scholarly journals Automatic Position Information of Web-Openings of Building Using Minimized Strain Energy Topology Optimization

2015 ◽  
Vol 2015 ◽  
pp. 1-8
Author(s):  
Dongkyu Lee ◽  
Soomi Shin
Keyword(s):  
Topology Optimization ◽  
Building Design ◽  
Optimization Techniques ◽  
Design Parameters ◽  
Engineering Practice ◽  
Design Domain ◽  
Web Openings ◽  
Position Information ◽  
Design Information ◽  
Density Values

This study presents a new engineering practice and idea that material topology optimization results may be utilized to optimally decide the positions of web-openings of structural members in a building structure. Material topology optimization utilizes element densities as design parameters, that is, nominal constructional material, and then optimal material distributions of densities between voids (0) and solids (1) in a given design domain represent the determination of topology and shape. That means that regions with element density values become occupied by solids in a design domain, while there are only void phases in regions where no density values exist. Therefore, the void regions of topology optimization results may provide design information that decides appropriate depositions of web-opening in structure. Numerical examples demonstrate the efficiency of the present methodological design information using optimization techniques to automatically resolve the building design of proper deposition of web-openings.

Optimum Design of Tractor Clutch PTO Finger by Using Topology and Shape Optimization

2015 ◽  
Author(s):  
O. Dogan ◽  
F. Karpat ◽  
N. Kaya ◽  
C. Yuce ◽  
M. O. Genc ◽  
...  
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Topology Optimization ◽  
Shape Optimization ◽  
Optimization Techniques ◽  
Design Parameters ◽  
Agricultural Activities ◽  
Element Analysis ◽  
Design Life ◽  
Topology And Shape Optimization

Tractors are one of the most important agricultural machinery in the world. They provide agricultural activities in challenging conditions by using various agricultural machineries which are added on them. Therefore, there has been a rising demand for tractor use for agricultural activities. During the power transmission, tractor clutches are exposed to high static and cyclic loading directly. Thus, most of clutch parts fail before completing their design life which is under 106 cycles. Especially, because of the high stress, there are a number of fractures and breakages are observed around the pin area of the finger mechanisms. Due to these reasons, it is necessary to re-design these fingers by using modern optimization techniques and finite element analysis. This paper presents an approach for analysis and re-designs process of tractor clutch PTO finger. Firstly, the original designs of the PTO fingers are analyzed by using finite element analysis. Static structural analyses are applied on these fingers by using ANSYS static structural module. The boundary conditions are determined according to the data from the axial fatigue test bench. Afterwards, the stress-life based fatigue analyses are performed with respect to Goodman criterion. It is seem that the original design of the PTO finger, failed before the design life. Hence, the PTO finger is completely re-designed by using topology and shape optimization methods. Topology optimization is used to find the optimum material distribution of the PTO fingers. Topology optimization is performed in solidThinking Inspire software. The precise dimensions of the PTO fingers are determined by using shape optimization and response surface methodology. Two different design parameters, which are finger thickness and height, are selected for design of experiment and 15 various cases are analyzed. By using DOE method three different equations are obtained which are maximum stresses, mass, and displacement depending on the selected design parameters. These equations are used in the optimization as objective and constraint equations in MATLAB. The results indicate that the proposed models predict the responses adequately within the limits of the parameters being used. The final dimensions of the fingers are determined after shape optimization. The new designs of the PTO fingers are re-analyzed in terms of static and fatigue analysis. The new design of the PTO finger passed the analysis successfully. As a result of the study, the finger mass is increased 7% but it is quite small. Maximum Equivalent Von-Misses stress reduction of 25.3% is achieved. Fatigue durability of the PTO finger is improved 53.2%. The rigidity is improved up to 27.9% compared to the initial design. The optimal results show that the developed method can be used to design a durable, low manufacturing cost and lightweight clutch parts.

