A new jig-shape optimization method for the high aspect ratio wing

2018 ◽  
Vol 91 (1) ◽  
pp. 124-133
Author(s):  
Zhe Yuan ◽  
Shihui Huo ◽  
Jianting Ren
Keyword(s):  
Aspect Ratio ◽  
Shape Optimization ◽  
High Aspect Ratio ◽  
Optimization Design ◽  
Design Method ◽  
Aircraft Design ◽  
Optimization Method ◽  
Attack Angle ◽  
Structural Deformation ◽  
Content Type

Purpose Computational efficiency is always the major concern in aircraft design. The purpose of this research is to investigate an efficient jig-shape optimization design method. A new jig-shape optimization method is presented in the current study and its application on the high aspect ratio wing is discussed. Design/methodology/approach First, the effects of bending and torsion on aerodynamic distribution were discussed. The effect of bending deformation was equivalent to the change of attack angle through a new equivalent method. The equivalent attack angle showed a linear dependence on the quadratic function of bending. Then, a new jig-shape optimization method taking integrated structural deformation into account was proposed. The method was realized by four substeps: object decomposition, optimization design, inversion and evaluation. Findings After the new jig-shape optimization design, both aerodynamic distribution and structural configuration have satisfactory results. Meanwhile, the method takes both bending and torsion deformation into account. Practical implications The new jig-shape optimization method can be well used for the high aspect ratio wing. Originality/value The new method is an innovation based on the traditional single parameter design method. It is suitable for engineering application.

A Parametric Structure Optimization Method for the Jack-Up Platform

2012 ◽  
Author(s):  
Yan-yun Yu ◽  
Yan Lin ◽  
Zhuo-shang Ji
Keyword(s):  
Shape Optimization ◽  
Optimization Design ◽  
Design Method ◽  
Structure Optimization ◽  
Element Model ◽  
Optimization Method ◽  
Structure Model ◽  
Strength Performance ◽  
High Efficient ◽  
Jack Up

In this paper, A parametric structure optimization method, which is called Parametric Structure Shape Optimization Method (PSSOM), is proposed in order to optimize the structure shape of the jack-up platform. According to the characteristic of the jack-up, an approach to create the Parametric Structure Model (PSM) is proposed. The projections of the main structure onto the horizontal plane are used to create the sketch, which is a 2D drawing driven by dimensions. The 3D modeling technique that based on the sketch and feature modeling is used to create the structure model of the jack-up. A meshing procedure is presented to convert PSM into finite element model automatically together with the boundary conditions and the design loads. After calling the FEM solver, the stress and strain for each structure according to any reasonable dimensions could be calculated, and this is the most important foundation of the structure shape optimization design. An optimization design method based on PSM is proposed for the structure optimization design of the jack-up. The genetic algorithm is used to get the optimum dimensions that have better structure strength performance under the premise of that all the other design requirement are satisfied. PSSOM is proved to be practical and high-efficient by the structure optimization of a 300 ft jack-up platform.

scholarly journals Multiscale, thermomechanical topology optimization of self-supporting cellular structures for porous injection molds

2019 ◽  
Vol 25 (9) ◽  
pp. 1482-1492
Author(s):  
Tong Wu ◽  
Andres Tovar
Keyword(s):  
Topology Optimization ◽  
Mechanical Performance ◽  
Mechanical Load ◽  
Design Method ◽  
Three Dimensional ◽  
Optimization Method ◽  
Cellular Structures ◽  
Injection Mold ◽  
Computationally Efficient ◽  
Content Type

Purpose This paper aims to establish a multiscale topology optimization method for the optimal design of non-periodic, self-supporting cellular structures subjected to thermo-mechanical loads. The result is a hierarchically complex design that is thermally efficient, mechanically stable and suitable for additive manufacturing (AM). Design/methodology/approach The proposed method seeks to maximize thermo-mechanical performance at the macroscale in a conceptual design while obtaining maximum shear modulus for each unit cell at the mesoscale. Then, the macroscale performance is re-estimated, and the mesoscale design is updated until the macroscale performance is satisfied. Findings A two-dimensional Messerschmitt Bolkow Bolhm (MBB) beam withstanding thermo-mechanical load is presented to illustrate the proposed design method. Furthermore, the method is implemented to optimize a three-dimensional injection mold, which is successfully prototyped using 420 stainless steel infiltrated with bronze. Originality/value By developing a computationally efficient and manufacturing friendly inverse homogenization approach, the novel multiscale design could generate porous molds which can save up to 30 per cent material compared to their solid counterpart without decreasing thermo-mechanical performance. Practical implications This study is a useful tool for the designer in molding industries to reduce the cost of the injection mold and take full advantage of AM.

