Shape Optimization Design of Brackets Connecting Girders of an Internal Bulkhead and Pressure Hull Under External Pressure

2017 ◽  
Author(s):  
Chengtao Jiang ◽  
Yuansheng Cheng ◽  
Wei Xiao ◽  
Qijian He ◽  
Shangdi Gao
Keyword(s):  
Shape Optimization ◽  
Optimization Design ◽  
Optimization Problem ◽  
Maximum Stress ◽  
High Stress ◽  
External Pressure ◽  
Coarse Mesh ◽  
Optimal Shapes ◽  
Design Variables ◽  
Hull Structure

In order to decrease the local high stress in the brackets which connect to the horizontal and vertical girders of an internal bulkhead and submersible pressure shell, the mathematical models for the shape optimization of the brackets are proposed. In the study, stress analysis of the pressure hull structure including an internal bulkhead and brackets with coarse mesh is firstly conducted, then the submodeling technique is further employed to analyze the refinement stress distribution of the brackets with refined mesh. The boundary shapes of the brackets are assumed as the design variables while the maximum stress of the bracket is treated as objective function to be minimized in the shape optimization problem. The proposed mathematical model is solved by using analysis code Hyperworks/Optistruct and optimal shapes of the brackets are obtained. Results of the shape optimization show that the optimized bracket types can effectively reduce the level of stress. Therefore, the proposed method can be referred to similar structure designs.

Shape Optimization of Hydraulic Structures: an Example of an Optimum Design of a Fish Passage

10.29007/2k64 ◽  
2018 ◽  
Author(s):  
Pat Prodanovic ◽  
Cedric Goeury ◽  
Fabrice Zaoui ◽  
Riadh Ata ◽  
Jacques Fontaine ◽  
...  
Keyword(s):  
Numerical Model ◽  
Shape Optimization ◽  
Objective Function ◽  
Optimum Design ◽  
Optimization Problem ◽  
A Priori ◽  
Coupled System ◽  
Fish Passage ◽  
Hydraulic Structures ◽  
Design Variables

This paper presents a practical methodology developed for shape optimization studies of hydraulic structures using environmental numerical modelling codes. The methodology starts by defining the optimization problem and identifying relevant problem constraints. Design variables in shape optimization studies are configuration of structures (such as length or spacing of groins, orientation and layout of breakwaters, etc.) whose optimal orientation is not known a priori. The optimization problem is solved numerically by coupling an optimization algorithm to a numerical model. The coupled system is able to define, test and evaluate a multitude of new shapes, which are internally generated and then simulated using a numerical model. The developed methodology is tested using an example of an optimum design of a fish passage, where the design variables are the length and the position of slots. In this paper an objective function is defined where a target is specified and the numerical optimizer is asked to retrieve the target solution. Such a definition of the objective function is used to validate the developed tool chain. This work uses the numerical model TELEMAC- 2Dfrom the TELEMAC-MASCARET suite of numerical solvers for the solution of shallow water equations, coupled with various numerical optimization algorithms available in the literature.

scholarly journals An Innovative Optimization Design Procedure for Mechatronic Systems with a Multi-Criteria Formulation

2021 ◽  
Vol 11 (19) ◽  
pp. 8900
Author(s):  
Cuauhtémoc Morales-Cruz ◽  
Marco Ceccarelli ◽  
Edgar Alfredo Portilla-Flores
Keyword(s):  
Optimization Design ◽  
Optimization Problem ◽  
Heuristic Algorithms ◽  
Design Procedure ◽  
Concurrent Design ◽  
Mechatronic Systems ◽  
Design Variables ◽  
One Step ◽  
Task Oriented ◽  
And Task

This paper presents an innovative Mechatronic Concurrent Design procedure to address multidisciplinary issues in Mechatronics systems that can concurrently include traditional and new aspects. This approach considers multiple criteria and design variables such as mechanical aspects, control issues, and task-oriented features to formulate a concurrent design optimization problem that is solved using but not limited to heuristic algorithms. Furthermore, as an innovation, this procedure address all considered aspects in one step instead of multiple sequential stages. Finally, this work discusses an example referring to Mechatronic Design to show the procedure performed and the results show its capability.

Structural Optimization Design of Steel Tubular Arched Bridge Based on APDL

2014 ◽  
Vol 638-640 ◽  
pp. 1045-1048
Author(s):  
Yong Bin Ma ◽  
Jing Yu Wang ◽  
Bing Dong Gu
Keyword(s):  
Optimization Design ◽  
Maximum Stress ◽  
Structure Optimization ◽  
Steel Tube ◽  
Beam Radius ◽  
State Variables ◽  
Computational Power ◽  
Optimization Analysis ◽  
Design Variables ◽  
Parameterized Model

In order to optimize the structure of steel tube arched bridge, the parameterized model of steel tube arched bridge shall be established on the basis of APDL of ANSYS finite element. based on the huge computational power of ANSYS and the flexibility of APDL parameterization language, choose width of longitudinal beam, radius of arch ring and radius of suspender as design variables, regard maximum deflection and maximum stress as state variables, and take total volume as objective function. Realize structure optimization analysis of steel tubular arched bridge via parameterization computation.

