Nonlinear analysis based optimal design of double-layer grids using enhanced colliding bodies optimization method

2016 ◽  
Vol 58 (3) ◽  
pp. 555-576 ◽  
Author(s):  
A. Kaveh ◽  
M. Moradveisi
Keyword(s):  
Optimal Design ◽  
Nonlinear Analysis ◽  
Double Layer ◽  
Optimization Method ◽  
Colliding Bodies Optimization ◽  
Enhanced Colliding Bodies Optimization

Optimal design of nonlinear large-scale suspendome using cascade optimization

2017 ◽  
Vol 33 (1) ◽  
pp. 3-18 ◽  
Author(s):  
Ali Kaveh ◽  
Masoud Rezaei ◽  
MR Shiravand
Keyword(s):  
Optimal Design ◽  
Large Scale ◽  
Simple Procedure ◽  
Geometry Optimization ◽  
Steel Structures ◽  
Optimization Method ◽  
Scale Space ◽  
Cross Sectional ◽  
Colliding Bodies Optimization ◽  
Design Variables

Large-scale suspendomes are elegant architectural structures which cover a vast area with no interrupting columns in the middle. These domes have attractive shapes which are also economical. Domes are built in a wide variety of forms. In this article, an algorithm is developed for optimum design of domes considering the topology, geometry, and size of member section using the cascade-enhanced colliding bodies optimization method. In large-scale space steel structures, a large number of design variables are involved. The idea of cascade optimization allows a single optimization problem to be tackled in a number of successive autonomous optimization stages. The variables are the optimum height of crown and tubular sections of these domes, the initial strain, the length of the struts, and the cross-sectional areas of the cables in the tensegrity system of domes. The number of joints in each ring and the number of rings are considered for topology optimization of ribbed and Schwedler domes. Weight of the dome is taken as the objective function for minimization. A simple procedure is defined to determine the configuration of the domes. The design constraints are considered according to the provisions of Load and Resistance Factor Design–American Institute of Steel Constitution. In order to investigate the efficiency of the presented method, a large-scale suspendome with more than 2266 members is investigated. Numerical results show that the utilized method is an efficient tool for optimal design of large-scale domes. Additionally, in this article, a topology and geometry optimization for two common ribbed and Schwedler domes are performed to find their optimum graphs considering various spans.

scholarly journals Discrete Optimum Design of Planar Steel Curved Roof and Pitched Roof Portal Frames Using Metaheuristic Algorithms

2021 ◽  
Author(s):  
Ali Kaveh ◽  
Mohammad Iman Karimi Dastjerdi ◽  
Ataollah Zaerreza ◽  
Milad Hosseini
Keyword(s):  
Optimal Design ◽  
Optimum Design ◽  
Population Based ◽  
Colliding Bodies Optimization ◽  
Industrial Buildings ◽  
Enhanced Colliding Bodies Optimization ◽  
Teaching Learning Based Optimization ◽  
Fire Stations ◽  
Teaching Learning ◽  
Discrete Optimum

Portal frames are single-story frame buildings including columns and rafters, and their rafters can be either curved or pitched. These are used widely in the construction of industrial buildings, warehouses, gyms, fire stations, agricultural buildings, hangars, etc. The construction cost of these frames considerably depends on their weight. In the present research, the discrete optimum design of two types of portal frames including planar steel Curved Roof Frame (CRF) and Pitched Roof Frame (PRF) with tapered I-section members are presented. The optimal design aims to minimize the weight of these frame structures while satisfying some design constraints based on the requirements of ANSI/AISC 360-16 and ASCE 7-10. Four population-based metaheuristic optimization algorithms are applied to the optimal design of these frames. These algorithms consist of Teaching-Learning-Based Optimization (TLBO), Enhanced Colliding Bodies Optimization (ECBO), Shuffled Shepherd Optimization Algorithm (SSOA), and Water Strider Algorithm (WSA). Two main objectives are followed in this paper. The first one deals with comparing the optimized weight of the CRF and PRF structures with the same dimensions for height and span in two different span lengths (16.0 m and 32.0 m), and the second one is related to comparing the performance of the considered metaheuristics in the optimum design of these portal frames. The obtained results reveal that CRF is more economical than PRF in the fair comparison. Moreover, comparing the results acquired by SSOA with those of other considered metaheuristics reveals that SSOA has better performance for the optimal design of these portal frames.