Adjoint-Based Sensitivity Analysis for Unsteady Bladerow Interaction Using Space–Time Gradient Method

2017 ◽  
Vol 139 (11) ◽  
Author(s):  
Junsok Yi ◽  
Luigi Capone
Keyword(s):  
Sensitivity Analysis ◽  
Space Time ◽  
Optimization Techniques ◽  
Single Stage ◽  
Time Dependent ◽  
Design Parameters ◽  
Engineering Practice ◽  
Multiple Time ◽  
Blade Design ◽  
Turbomachinery Design

Temporal variation of components' performance is becoming a crucial parameter in turbomachinery design process. The main physical mechanism driving the time-dependent behavior is the unsteady bladerow interaction as stator–rotor relative motion due to rotating frame of reference. However, so far unsteady effects have been ignored in design processes in common engineering practice. In fact, steady approach has been generally employed for computational fluid dynamics (CFD)-based turbomachinery design. Moreover, conventional blade design has been based on single operating point considerations. Taking into account multiple time-dependent phenomena, as the unsteady performance parameters variation, might be beneficial in making a further improvement on component performance. In quantitative terms, first of all it is important to investigate the relative effect of unsteady variation, compared to the standard steady approach, and to create a capability for calculating temporal sensitivity variation, while keeping a reasonable computing cost. This work investigates the unsteady variation of turbomachinery performance on quasi-three-dimensional (3D) geometries: single-stage turbine and single-stage compressor. Steady flow solutions using mixing plane method are compared to the unsteady flow solutions using a direct unsteady calculation, while assessing the introduction of the space–time gradient (STG) method. The results clearly show how the unsteady variation is a non-negligible effect in performance prediction and blade design. Then, a new computational technique to quantify temporal sensitivity variation is introduced, based on the STG method, with an extension to adjoint-based sensitivity analysis. The relation between time and space in multipassage-multirow domain, the fundamental assumption of the STG method, is applied within the adjoint operator formulation, which gives unsteady sensitivity information on a broad range of design parameters, at the cost of a single computation. Finally, the unsteady sensitivities are compared to the ones resulting from steady solution in the two quasi-3D cases. This work introduces a coherent and effective mathematical formulation for accounting deterministic unsteadiness on component design, while reducing computational cost compared to standard unsteady optimization techniques.

Image Matching Assessment of Attainable Topology via Kriging-Interpolated Level-Sets

2014 ◽  
Author(s):  
David Guirguis ◽  
Mohamed Aly ◽  
Karim Hamza ◽  
Hesham Hegazi
Keyword(s):  
Topology Optimization ◽  
Level Set ◽  
Image Matching ◽  
Level Sets ◽  
Optimization Techniques ◽  
Design Domain ◽  
Structural Topology ◽  
Level Set Function ◽  
Design Variables ◽  
Gradient Optimization

Level-set methods are domain classification techniques that are gaining popularity in the recent years for structural topology optimization. Level sets classify a domain into two or more categories (such as material and void) by examining the value of a scalar level-set function (LSF) defined in the entire design domain. In most level-set formulations, a large number of design variables, or degrees of freedom is used to define the LSF, which implicitly defines the structure. The large number of design variables makes non-gradient optimization techniques all but ineffective. Kriging-interpolated level sets (KLS) on the other hand are formulated with an objective to enable non-gradient optimization by defining the design variables as the LSF values at few select locations (knot points) and using a Kriging model to interpolate the LSF in the rest of the design domain. A downside of concern when adopting KLS, is that using too few knot points may limit the capability to represent complex shapes, while using too many knot points may cause difficulty for non-gradient optimization. This paper presents a study of the effect of number and layout of the knot points in KLS on the capability to represent complex topologies in single and multi-component structures. Image matching error metrics are employed to assess the degree of mismatch between target topologies and those best-attainable via KLS. Results are presented in a catalogue-style in order to facilitate appropriate selection of knot-points by designers wishing to apply KLS for topology optimization.

Topology design of slender piezoelectric actuators with repetitive component patterns

2011 ◽  
Vol 22 (18) ◽  
pp. 2161-2172 ◽  
Author(s):  
Xiaoming Wang ◽  
Zhan Kang ◽  
Yiqiang Wang
Keyword(s):  
Topology Optimization ◽  
Actuation Voltage ◽  
Structural Response ◽  
Piezoelectric Actuators ◽  
Optimization Techniques ◽  
Point Of View ◽  
Topology Design ◽  
Programming Approach ◽  
Design Domain ◽  
Mathematical Programming Approach

