scholarly journals Approximating Bending Stiffness for Structural Optimization of Double-skin Hollowed Car Body Panels

2018 ◽  
Vol 1 (2) ◽  
pp. 25-29
Author(s):  
Yoshiki Ohta
Keyword(s):  
Structural Optimization ◽  
Bending Stiffness ◽  
Design Parameters ◽  
Element Formulation ◽  
Rectangular Plates ◽  
Equivalent Stiffness ◽  
Surface Method ◽  
Equivalent Bending Stiffness ◽  
Double Skin ◽  
Rectangular Element

This paper presents the construction of the approximate equivalent bending stiffness of double-skin hollowed rectangular plates. For this purpose, the equivalent bending stiffness of the plate are expressed first in the quadratic polynomial form with respect to the design parameters for structural optimization by using the Response Surface Method (RSM). Finite element formulation for bending problem of the plate is also formulated by using the ACM rectangular element, and then FE source code is developed by incorporating the equivalent stiffness obtained by the RSM. Finally the numerical results obtained from the present FEA with the equivalent stiffness are compared with the ones by a commercial FE software, ANSYS, and then the applicability of the approximate equivalent stiffness are studied.

scholarly journals Buckling of Corrugated Ring under Uniform External Pressure

Symmetry ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 1250
Author(s):  
Igor I. Andrianov ◽  
Igor V. Andrianov ◽  
Alexander A. Diskovsky ◽  
Eduard V. Ryzhkov
Keyword(s):  
Critical Pressure ◽  
External Pressure ◽  
Homogenization Method ◽  
Bending Stiffness ◽  
Engineering Practice ◽  
Equivalent Stiffness ◽  
Asymptotic Homogenization ◽  
Uniform External Pressure ◽  
Asymptotic Homogenization Method ◽  
Equivalent Bending Stiffness

Stability analysis of a corrugated ring subjected to uniform external pressure is under consideration. Two main approaches to solving this problem are analyzed. The equivalent bending stiffness approach is often used in engineering practice. It is based on some plausible assumptions about the behavior of a structure. Its advantage is the simplicity of the obtained relations; the disadvantage is the difficulty in estimating the area of applicability. In this paper, we developed an asymptotic homogenization method for calculating the critical pressure for a corrugated ring, which made it possible to mathematically substantiate and refine the equivalent bending stiffness approach. To evaluate the results obtained using the equivalent stiffness approach and asymptotic homogenization method, the imperfection method is used. The influence of the corrugation parameters on buckling pressure is analyzed.

ANN-Based Structure Optimization with Fatigue Reliability Constrains

2012 ◽  
Vol 204-208 ◽  
pp. 3128-3131
Author(s):  
Li Rong Sha ◽  
Yue Yang
Keyword(s):  
Structural Optimization ◽  
Objective Function ◽  
Reliability Analysis ◽  
Response Surface ◽  
Minimum Weight ◽  
Structure Optimization ◽  
Fatigue Reliability ◽  
Ann Model ◽  
Surface Method ◽  
The Relationship

The ANN-based optimization for considering fatigue reliability requirements in structural optimization was proposed. The ANN-based response surface method was employed for performing fatigue reliability analysis. The fatigue reliability requirements were considered as constraints while the weight as the objective function, the ANN model was adopted to establish the relationship between the fatigue reliability and geometry dimension of the structure, the optimal results of the structure with a minimum weight was reached.

Structural Optimization of Composite Panel with Lamination Parameters and Equivalent Stiffness Laminate Method

2014 ◽  
Vol 496-500 ◽  
pp. 429-435
Author(s):  
Xiao Ping Zhong ◽  
Peng Jin
Keyword(s):  
Genetic Algorithm ◽  
Structural Optimization ◽  
Composite Structure ◽  
Optimization Procedure ◽  
Optimization Method ◽  
Composite Panel ◽  
Analysis Tool ◽  
Equivalent Stiffness ◽  
Lamination Parameters ◽  
Design Variables

Firstly, a two-level optimization procedure for composite structure is investigated with lamination parameters as design variables and MSC.Nastran as analysis tool. The details using lamination parameters as MSC.Nastran input parameters are presented. Secondly, with a proper equivalent stiffness laminate built to substitute for the lamination parameters, a two-level optimization method based on the equivalent stiffness laminate is proposed. Compared with the lamination parameters-based method, the layer thicknesses of the equivalent stiffness laminate are adopted as continuous design variables at the first level. The corresponding lamination parameters are calculated from the optimal layer thicknesses. At the second level, genetic algorithm (GA) is applied to identify an optimal laminate configuration to target the lamination parameters obtained. The numerical example shows that the proposed method without considering constraints of lamination parameters can obtain better optimal results.