scholarly journals Simultaneous Shape and Size Optimization of Double-layer Grids with Nonlinear Behavior

2020 ◽  
Author(s):  
Ali Kaveh ◽  
Mehran Moradveisi
Keyword(s):  
Optimum Design ◽  
Double Layer ◽  
Minimum Weight ◽  
Geometrical Nonlinearity ◽  
Nonlinear Behavior ◽  
Optimization Method ◽  
Size Optimization ◽  
Colliding Bodies Optimization ◽  
Load And Resistance Factor ◽  
Shape And Size

The main aim of this paper is to present a new solution for simultaneous shape and size optimization of double-layer grids. In order to find the optimum design, Enhanced Colliding Bodies Optimization method is applied to the optimum design of the most common examples of double-layer grids, while both material and geometrical nonlinearity are taken into account. The small and big sizes of span length are considered for each type of square grids. The algorithm gets the minimum weight grid by finding the best nodal location in z-direction (height of the structure) and the suitable selection from the list of tube sections available in American Institute of Steel Construction Load and Resistance Factor Design, simultaneously. All examples are optimized with strength and displacement constraints. The numerical results demonstrate the efficiency and robustness of the presented method for solving real-world practical double-layer grids.

3-D optimal design of laminated yoke of billet heater for rolling wire rod using ON/OFF method

2012 ◽  
Vol 61 (1) ◽  
pp. 115-123 ◽  
Author(s):  
Norio Takahashi ◽  
Shunsuke Nakazaki ◽  
Daisuke Miyagi ◽  
Naoki Uchida ◽  
Keiji Kawanaka ◽  
...  
Keyword(s):  
Optimal Design ◽  
Local Heating ◽  
Optimization Method ◽  
Optimal Topology ◽  
Field Problem ◽  
Heating Efficiency ◽  
Magnetic Devices ◽  
Wire Rod ◽  
Magnetic Recording Heads ◽  
Sensitivity Method

3-D optimal design of laminated yoke of billet heater for rolling wire rod using ON/OFF method The optimization method using the ON/OFF sensitivity analysis has an advantage that an epoch-making construction of magnetic circuit may be obtained. Therefore, it is attractive for designers of magnetic devices. We have already developed the ON/OFF method for the optimization of a static magnetic field problem, and the effectiveness is verified by applying it to the optimization of magnetic recording heads. In this paper, the ON/OFF sensitivity method is extended to the optimization of the eddy current problem using the adjoint variable. The newly developed ON/OFF method is applied to the determination of the optimal topology of the yoke of the billet heater for rolling wire rod. As a result, the optimal shape of yoke, which we could not imagine beforehand can be obtained. It is shown that the local heating of the yoke was reduced without decreasing the heating efficiency.

Shape-design optimization of hull structures considering thermal deformation

2013 ◽  
Vol 228 (13) ◽  
pp. 2266-2277
Author(s):  
Myung-Jin Choi ◽  
Min-Geun Kim ◽  
Seonho Cho
Keyword(s):  
Optimal Design ◽  
Design Optimization ◽  
Thermal Deformation ◽  
Parametric Design ◽  
Optimization Method ◽  
Optimization Process ◽  
Design Parameters ◽  
Shape Design ◽  
Shape Design Optimization ◽  
Modified Method

We developed a shape-design optimization method for the thermo-elastoplasticity problems that are applicable to the welding or thermal deformation of hull structures. The point is to determine the shape-design parameters such that the deformed shape after welding fits very well to a desired design. The geometric parameters of curved surfaces are selected as the design parameters. The shell finite elements, forward finite difference sensitivity, modified method of feasible direction algorithm and a programming language ANSYS Parametric Design Language in the established code ANSYS are employed in the shape optimization. The objective function is the weighted summation of differences between the deformed and the target geometries. The proposed method is effective even though new design variables are added to the design space during the optimization process since the multiple steps of design optimization are used during the whole optimization process. To obtain the better optimal design, the weights are determined for the next design optimization, based on the previous optimal results. Numerical examples demonstrate that the localized severe deviations from the target design are effectively prevented in the optimal design.

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