Applications of a Decomposed Analysis Procedure for Area-Array Packages

2000 ◽  
Vol 123 (2) ◽  
pp. 132-140
Author(s):  
Terrace B. Thompson ◽  
Ganesh Subbarayan

The goals of the present paper are to apply the recently developed decomposed analysis procedure using a computer code developed in this study. The decomposed technique enables one to determine the equilibrium configuration of electronic packages with significant computational efficiency at a reasonable accuracy. Further, it allows the independent analysis of the subsystems enabling “reusable” modules in a manner analogous to the object-oriented programming paradigm of modern computer languages. The code described here uses a nonlinear optimization procedure that ensures the approximate satisfaction of the balance of mechanical energy. The developed procedure is demonstrated on a variety of two- and three-dimensional hypothetical and “real-world” electronic packages. It is shown that with the use of the decomposed solution methodology, for a 225 I/O PBGA package, a speedup of nearly seven times is achieved at an accuracy loss in displacements of approximately 5.5 percent. It is also shown that the calculated peak shear displacements agree very well with experimental measurements made using laser moire´ interferometry. Since the analysis procedure is independent of the number of solder interconnects, significantly larger time savings are expected for larger packages.

1999 ◽  
Vol 122 (1) ◽  
pp. 13-19 ◽  
Author(s):  
Anand M. Deshpande ◽  
Ganesh Subbarayan

The goals of the present paper are to develop and demonstrate an efficient technique for the design/analysis of electronic packages through a novel decomposition procedure. The ultimate utility of these techniques is to enable quick and accurate design decisions at system-level, during package development by enabling one to develop a reusable library of modules in a manner analogous to the object-oriented programming paradigm of modern computer science. The methodology allows simultaneous design as well as domain decomposition and is based on a nonlinear optimization procedure that ensures the approximate satisfaction of the principle of virtual work. The developed procedure is demonstrated on a 5×5 hypothetical arrayed package. It is shown that with the use of the decomposed solution methodology, approximately 350 percent improvement in computational efficiency is achieved at an accuracy loss of only 6 percent. A windows-based graphical program founded on an artificial neural network model for predicting life given shear and axial deformation of solder joints was also developed. This neural network encapsulates the results of finite element analyses and predicts life for a given loading in a fraction of a second. [S1043-7398(00)00201-2]


Author(s):  
Deepika Saini ◽  
Sanoj Kumar ◽  
Manoj K. Singh ◽  
Musrrat Ali

AbstractThe key job here in the presented work is to investigate the performance of Generalized Ant Colony Optimizer (GACO) model in order to evolve the shape of three dimensional free-form Non Uniform Rational B-Spline (NURBS) curve using stereo (two) views. GACO model is a blend of two well known meta-heuristic optimization algorithms known as Simple Ant Colony and Global Ant Colony Optimization algorithms. Basically, the work talks about the solution of NURBS-fitting based reconstruction process. Therefore, GACO model is used to optimize the NURBS parameters (control points and weights) by minimizing the weighted least-square errors between the data points and the fitted NURBS curve. The algorithm is applied by first assuming some pre-fixed values of NURBS parameters. The experiments clearly show that the optimization procedure is a better option in a case where good initial locations of parameters are selected. A detailed experimental analysis is given in support of our algorithm. The implemented error analysis shows that the proposed methodology perform better as compared to the conventional methods.


2015 ◽  
Vol 2 (11) ◽  
pp. 150496 ◽  
Author(s):  
Fabian Westhauser ◽  
Christian Weis ◽  
Melanie Hoellig ◽  
Tyler Swing ◽  
Gerhard Schmidmaier ◽  
...  

Bone tissue engineering and bone scaffold development represent two challenging fields in orthopaedic research. Micro-computed tomography (mCT) allows non-invasive measurement of these scaffolds’ properties in vivo . However, the lack of standardized mCT analysis protocols and, therefore, the protocols’ user-dependency make interpretation of the reported results difficult. To overcome these issues in scaffold research, we introduce the Heidelberg-mCT-Analyzer. For evaluation of our technique, we built 10 bone-inducing scaffolds, which underwent mCT acquisition before ectopic implantation (T0) in mice, and at explantation eight weeks thereafter (T1). The scaffolds’ three-dimensional reconstructions were automatically segmented using fuzzy clustering with fully automatic level-setting. The scaffold itself and its pores were then evaluated for T0 and T1. Analysing the scaffolds’ characteristic parameter set with our quantification method showed bone formation over time. We were able to demonstrate that our algorithm obtained the same results for basic scaffold parameters (e.g. scaffold volume, pore number and pore volume) as other established analysis methods. Furthermore, our algorithm was able to analyse more complex parameters, such as pore size range, tissue mineral density and scaffold surface. Our imaging and post-processing strategy enables standardized and user-independent analysis of scaffold properties, and therefore is able to improve the quantitative evaluations of scaffold-associated bone tissue-engineering projects.