Multi-objective structural optimization of a wind turbine blade using NSGA-II algorithm and FSI

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Ramazan Özkan ◽  
Mustafa Serdar Genç
Keyword(s):  
Structural Optimization ◽  
Wind Turbine ◽  
Turbine Blade ◽  
Wind Turbine Blade ◽  
Design Parameters ◽  
Aerodynamic Optimization ◽  
Nsga Ii ◽  
Content Type ◽  
Multi Objective ◽  
Optimization Study

Purpose Wind turbines are one of the best candidates to solve the problem of increasing energy demand in the world. The aim of this paper is to apply a multi-objective structural optimization study to a Phase II wind turbine blade produced by the National Renewable Energy Laboratory to obtain a more efficient small-scale wind turbine. Design/methodology/approach To solve this structural optimization problem, a new Non-Dominated Sorting Genetic Algorithm (NSGA-II) was performed. In the optimization study, the objective function was on minimization of mass and cost of the blade, and design parameters were composite material type and spar cap layer number. Design constraints were deformation, strain, stress, natural frequency and failure criteria. ANSYS Composite PrepPost (ACP) module was used to model the composite materials of the blade. Moreover, fluid–structure interaction (FSI) model in ANSYS was used to carry out flow and structural analysis on the blade. Findings As a result, a new original blade was designed using the multi-objective structural optimization study which has been adapted for aerodynamic optimization, the NSGA-II algorithm and FSI. The mass of three selected optimized blades using carbon composite decreased as much as 6.6%, 11.9% and 14.3%, respectively, while their costs increased by 23.1%, 29.9% and 38.3%. This multi-objective structural optimization-based study indicates that the composite configuration of the blade could be altered to reach the desired weight and cost for production. Originality/value ACP module is a novel and advanced composite modeling technique. This study is a novel study to present the NSGA-II algorithm, which has been adapted for aerodynamic optimization, together with the FSI. Unlike other studies, complex composite layup, fiber directions and layer orientations were defined by using the ACP module, and the composite blade analyzed both aerodynamic pressure and structural design using ACP and FSI modules together.

Prior and post peaks compressive behavior of concrete-filled double-skin tubular columns with BFRP-punched-in outer steel and BFRP-circular inner steel

2020 ◽  
Vol 23 (13) ◽  
pp. 2911-2927
Author(s):  
Yung William Sasy Chan ◽  
Zhi Zhou ◽  
Zhenzhen Wang ◽  
Jinping Ou
Keyword(s):  
Load Capacity ◽  
High Energy ◽  
Fiber Reinforced Polymer ◽  
Confined Concrete ◽  
Peak Performance ◽  
Design Parameters ◽  
Fiber Reinforced ◽  
Tubular Columns ◽  
Reinforced Polymer ◽  
Double Skin

Fiber-reinforced polymer composites have been widely used to design fiber-reinforced polymer–based confined concrete columns with potential benefits. However, it is critical to design a column with sufficient post-peak performance that can prevent its collapse at the rupture of the fiber-reinforced polymer tube. This article presents the experimental results on the prior and post peaks behavior of concrete-filled double-skin tubular columns with basalt fiber-reinforced polymer (BFRP)–punched-in outer steel and BFRP-circular inner steel (BFST-DSTCs). Twenty-two specimens were tested under axial compression to investigate the effects of design parameters on the behavior of the BFST-DSTC. The outcomes reveal that the BFST-DSTC exhibits the best performance in terms of load capacity, confinement ratio, failure and damage mechanisms, and ductility in prior and post peaks. The inner fiber-reinforced polymer jacket delays the buckling of the inner tube. The punched-in patterns of the outer steel improve the confinement effectiveness of the fiber-reinforced polymer jacket. The BFST-DSTC displays a good post-peak performance with high-energy dissipation capacity that prevents the concerned structure from collapse after the fiber-reinforced polymer jacket rupture. Finally, a new confinement model is proposed to predict the ultimate point of the confined concrete.

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