Design of Periodic Microstructural Materials by Using Evolutionary Structural Optimization Method

2008 ◽  
Vol 32 ◽  
pp. 279-283 ◽  
Author(s):  
Sachin Patil ◽  
Shi Wei Zhou ◽  
Qing Li
Keyword(s):  
Structural Optimization ◽  
Periodic Boundary ◽  
Material Design ◽  
Periodic Boundary Conditions ◽  
Optimization Method ◽  
Least Square ◽  
Periodic Composites ◽  
Evolutionary Structural Optimization ◽  
The Difference ◽  
Optimal Material

Despite significant success in developing various periodic composites, the challenge remains how to more efficiently design the base cell so that one or more physical properties can be attained. In this paper, the material design problem is formulated in a form of the least square of the difference between the targeted and designed values. By minimizing the objective subject to volume constraints and periodic boundary conditions, an optimal material distribution in base cell can be generated. Different from existing methods, this paper shows how to use the Evolutionary Structural Optimization (ESO) method to design composite material attaining to thermal conductivity defined by the Hashin-Strikman (H-S) bounds. The effectiveness of this method is demonstrated through several 2D examples, agreeing well with commonly known benchmarking microstructures.

Truss Optimization Based on the Evolutionary Structural Optimization

2014 ◽  
Vol 915-916 ◽  
pp. 281-284
Author(s):  
Xing Guo Hu ◽  
He Ming Cheng
Keyword(s):  
Structural Optimization ◽  
Stress Ratio ◽  
Optimization Method ◽  
Truss Optimization ◽  
Ratio Method ◽  
Engineering Optimization ◽  
Structural Topology ◽  
Evolutionary Structural Optimization ◽  
Optimization Principle ◽  
Topology Optimization Method

The Evolutionary Structural Optimization (ESO) as an important structural topology optimization method has been widely used in many fields of engineering optimization. However, due to some technical constraints, the use of ESO for the truss optimization is relatively less. A method for truss optimization that combines the ESO method and the Stress Ratio method is proposed in this paper. This method solves the problems of ESO for truss optimization that the sectional area of bars cannot be changed and the speed of optimization cannot be easily controlled. It can be widely used in truss optimization and can get the same good result as other methods (such as GA and SA, etc.). Furthermore, the method proposed in this paper has the advantage that it can be easily programmed in the commercial software (such as Ansys and Abaqus, etc.) owing to its relatively simple optimization principle.

scholarly journals HOLOGRAPHIC GEOMETRIC ENTROPY AT FINITE TEMPERATURE FROM BLACK HOLES IN GLOBAL ANTI-DE SITTER SPACES

2012 ◽  
Vol 27 (09) ◽  
pp. 1250048 ◽  
Author(s):  
IBRAHIMA BAH ◽  
LEOPOLDO A. PANDO ZAYAS ◽  
CÉSAR A. TERRERO-ESCALANTE
Keyword(s):  
Field Theory ◽  
Black Holes ◽  
Conformal Field Theory ◽  
Periodic Boundary ◽  
Entanglement Entropy ◽  
Periodic Boundary Conditions ◽  
Two Dimensional ◽  
De Sitter ◽  
Conformal Field ◽  
The Difference

Using a holographic proposal for the geometric entropy we study its behavior in the geometry of Schwarzschild black holes in global AdSp for p = 3, 4, 5. Holographically, the entropy is determined by a minimal surface. On the gravity side, due to the presence of a horizon on the background, generically there are two solutions to the surfaces determining the entanglement entropy. In the case of AdS3, the calculation reproduces precisely the geometric entropy of an interval of length l in a two-dimensional conformal field theory with periodic boundary conditions. We demonstrate that in the cases of AdS4 and AdS5 the sign of the difference of the geometric entropies changes, signaling a transition. Euclideanization implies that various embedding of the holographic surface are possible. We study some of them and find that the transitions are ubiquitous. In particular, our analysis renders a very intricate phase space, showing, for some ranges of the temperature, up to three branches. We observe a remarkable universality in the type of results we obtain from AdS4 and AdS5.

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