2012 ◽  
Vol 42 (1) ◽  
pp. 18-38 ◽  
Author(s):  
G. Roullet ◽  
J. C. McWilliams ◽  
X. Capet ◽  
M. J. Molemaker

Abstract High-resolution simulations of β-channel, zonal-jet, baroclinic turbulence with a three-dimensional quasigeostrophic (QG) model including surface potential vorticity (PV) are analyzed with emphasis on the competing role of interior and surface PV (associated with isopycnal outcropping). Two distinct regimes are considered: a Phillips case, where the PV gradient changes sign twice in the interior, and a Charney case, where the PV gradient changes sign in the interior and at the surface. The Phillips case is typical of the simplified turbulence test beds that have been widely used to investigate the effect of ocean eddies on ocean tracer distribution and fluxes. The Charney case shares many similarities with recent high-resolution primitive equation simulations. The main difference between the two regimes is indeed an energization of submesoscale turbulence near the surface. The energy cycle is analyzed in the (k, z) plane, where k is the horizontal wavenumber. In the two regimes, the large-scale buoyancy forcing is the primary source of mechanical energy. It sustains an energy cycle in which baroclinic instability converts more available potential energy (APE) to kinetic energy (KE) than the APE directly injected by the forcing. This is due to a conversion of KE to APE at the scale of arrest. All the KE is dissipated at the bottom at large scales, in the limit of infinite resolution and despite the submesoscales energizing in the Charney case. The eddy PV flux is largest at the scale of arrest in both cases. The eddy diffusivity is very smooth but highly nonuniform. The eddy-induced circulation acts to flatten the mean isopycnals in both cases.


Author(s):  
S. V. Subramanian ◽  
R. Bozzola ◽  
Louis A. Povinelli

The performance of a three dimensional computer code developed for predicting the flowfield in stationary and rotating turbomachinery blade rows is described in this study. The four stage Runge-Kutta numerical integration scheme is used for solving the governing flow equations and yields solution to the full, three dimensional, unsteady Euler equations in cylindrical coordinates. This method is fully explicit and uses the finite volume, time marching procedure. In order to demonstrate the accuracy and efficiency of the code, steady solutions were obtained for several cascade geometries under widely varying flow conditions. Computed flowfield results are presented for a fully subsonic turbine stator and a low aspect ratio, transonic compressor rotor blade under maximum flow and peak efficiency design conditions. Comparisons with Laser Anemometer measurements and other numerical predictions are also provided to illustrate that the present method predicts important flow features with good accuracy and can be used for cost effective aerodynamic design studies.


2011 ◽  
Vol 201-203 ◽  
pp. 830-835
Author(s):  
Chang Gao Xia ◽  
Jian Kuan Su ◽  
Mao Hui Pan

This paper presents an integrated method, which is based on the CAD/CAE, for engine crankshaft design. A parametric modeling system of engine crankshaft is established with the CATIA secondary development tools. Taking advantage of the finite element analysis procedure of engine crankshaft strength which is programmed with ANSYS APDL programming language, the parametric loading, automatic solution and result analysis of the crankshaft strength can be realized. Integrating the parametric modeling system of engine crankshaft and the special finite element analysis procedure of the engine crankshaft strength, the three-dimensional digital model of the crankshaft can be generated rapidly. By changing the structure dimension, the crankshaft series design is achieved and the design and analysis can be improved. Therefore, it is helpful to improve the design quality and efficiency of crankshaft and shorten the design cycle.


Author(s):  
Guomin Ji ◽  
Bernt J. Leira ◽  
Svein Sævik ◽  
Frank Klæbo ◽  
Gunnar Axelsson ◽  
...  

This paper presents results from a case study performed to evaluate the residual capacity of a 6″ flexible pipe when exposed to corrosion damages in the tensile armour. A three-dimensional nonlinear finite element model was developed using the computer code MARC to evaluate the increase in mean and dynamic stresses for a given number of damaged inner tensile armor wires. The study also includes the effect of these damages with respect to the associated stresses in the pressure spiral. Furthermore, the implications of a sequence of wire failures with respect to the accumulated time until cross-section failure in a probabilistic sense are addressed.


Author(s):  
Kikuo Fujita ◽  
Shinsuke Akagi

Abstract A Framework of computational design method and model is proposed for layout and geometry design of complicated mechanical systems, which is named “configuration network and its viewing control”. In the method, a design object is represented with a set of declarative relationships among various elements of a system, that is, configurations, which is gradually extended from schematic structure to exact layout and geometry through design process. Since a whole of such configurations forms a too complicated network to compute all together, how to view subparts is controlled based on levels of granularity and width of scope range. Such a configuration network is made to grow and refined through embodying geometry and layout corresponding to a focused subpart with a numerical optimization procedure. The framework has also an ability to flexibly integrate with engineering analysis. Moreover, a design system is implemented with an object-oriented programming technique, and it is applied to a design problem of air conditioner units in order to show the validity and effectiveness of the framework.


2021 ◽  
Author(s):  
Wen Yang ◽  
Lun Zhou ◽  
Junrong Qiu ◽  
Yun Tai

Abstract Three dimensional PWR-core analysis code CORAL is developed by Wuhan Second Ship Design and Research Institute. This code provides basic functions including three-dimensional power distribution, fine power reconstruction, fuel temperature distribution, critical search, control rod worth, reactivity coefficients, burnup and nuclide density distribution, etc. CORAL employ nodal expansion method to solve neutron diffusion equation, and the least square method is used to achieve few group constants, and sub-channel model and one-dimensional heat transfer is used to calculate fuel temperature and coolant density distribution, and burnup distribution and nuclide nuclear density could be obtained by solving macro-depletion and micro-depletion equation. The CORAL code is convenient to update and maintain in consider of modular, object-oriented programming technology. In order to analyze the computational accuracy of the CORAL code in small PWR-core and its capability to deal with heterogeneous, calculation analysis are carried out based on the material and geometry parameters of the SMART core. The core has 57 fuel assemblies, with 8, 20 or 24 gadolinium rods arranged in the fuel assemblies. In this paper, a quantitative comparison and analysis of the small PWR problem calculation results are carried out. Numerical results, including effective multiplication factor, assembly power distribution and pin power distribution, all agree well with the calculation results of OpenMC or Bamboo at both hot zero-power (HZP) and hot full-power (HFP) conditions.


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