Thermal-mechanical analysis of packaged power amplifiers based on heterogeneous integrations using photosensitive BCB

Author(s):  
Rong-Liang Cai ◽  
Cheng-Rui Zhang ◽  
Liang Zhou
2014 ◽  
Vol 18 (suppl.1) ◽  
pp. 139-148
Author(s):  
Tarek Aburuga ◽  
Aleksandar Sedmak ◽  
Zoran Radakovic

The effect of the residual stresses and strains is one of the most important parameter in the structure integrity assessment. A finite element model is constructed in order to simulate the multi passes mismatched submerged arc welding SAW which used in the welded tensile test specimen. Sequentially coupled thermal mechanical analysis is done by using ABAQUS software for calculating the residual stresses and distortion due to welding. In this work, three main issues were studied in order to reduce the time consuming during welding simulation which is the major problem in the computational welding mechanics (CWM). The first issue is dimensionality of the problem. Both two- and three-dimensional models are constructed for the same analysis type, shell element for two dimension simulation shows good performance comparing with brick element. The conventional method to calculate residual stress is by using implicit scheme that because of the welding and cooling time is relatively high. In this work, the author shows that it could use the explicit scheme with the mass scaling technique, and time consuming during the analysis will be reduced very efficiently. By using this new technique, it will be possible to simulate relatively large three dimensional structures.


2000 ◽  
Author(s):  
Hongyan Zhang ◽  
Jacek Senkara ◽  
Xin Wu

Abstract In this paper mechanical aspects of cracking during single- and multi-spot welding of AA5754 was investigated by both experimental and analytical approaches. The impact of mechanical loading on crack initiation and propagation was studied with the consideration of various process parameters including the loading imposed by electrodes, the formation of liquid nugget, and constraining factors during and after welding. Tensile properties of AA5754 and their dependence on the temperature were tested at room and up to solidus temperatures, in order to provide a reference of cracking stress. Thermal-mechanical analysis was conducted based on the temperature field around the nugget and the state of stress encountered during welding. This analysis revealed that tensile stress might build up in the vicinity of the nugget during cooling, thus explained the experimental observation. General guidelines for suppressing cracking were proposed, i.e. to provide sufficient constraint around the weld spot during and after welding.


2018 ◽  
Vol 332 ◽  
pp. 297-306 ◽  
Author(s):  
Yangbin Deng ◽  
Yingwei Wu ◽  
Cheng Gong ◽  
Dalin Zhang ◽  
Wenxi Tian ◽  
...  

1986 ◽  
Vol 76 ◽  
Author(s):  
C. W. Wilkins ◽  
H. E. Bair ◽  
M. G. Chan ◽  
R. S. Hutton

ABSTRACTWe have studied some of the physical and mechanical properties of cyclized polybutadiene (CBR) dielectrics by dynamic mechanical analysis, thermal mechanical analysis, thermogravimetry, infrared analysis, and differential scanning calorimetry. Of interest is the difference in properties between thin (<30 μm) films which have been cured under vacuum and those which have been cured in air. Our results indicate that curing under vacuum prevents oxidation and reduces crosslinking. Vacuum cured films have 20% smaller moduli and 200 lower glass transition temperature than do films produced in air.


Minerva ◽  
2020 ◽  
Vol 1 (1) ◽  
pp. 43-57
Author(s):  
Saul Jaimes

A thermal-mechanical analysis of the behavior of the segments of the rollers of the briquetting machines is carried out due to the effect of thermal shock and efforts exerted on the part. It is intended to obtain the main causes that generate this problem, through a mechanical analysis that simulated the behavior in the presence of several thermal gradients. The purpose of the study is to reduce maintenance costs and the continuous replacement and repair of segments, as well as losses in tons of production due to the failure that are of great impact to the industry. This investigation allows us to know to what extent the operating parameters, such as: material temperature, pressure, torque, speed of the rollers influence the life of the segments according to their manufacturing material and based on these the behavior is simulated during the briquetting process. Keywords: Simulation, Finite element, Briquettes. [1]D. F. Pinzón, «Diseño óptimo de Sistemas de Distribución,» Universidad Nacional de Colombia, Bogotá, 2014. [2]F. A. Mendoza Lameda, «Diseño multiobjetivo y multietapa de sistemas de distribución de energía eléctrica aplicando algoritmos evolutivos,» Universidad de Zaragoza, Zaragoza, 2010. [3]L. Miró Hernández y R. Vizcón Toledo, «Sistema Hibrido Propuesto Para la Generación de Electricidad en un Policlínico,» Revista Avanzada Científica, vol. 9, nº 2, pp. 50-56, 2006. [4]J. Lagunas M., C. Ortega S. y P. Caratozzolo M., «Control supervisorio para sistemas híbridos de geración eléctrica basado en lógica difusa,» Boletin UE, Monterrey, 2005. [5]J. L. Bernal Agustín, «Aplicación de algoritmos genéticos al diseño óptimo de sistemas de distribución de energía eléctrica,» Universidad de Zaragoza, Zaragoza, 1998. [6]V. MIranda, J. V. Ranito y L. Proenca, «Genetic Algorithms in Optimal Multistage Distribution Network Planning, » IEEE, Porto, 1994. [7]I. Ramirez-Rosado y J. Dominguez-Navarro, «Computer Aided Desing of Power Distribution Systems: Multiobjective Mathematical Simulations» International Journal of Power and Energy Systems, vol. 19, nº 4, pp. 1801-1810, 2004.


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