High-Aspect-Ratio Electroplated Structures With 2μm Beamwidth

1999 ◽  
Author(s):  
Xiaobin Li ◽  
Siddharth Kiyawat ◽  
Hector J. De Los Santos ◽  
Chang-Jin “CJ” Kim
Keyword(s):  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Stress Gradient ◽  
Optimization Method ◽  
Nickel Layer ◽  
Driving Voltage ◽  
Aspect Ratios ◽  
Nickel Electroplating ◽  
Electroplating Process ◽  
Micro Structures

Abstract Narrow beamwidth is highly desirable for many micromechanical elements moving parallel to the substrate. A good example is the electrostatically driven flexure structure, whose driving voltage is determined by the width of the beam. This paper presents the process flow and the result of a high-aspect-ratio electroplating process using photoresist (PR) molds. Following a systematic optimization method, PR molds with aspect ratios up to 4.0 were fabricated with a beamwidth of only 2.1μm. Higher aspect ratios, up to 6.8, were achieved using PR double coating technique, with a beamwidth of 2.6μm. Using a Cr/Cu seed layer, nickel electroplating was successfully carried out to translate the PR molds into nickel micro-structures. We observed bend-down of the fully released nickel cantilevers that are over 8μm thick. Further investigation suggested a combined effect of residual stress gradient in the electroplated nickel layer and in-use stiction of the cantilever beams.

Shape Optimization Design of Gravity Buttress of Arch Dam Based on Asynchronous Particle Swarm Optimization Method

2014 ◽  
Vol 662 ◽  
pp. 160-163
Author(s):  
Lei Xu
Keyword(s):  
Particle Swarm Optimization ◽  
Optimization Design ◽  
Design Method ◽  
Particle Swarm ◽  
Optimization Method ◽  
Arch Dam ◽  
Swarm Optimization ◽  
Safety Coefficient ◽  
Parametric Description ◽  
Particle Swarm Optimization Method

The optimization design method was rarely used to design the gravity buttress of arch dam in the past. With this in mind, the parametric description of gravity buttress is given, and the auto-calculation of its exerting loads and the safety coefficient of anti-slide stability are realized subsequently. Then, the optimization design model of gravity buttress and the procedures of optimization design are presented using the asynchronous particle swarm optimization method. Finally, ODGB software, which is short for Optimization Design of Gravity Buttress software, is developed and verified.

Aircraft Configuration Improvement Study from Aerodynamic and Structure Standpoints

2015 ◽  
Vol 798 ◽  
pp. 565-570
Author(s):  
Luciano Magno Fragola Barbosa ◽  
Ricardo Luiz Utsch de Freitas Pinto ◽  
Bernardo Oliveira Hargreaves
Keyword(s):  
Finite Element ◽  
Aspect Ratio ◽  
High Aspect Ratio ◽  
Load Distribution ◽  
Structural Deformation ◽  
Load Factor ◽  
Aircraft Wing ◽  
Induced Drag ◽  
Vertical Displacements ◽  
Lifting Line

In this work improvements on the geometry of a high aspect ratio aircraft wing are studied, in order to reduce the wing in-flight deformation, without changing the drag of the aircraft and without increasing the structural weight. For this, from a reference rectangular wing, one new wing with elliptical planform has been defined; and comparative analyses of loads and structural deformation have been made for the wings considered: the original rectangular wing and the new corresponding elliptical wing. The aerodynamic analysis is based on the lifting line approach. A computer routine is made by the authors based on this approach, to obtain both induced drag values and the load distribution of the two wings, the original one and the corresponding elliptical. Based on the loads, spars for the two wings have been defined, and in order to evaluate the vertical displacements in flight, a finite element routine have been used. The main result of this study is the comparison of the deformation of wings considered, subjected to the same load factor, and for the same aircraft mass. The results obtained are encouraging for further developments using the present methodology.