Aerodynamic Optimization Design of Airfoil Based on Directly Manipulated FFD Technique

2013 ◽  
Vol 390 ◽  
pp. 121-128 ◽  
Author(s):  
Jun Qiang Bai ◽  
Song Chen
Keyword(s):  
Shape Optimization ◽  
Drag Reduction ◽  
Optimization Design ◽  
High Order ◽  
Control Points ◽  
Aerodynamic Shape Optimization ◽  
Aerodynamic Optimization ◽  
Aerodynamic Shape ◽  
Design Variables ◽  
Geometrical Constraints

The method of applying direct manipulated FFD (DFFD) technique into aerodynamic shape optimization has been proposed and researched. Due to the disadvantage of the original FFD method within which the geometrical manipulation is not direct and intuitive, the DFFD approach has been developed by solving each displacement of the FFD control points with some specified geometry points movements, so that the deformation of the target geometry could be directly manipulated. Besides, it has been illustrated that by DFFD method a relatively small number of design variables together with high order FFD control frame could be accomplished. The study cases has shown that applying this method in aerodynamic shape optimization of airfoil for drag reduction is of good feasibility and result, and could be coupled with effective geometrical constraints like airfoil thickness.

POD-morphing, an a posteriori grid parametrization method for shape optimization

2010 ◽  
pp. 671-697
Author(s):  
Balaji Raghavan ◽  
Piotr Breitkopf ◽  
Pierre Villon
Keyword(s):  
Shape Optimization ◽  
Air Conditioning ◽  
Optimization Problem ◽  
Compact Set ◽  
Design Domain ◽  
A Posteriori ◽  
Design Variables ◽  
Global Understanding ◽  
Proper Orthogonal ◽  
2D Model

Shape optimization typically involves geometries characterized by several dozen design variables set with no prior knowledge of the design domain topology. A surrogate model can replace the numerous geometry-based design variables with a much more compact set of design variables that have a built-in global understanding of the geometry, thus reducing the size of the optimization problem. In this paper, we present a grid parametrization approach for the design domain geometry based on the method of Proper Orthogonal Decomposition using the method of snapshots, and replace the geometry-based design variables with the smallest possible set of POD coefficients. We demonstrate this method in the well-known problem of designing the section of an air-conditioning duct to maximize the permeability evaluated using CFD with an incompressible 2D model implemented in OpenFOAM.

Multiple Objective Preform Die Shape Optimization Design for Controlling Forging’s Shape and Deforming Force during Forging Process

2011 ◽  
Vol 306-307 ◽  
pp. 1504-1507 ◽  
Author(s):  
Xin Hai Zhao ◽  
Guo Qun Zhao ◽  
Xiao Hui Huang ◽  
Yi Guo Luan
Keyword(s):  
Shape Optimization ◽  
Objective Function ◽  
Optimization Design ◽  
Control Point ◽  
Optimization Procedure ◽  
Multiple Objective ◽  
Forging Process ◽  
Weighted Sum Method ◽  
Design Variables ◽  
The Cost

In order to decrease the cost of the material and energy during the forging process, multiple preform die shape optimization design was carried out in this paper. Based on the FEM, a sensitivity analysis method was used to perform the optimization procedure. The shape of the forging and deforming force of the final forging was used to express the cost of material and energy respectively. Using the weighted sum method, the total objective function was gotton. The coordinates of the control point of the B-spline used to represent the preform die shape was determined as the optimization design variable. The sensitivity equations of the total objective function with respect to the design variables was developed. The multiple objective perform design optimization software was developed by FORTRAN language. And then, the preform die shape of an H-shaped forging process is optimized. The total objective function, sub-objective function, the shape of the preform die and the final forging during the optimization were given. After the optimiztion, a near net shape forging was obtained. At the same time, the deforming force decreased. The optimization results are very satisfactory.

