):  
Finite Elements ◽  
Model Test ◽  
Fatigue Curve ◽  
Functional Condition ◽  
Mooring Line ◽  
Hardness Profile ◽  
Mooring Lines ◽  
Finite Elements Modeling ◽  
Predicting Behavior ◽  
Finite Elements Modelling

The new scenario of oil exploration in ultra deep water moves forward to 3000 m, has been putting for the companies that accept this technological challenger significant, border of the techno-scientific knowledge. Therefore, nowadays in this case of ultra deep waters, where the forces above the mooring lines are increase and the use of the new material in Petrobras Floating Production Units, it is necessary the good numerical analyses and experimental test by the mooring line. It appears the need to look for a solution for the problems according to the changes of the polyester rope in the production platform without the bottom extension change and its foundation (fixed point). According to this challenge it was necessary to develop a remote connection and disconnection device. This device is the KS hook and its optimization has been created using the fracture mechanical conception optics and computers tools (FEM and mooring software). There are two conditions to develop this device: one condition is functional and the other is structural. For the functional condition, it’s necessary to create the facilities for handling and installations. For the structural conditions, it is necessary to use the special wrought steel material, treatment for steel characteristic and right geometry. Finite Elements Modeling analyze used the Ansys software, considered the hardness profile material for Minimum Break Load (MBL). The lifetime design is about 25 years for this case and the fatigue analysis considered the residual stress and plasticity for structural device. Previous simulation is especially important in predicting behavior and in the development of new design products before testing. The model was meshed with 3D first order tetrahedral elements solid45. The mesh was sufficiently fine to ensure minimal loss of accuracy in curved geometry. There isn’t a TN fatigue curve (reference API Fatigue curves) for this KS Hook device geometry, in this case become necessary to use the model test to obtain this curve with the extrapolation of the results. The Finite Elements Modeling analyze used with the Material SN Fatigue curve will be used for this validation. Previous simulation is especially important in predicting behavior and in the development of new design products before testing.

Microstructure and Strength of Low Temperature Co-Fired Ceramic Substrates With Channels and Cavities

2008 ◽  
Author(s):  
Yang-Fei Zhang ◽  
Min Miao ◽  
Yu-Feng Jin ◽  
Shu-Lin Bai
Keyword(s):  
Flexural Strength ◽  
Theoretical Calculations ◽  
Aluminum Silicate ◽  
X Ray Diffraction ◽  
Element Analysis ◽  
Ceramic Substrates ◽  
Bending Tests ◽  
Three Point Bending ◽  
Internal Structures ◽  
Fea Simulation

The effect of embedded channels and cavities on the strength of LTCC substrates has been investigated by experiments, theoretical analysis and finite element analysis (FEA) simulation. The fracture behaviors characterized by flexural strength were measured by three-point bending tests and discussed according to the features of the microstructure, which was studied by Scanning Electron Microscope, Energy Spectrum Analysis and X-Ray Diffraction methods. The experimental results show that X and Y-axial channels have little effect on the flexural strength while Z-axial via-hole will greatly lower the strength due to the stress concentration. Two distinct components were observed: particles composed of synthetic corundum and matrix composed of corundum, silica, aluminum, and sodium calcium aluminum silicate. The FEA simulation gave similar results to the experiments and theoretical calculations and proved to be an effective method to predict possible condition of the fracture on substrates with complex internal structures.

Sign in / Sign up

Export Citation Format

Share Document