This article presents a study on topology optimization of planar piezoelectric actuators assembled with repetitive component patterns. Repetitive configuration has the advantage of ease of engineering implementation, especially for relatively slender structures. For realizing this concept in the design of piezoelectric actuators, topology optimization techniques are employed for seeking the optimal layout within the design domain of the structural components. The design objective is to maximize the work delivered by the displacement output port, while constraints are imposed on the actuation energy consumption and the material volume. Both the distributions of the actuation voltage and the topologies of the host layer and the piezoelectric layers are optimized. Power-law penalization functions are used to suppress intermediate values of material densities and actuation voltage. Numerical techniques for a sensitivity analysis of structural response are presented, and the proposed optimization problem is solved with a gradient-based mathematical programming approach. Two numerical examples are given to demonstrate the applicability of the proposed approach. Compared with the method directly treating the whole design domain, this approach is shown to have a better convergence behavior and is able to provide final topologies that are better acceptable from engineering point of view.

Fixture Configuration Design Based on Topology Optimization

1999 ◽  
Author(s):  
Jinling Liu ◽  
S. Jack Hu ◽  
Jingxia Yuan
Keyword(s):  
Topology Optimization ◽  
Optimization Techniques ◽  
Configuration Design ◽  
Design Domain ◽  
Material Distribution ◽  
Configuration Optimization ◽  
New Approach ◽  
Density Method ◽  
Continuous Density ◽  
Fixture Configuration

Abstract This paper proposes a new approach to fixture configuration optimization. This approach is based on the concept of topology optimization of mechanical structures. Unlike existing techniques of fixture configuration optimization, this approach yields the optimal fixture topology by optimizing the fixture material distribution in a design domain, which surrounds the workpiece to be supported. Two methods, discrete density method and continuous density method, are used to optimize fixture topology. Application examples are given to validate these methods and to further illustrate the idea of fixture topology optimization. Compared with existing fixture configuration optimization techniques, the approach presented in this paper optimizes the fixture topology, rather than the number and/or placement of locators.

scholarly journals A Sequential Approach for Aerodynamic Shape Optimization with Topology Optimization of Airfoils

2021 ◽  
Vol 26 (2) ◽  
pp. 34
Author(s):  
Isaac Gibert Martínez ◽  
Frederico Afonso ◽  
Simão Rodrigues ◽  
Fernando Lau
Keyword(s):  
Topology Optimization ◽  
Shape Optimization ◽  
Volume Fraction ◽  
Optimization Techniques ◽  
Free Form ◽  
Aerodynamic Shape Optimization ◽  
Sequential Approach ◽  
Airfoil Surface ◽  
Aerodynamic Shape ◽  
Design Variables

The objective of this work is to study the coupling of two efficient optimization techniques, Aerodynamic Shape Optimization (ASO) and Topology Optimization (TO), in 2D airfoils. To achieve such goal two open-source codes, SU2 and Calculix, are employed for ASO and TO, respectively, using the Sequential Least SQuares Programming (SLSQP) and the Bi-directional Evolutionary Structural Optimization (BESO) algorithms; the latter is well-known for allowing the addition of material in the TO which constitutes, as far as our knowledge, a novelty for this kind of application. These codes are linked by means of a script capable of reading the geometry and pressure distribution obtained from the ASO and defining the boundary conditions to be applied in the TO. The Free-Form Deformation technique is chosen for the definition of the design variables to be used in the ASO, while the densities of the inner elements are defined as design variables of the TO. As a test case, a widely used benchmark transonic airfoil, the RAE2822, is chosen here with an internal geometric constraint to simulate the wing-box of a transonic wing. First, the two optimization procedures are tested separately to gain insight and then are run in a sequential way for two test cases with available experimental data: (i) Mach 0.729 at α=2.31°; and (ii) Mach 0.730 at α=2.79°. In the ASO problem, the lift is fixed and the drag is minimized; while in the TO problem, compliance minimization is set as the objective for a prescribed volume fraction. Improvements in both aerodynamic and structural performance are found, as expected: the ASO reduced the total pressure on the airfoil surface in order to minimize drag, which resulted in lower stress values experienced by the structure.

scholarly journals Comparison of Factorial and Latin Hypercube Sampling Designs for Meta-Models of Building Heating and Cooling Loads