Lightweight Design of Outer Wing Based on Importance Evaluation Factor

2014 ◽  
Vol 532 ◽  
pp. 461-465
Author(s):  
Da Qian Zhang ◽  
Ze Peng Zhu ◽  
Xiao Dong Tan
Keyword(s):  
Optimization Design ◽  
Maximum Stress ◽  
Lightweight Design ◽  
Dynamic Performance ◽  
Maximum Displacement ◽  
Finite Element Software ◽  
State Variable ◽  
Design Variables ◽  
Stress Maximum ◽  
The Mathematical Model

The static and dynamic performance index is constraint condition to establish the mathematical model for optimization design of wing. Basically,the analysis of weighted sensitivity of objective function and state variable imports an importance evaluation factor of wing lightweight design to determine the optimization design variables, then using finite element software , with a optimization design module, to carry out a optimization design. As a result, the analysis of the outer wing shows that the premise of the maximum stress, maximum displacement and low modal frequency are better meet the operating requirements, which the wing weight cumulative reduce to 4.02%. Simultaneously, it proves the efficient and effective of such method.

Application of a Decomposition Technique for Treating a Shape Optimization Problem

1989 ◽  
Author(s):  
M. Bremicker ◽  
H. Eschenauer
Keyword(s):  
Sensitivity Analysis ◽  
Shape Optimization ◽  
Optimization Problem ◽  
Optimization Methods ◽  
Objective Functions ◽  
Shape Optimization Problem ◽  
Boundary State ◽  
Design Variables ◽  
Dimensional Shape ◽  
Suitable Approximation

Abstract The range of application of structural optimization methods can be considerably enlarged by using decomposition techniques. In this paper a novel procedure is introduced to deal with such problems more efficiently. The mechanical structure resp. system is divided into several subsystems splitting up the design variables, objective functions, and constraints accordingly. The boundary state quantities of the subsystems and the global (i.e. subsystem overlapping) functions are approximated by a sensitivity analysis of the entire system using suitable approximation concepts. It is thus possible to optimize the subsystems independently. Variables, objective functions and constraints can be chosen arbitrarily; all coupling information is obtained from the sensitivity analysis by means of global information. The application of this technique is demonstrated by a two-dimensional shape optimization problem.

Buckling Behavior of Optimal Laminated Composite Cylindrical Shells Subjected to Axial Compression and External Pressure

2011 ◽  
Vol 121-126 ◽  
pp. 48-54 ◽  
Author(s):  
Behzad Abdi ◽  
Hamid Mozafari ◽  
Ayob Amran ◽  
Roya Kohandel ◽  
Ali Alibeigloo
Keyword(s):  
Axial Compression ◽  
Optimization Design ◽  
Cylindrical Shells ◽  
Laminated Composite ◽  
Optimization Procedure ◽  
Imperialist Competitive Algorithm ◽  
External Pressure ◽  
Design Variables ◽  
Buckling Behavior ◽  
Composite Cylindrical Shells

In this study, the buckling behavior of optimum laminated composite cylindrical shells subjected to axial compression and external pressure are studied. The cylindrical shells are composed of multi orthotropic layers that the principal axis gets along with the shell axis (x). The number of layers and the fiber orientation of layers are selected as optimization design variables with the aim to find the optimal laminated composite cylindrical shells. The optimization procedure was formulated with the objective of finding the highest buckling pressure. The Genetic Algorithm (GA) and Imperialist Competitive Algorithm (ICA) are two optimization algorithms that are used in this optimization procedure and the results were compared. Also, the effect of materials properties on buckling behavior was analyzed and studied.

scholarly journals Shape Optimization to Reduce Wind Pressure on the Surfaces of a Rectangular Building with Horizontal Limbs

2020 ◽  
Author(s):  
Rajdip Paul ◽  
Sujit Dalui
Keyword(s):  
Shape Optimization ◽  
Incidence Angle ◽  
External Pressure ◽  
Wind Pressure ◽  
Optimal Decision ◽  
Objective Functions ◽  
Building Model ◽  
Multi Objective Genetic Algorithm ◽  
Design Variables ◽  
Decision Variables

The present study consists of shape optimization of a rectangular plan shaped tall building with horizontal limbs under wind attack, which would minimize the wind pressure on all the faces of the building model simultaneously. For the purpose, the external pressure coefficients on different faces of the building (Cpe) are selected as the objective functions. The position of the limbs and the wind incidence angle are taken as design variables. The design of experiment (DOE) is done using random sampling. The values of the objective functions are obtained by using Computational Fluid Dynamics method of simulated wind flow at each design point. The building model has a constant plan area 22500 mm2. The length and velocity scales are taken as 1:300 and 1:5, respectively. The results are used to construct the surrogate models of the objective functions using Response Surface Approximation method. The optimization study is done using the Multi-Objective Genetic Algorithm. The building shapes corresponding to the Pareto optimal decision variables are shown. The function values corresponding to the decision variables are verified by further introducing a CFD study.

Sign in / Sign up

Export Citation Format

Share Document