Advancement in simulating moisture diffusion in electronic packages under dynamic thermal loading conditions

2017 ◽  
Vol 73 ◽  
pp. 42-53 ◽  
Author(s):  
Jing Wang ◽  
Ruiyang Liu ◽  
Dapeng Liu ◽  
Seungbae Park
Keyword(s):  
Thermal Loading ◽  
Moisture Diffusion ◽  
Electronic Packages ◽  
Loading Conditions

On Moisture Diffusion Modeling Using Thermal-Moisture Analogy

2007 ◽  
Vol 129 (4) ◽  
pp. 421-426 ◽  
Author(s):  
Samson Yoon ◽  
Bongtae Han ◽  
Zhaoyang Wang
Keyword(s):  
Thermal Loading ◽  
Moisture Diffusion ◽  
Loading Conditions ◽  
Diffusion Modeling ◽  
Governing Equations ◽  
Practical Applications ◽  
Diffusion Analysis ◽  
Material Systems ◽  
Single Material

Thermal-moisture analogy schemes for a moisture diffusion analysis are reviewed. Two schemes for practical applications are described using the governing equations of heat and mass diffusions: (1) direct analogy and (2) normalized analogy. The schemes are implemented to define valid domains of application. The results corroborate that the direct analogy is valid only for single-material systems, but the normalized analogy can be extended to multimaterial systems if thermal loading conditions are isothermal, spatially as well as temporally.

Fracture mechanics assessment of divertor vertical target under thermal loading conditions

2019 ◽  
Vol 146 ◽  
pp. 2209-2213 ◽  
Author(s):  
Jae Min Sim ◽  
Sang Yun Je ◽  
Ji-Hoon Kang ◽  
Yoon-Suk Chang
Keyword(s):  
Fracture Mechanics ◽  
Thermal Loading ◽  
Loading Conditions

Numerical Investigations of Phenomena Caused by the Closure and Growth Behavior of Short Cracks Under Thermal Cyclic Loading

2010 ◽  
Author(s):  
Ju¨rgen Rudolph ◽  
Kai Bauerbach ◽  
Michael Vormwald
Keyword(s):  
Cyclic Loading ◽  
Crack Propagation ◽  
Crack Closure ◽  
Thermal Loading ◽  
Hysteresis Loops ◽  
Local Stress ◽  
Damage Parameter ◽  
Loading Conditions ◽  
Propagation Behavior ◽  
Crack Propagation Behavior

Thermal cyclic loading conditions of nuclear power plant components cause local stress-strain hystereses which are considered to be fatigue relevant events. The contributions of the hysteresis-loops to the fatigue process are evaluated using a damage parameter based on the effective cyclic J-integral which also includes the effects of crack closure. The successful application of such a short crack propagation approach essentially depends on the realistic description of the crack closure. In this context a finite element based algorithm is presented to simulate the opening and closure effects under special consideration of thermal cyclic loading conditions. The concept is based on node release and contact mechanisms. The implications of the crack propagation on the temperature at the crack tip are to be considered. In this context, the consequences of the altered temperature profile as the crack propagates have to be taken into account. It is the aim to formulate Newman-type analytical equations in order to incorporate the influence of crack closure into an engineering approach. Furthermore, the peculiarities of transient thermal loading on the crack propagation behavior are considered. The reduced crack propagation rates due to the temperature gradient in the direction of the wall are investigated numerically in order to describe the reduction of the damage contribution and decelerated crack propagation rates. The effects of changing thermal conditions in the wall on the crack propagation behavior are considered within the numerical algorithm.

Calculations for stress-strained state of a panel of a solar array under thermal loading conditions

2005 ◽  
Vol 11 (5-6) ◽  
pp. 103-110 ◽  
Author(s):  
Wang Xiaoyan ◽  
◽  
Yu.A. Pokhyl ◽  
K.V. Koval ◽  
H. Shiyu ◽  
...  
Keyword(s):  
Thermal Loading ◽  
Solar Array ◽  
Strained State ◽  
Loading Conditions

Fatigue Assessment of Nuclear Power Plant Components Subjected to Thermal Cyclic Loading

2009 ◽  
Author(s):  
Kai Bauerbach ◽  
Michael Vormwald ◽  
Ju¨rgen Rudolph
Keyword(s):  
Power Plant ◽  
Nuclear Power Plant ◽  
Nuclear Power ◽  
Thermal Loading ◽  
Hysteresis Loops ◽  
Plastic Behavior ◽  
Loading Conditions ◽  
Material Parameters ◽  
Structural Loading ◽  
Plant Components

Thermal loading conditions of nuclear power plant components cause local stress-strain hystereses. For the fatigue life prediction of nuclear power plant components under thermal cyclic and structural loading a new method based on the local strain approach is to be presented. This method involves finite-element simulations as well as the experience gathered from lifetime assessment methods based on short crack models. The local stresses and strains are obtained from coupled-field FE-analyses. The calculation of the hysteresis-loops relies on appropriate material models and experimentally verified temperature-dependent material parameters in order to describe the elasto-plastic behavior of the material as realistically as necessary. Due to the temperature dependence of the material parameters the resulting hysteresis loops are of non-conventional shapes and similar to those observed under multiaxial nonproportional structural loading. Hence, fatigue methodologies developed for non-proportional loading conditions during the past years bear good prospects for successful application under non-isothermal loading conditions.

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