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 512
Author(s):  
Younhee Choi ◽  
Doosam Song ◽  
Sungmin Yoon ◽  
Junemo Koo
Keyword(s):  
Latin Hypercube Sampling ◽  
Building Design ◽  
Gain Coefficient ◽  
Design Parameters ◽  
Latin Hypercube ◽  
Heating And Cooling ◽  
Factor Design ◽  
Heating Loads ◽  
Cooling Loads ◽  
Interest In Research

Interest in research analyzing and predicting energy loads and consumption in the early stages of building design using meta-models has constantly increased in recent years. Generally, it requires many simulated or measured results to build meta-models, which significantly affects their accuracy. In this study, Latin Hypercube Sampling (LHS) is proposed as an alternative to Fractional Factor Design (FFD), since it can improve the accuracy while including the nonlinear effect of design parameters with a smaller size of data. Building energy loads of an office floor with ten design parameters were selected as the meta-models’ objectives, and were developed using the two sampling methods. The accuracy of predicting the heating/cooling loads of the meta-models for alternative floor designs was compared. For the considered ranges of design parameters, window insulation (WDI) and Solar Heat Gain Coefficient (SHGC) were found to have nonlinear characteristics on cooling and heating loads. LHS showed better prediction accuracy compared to FFD, since LHS considers the nonlinear impacts for a given number of treatments. It is always a good idea to use LHS over FFD for a given number of treatments, since the existence of nonlinearity in the relation is not pre-existing information.

Automated simulation techniques for uncovering high-performance bioinspired cellular structures under blast loads

2021 ◽  
pp. 109963622110204
Author(s):  
Abdallah Ghazlan ◽  
Tuan Ngo ◽  
Tay Son Le ◽  
Tu Van Le
Keyword(s):  
Energy Dissipation ◽  
Trabecular Bone ◽  
Reaction Force ◽  
Blast Loading ◽  
Performance Criteria ◽  
Superior Performance ◽  
Cellular Structures ◽  
Design Parameters ◽  
Engineering Practice ◽  
Automated Simulation

Trabecular bone possesses a complex hierarchical structure of plate- and strut-like elements, which is analogous to structural systems encountered in engineering practice. In this work, key structural features of trabecular bone are mimicked to uncover effective energy dissipation mechanisms under blast loading. To this end, several key design parameters were identified to develop a bone-like unit cell. A computer script was then developed to automatically generate bone-like finite element models with many combinations of these design parameters, which were simulated under blast loading. The optimal structure was identified and its performance was benchmarked against traditional engineered cellular structures, including those with hexagonal, re-entrant and square cellular geometries. The bone-like structure showed superior performance over its engineered counterparts using the peak transmitted reaction force and energy dissipation as the key performance criteria.

scholarly journals Analysis of Composite Structures in Curing Process for Shape Deformations and Shear Stress: Basis for Advanced Optimization

2021 ◽  
Vol 5 (2) ◽  
pp. 63
Author(s):  
Niraj Kumbhare ◽  
Reza Moheimani ◽  
Hamid Dalir
Keyword(s):  
Composite Structures ◽  
Latin Hypercube Sampling ◽  
Vital Role ◽  
Optimization Techniques ◽  
Design Parameters ◽  
Curing Process ◽  
Input Variables ◽  
Transient Thermal ◽  
Prototype Design ◽  
Shape Deformations

Identifying residual stresses and the distortions in composite structures during the curing process plays a vital role in coming up with necessary compensations in the dimensions of mold or prototypes and having precise and optimized parts for the manufacturing and assembly of composite structures. This paper presents an investigation into process-induced shape deformations in composite parts and structures, as well as a comparison of the analysis results to finalize design parameters with a minimum of deformation. A Latin hypercube sampling (LHS) method was used to generate the required random points of the input variables. These variables were then executed with the Ansys Composite Cure Simulation (ACCS) tool, which is an advanced tool used to find stress and distortion values using a three-step analysis, including Ansys Composite PrepPost, transient thermal analysis, and static structural analysis. The deformation results were further utilized to find an optimum design to manufacture a complex composite structure with the compensated dimensions. The simulation results of the ACCS tool are expected to be used by common optimization techniques to finalize a prototype design so that it can reduce common manufacturing errors like warpage, spring-in, and distortion.

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