Improving the Robustness of Adjoint-Based Airfoil Drag Reduction Design

2013 ◽  
Vol 444-445 ◽  
pp. 259-263
Author(s):  
Yan Hong Fan
Keyword(s):  
Drag Reduction ◽  
Optimization Design ◽  
Line Search ◽  
Optimization Problem ◽  
Design Method ◽  
Optimization Method ◽  
Search Method ◽  
Linear Search

The effect of steps in the line search on the consistence of adjoint-based drag reduction of airfoil is investigated in this paper. Constant step adopted in drag reduction design usually gives different optimization results and choice of constant step often depends on designers experience and optimization problem. Bracket method is applied to automatically give the optimal step in performing drag reduction design of airfoils RAE2822 and S73613 and the consistent optimal results are obtained. The results illustrate that the linear search method can automatically find the optimal step, and overcome the restriction on choice of user-defined constant step which is used in the traditional adjoint-based optimization method. That is, it reduces the dependence of step in the drag reduction design, and improves the robustness of the adjoint-based airfoil drag reduction optimization design method.

An Optimization Design Method of Geometric Parameters of Skid Shoe Referring to Subject Weight of Marine Structures

2014 ◽  
Vol 678 ◽  
pp. 325-332
Author(s):  
Feng Yan Yang ◽  
Xiang Zhen Yan ◽  
Zheng Rong Song ◽  
Ming Wang Yang ◽  
Zi Kun Zhao ◽  
...  
Keyword(s):  
Optimization Design ◽  
Design Method ◽  
Plate Thickness ◽  
Optimization Method ◽  
Geometric Parameters ◽  
Frame Structure ◽  
Complex Method ◽  
Optimized Design ◽  
Original Design ◽  
Marine Structures

The optimization design method of geometric parameters of skid shoe which is used to subject weight of marine structures is proposed. Considering skid shoe as steel frame structure, total weight and the bearing capacity of the skid shoe are selected as optimal objectives, and geometric parameters of the skid shoe are taken as design variables. Taking the strength, stiffness, local stability of the skid shoe as the constraint conditions, multi-objectives constraints optimization model of geometric parameters is established, and solved based on complex method. According to research results, a computer program has been developed using VC language. Then geometric optimum parameters of skid shoe in service of CNOOC are analyzed by the program. The results show that optimized design decreases steel volume, steel plate thickness by 28.7%, 18.4%, respectively, compared with original design. The optimization method has a series of advantages, such as simple model, fast calculating speed, high calculation accuracy.

scholarly journals Shape Optimization Design for a Centrifuge Structure with Multi Topological Configurations Based on the B-Spline FCM and GCMMA

2020 ◽  
Vol 10 (2) ◽  
pp. 620
Author(s):  
Xinyao Li ◽  
Liangli He
Keyword(s):  
Shape Optimization ◽  
Optimization Design ◽  
Design Method ◽  
Von Mises Stress ◽  
Design Solution ◽  
Deformation And Failure ◽  
B Spline ◽  
Geotechnical Centrifuge ◽  
Final Configuration ◽  
Deep Groove

The geotechnical centrifuge applied in various geotechnical engineering fields provides physical data for investigating mechanisms of deformation and failure and for validating analytical and numerical methods by simulating and studying the geotechnical problems. The basket, as one of the important components used to place the inspection model of centrifugal test, is designed to withstand complex loads. This paper presents an optimization design method for the basket based on the weighted B-Spline Finite Cell Method (FCM) and the globally-convergent method of moving asymptotes (GCMMA). In order to obtain a superior design solution, four topological configurations, i.e., original single web, porous dual web, open deep groove dual web, and connected closed dual web, are investigated and optimized. The mass is selected as the optimization objective, while key shape parameters and stress are regarded as design variables and the constraint, respectively. By optimization, the final masses of the four configurations are reduced greatly compared with the initial configurations, where the greatest weight loss, in case 4, is 10.6%. This indicates that the weighted B-Spline FCM and GCMMA can be well applied for shape optimization of structure in engineering design. In contrast to the final single web adopted in the traditional basket design in case 1, the final configuration in case 4, i.e., connected closed dual web, has the least mass. The final mass is reduced by 133.38 kg when the centrifuge strength requirement is met. Therefore, the final configuration in case 4, where the maximum von-Mises stress is 398.72MPa and mass is 781.82 kg, is superior to the three other configurations.

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