scholarly journals Applications of Topology Optimization Techniques in Seismic Design of Structure

2012 ◽  
pp. 232-268 ◽  
Author(s):  
Kazem Ghabraie
Keyword(s):  
Topology Optimization ◽  
Seismic Design ◽  
Earthquake Engineering ◽  
Optimization Methods ◽  
Optimization Techniques ◽  
Periodic Loading ◽  
Wide Range ◽  
Numerical Instabilities ◽  
Passive Dampers ◽  
Seismic Design Of Structures

During the last two decades, topology optimization techniques have been successfully applied to a wide range of problems including seismic design of structures. This chapter aims to provide an introduction to the topology optimization methods and a review of the applications of these methods in earthquake engineering. Two well-established topology optimization techniques are introduced. Several problems including eigenfrequency control of structures, compliance minimization under periodic loading, and maximizing energy absorption of passive dampers will be addressed. Numerical instabilities and approaches to overcome them will be discussed. The application of the presented approaches and methods will be illustrated using numerical examples. It will be shown that in seismic design of structures, topology optimization methods can be useful in providing conceptual design for structural systems as well as detailed design of structural members.

Heat Conduction Structural Topology Optimization Based on RAMP

2011 ◽  
Vol 52-54 ◽  
pp. 1692-1697 ◽  
Author(s):  
Jia Chun Li ◽  
Wen Te Tu ◽  
Xu Dong Yang ◽  
Jian Fu ◽  
Yong Tao Wang
Keyword(s):  
Temperature Field ◽  
Topology Optimization ◽  
Heat Conduction ◽  
Optimization Design ◽  
Engineering Application ◽  
Optimization Techniques ◽  
Structural Topology Optimization ◽  
Structural Topology ◽  
Design Problems ◽  
Numerical Instabilities

Based on topology optimization techniques of structural mechanics, an effective method for solving the structural design problems of heat transfer is presented in this paper. The topology optimization model of heat conduction is then constructed and the corresponding Optimization Criteria based on density approach is inferred to solve the optimal heat conduction equation of temperature field. A Filtering technique is employed in density field to eliminate numerical instabilities in the process of topology optimization. Some numerical examples are presented to demonstrate the accuracy and the applicability of the present method, theory and algorithm. This research provides a new idea and an access to the structural topology optimization design of temperature field, and is of good engineering application value.

scholarly journals Optimized Routing Protocols- Enhancement in Mobile Adhoc Network

2021 ◽  
Vol 4 (1) ◽  
pp. 253-260
Author(s):  
Priyanka Thakur ◽  
Sukhpreet Kaur
Keyword(s):  
Routing Protocols ◽  
Performance Metrics ◽  
Optimization Methods ◽  
Optimization Techniques ◽  
Mobile Adhoc Network ◽  
Current Requirement ◽  
Wide Range ◽  
Recent Developments ◽  
Technical Advances ◽  
Adhoc Networks

The recent developments in wireless technology have piqued academics' curiosity. Mobile Adhoc Networks (MANET) is a fast-growing networking architecture used in emergency, disaster, and tactical operations applications. It covers a wide range of applications with some degradation due to its flexible and expandable nature. Because routing is the primary function of wireless networks, routing protocol design is critical in Adhoc networks. Various methods have been used to improve the performance of current routing protocols in different categories. Technical advances in routing protocols have recently been achieved, combined with optimization approaches to improve the overall performance of MANETs routing protocols. This research initially looked at several sorts of routing protocols before going through their variations for energy economy and latency reduction. The previous protocols, which were created utilizing optimization methods, will then illustrate the current requirement. Finally, the review analysis delves into many aspects such as commonly used protocols, optimization techniques, QoS parameters, performance metrics, and future paths.

scholarly journals Review of Guidelines for Seismic Design of Structures with Damping Systems

2018 ◽  
Vol 12 (1) ◽  
pp. 195-204 ◽  
Author(s):  
Sonia E. Ruiz
Keyword(s):  
Seismic Design ◽  
European Standard ◽  
Design Load ◽  
Procedure Selection ◽  
The Usa ◽  
Passive Dampers ◽  
Design Requirements ◽  
Energy Dissipation Devices ◽  
Seismic Design Of Structures ◽  
Damping Systems

Objective: The purpose of this paper is to present an overview of the specifications of three guidelines for the seismic design of structures with passive dampers, to compare their similarities, as well as to discuss topics in which each guideline would be desirable to extend. The guidelines compared here are: a) Minimum Design Load for Buildings and Other Structures (ASCE/SEI 7-16), b) European Standard Anti-seismic Devices (EN 15129), and c) Technical Regulations for Seismic Design, corresponding to Mexico City Building Code (NTCS-17). Methods: The document summarizes and discusses the most significant differences and similarities among the three guidelines for the design of structures with energy dissipation devices. The analysis and discussion are focused on the following sections: 1) Type of Dissipation Devices, 2) General Design Requirements, 3) Procedure Selection, 4) Seismic Design Action, 5) Inspection and 6) Testing of Dissipaters. Conclusion: The paper identifies the gaps in each guideline and gives recommendations about its possible extension. The paper concludes that ASCE/SEI 7-16 presents the procedure selection section with more detail; EN 15129 describes with more detail the Testing section, and NTCS-17, the Inspection section. The paper can be useful for engineers and guideline writers from the USA, Europe, Mexico and other countries that are in process of developing their guidelines for structures with supplementary damping.

Numerical Methods for the Design of Meso-Structures: A Comparative Review

2015 ◽  
Author(s):  
Marcus Yoder ◽  
Zachary Satterfield ◽  
Mohammad Fazelpour ◽  
Joshua D. Summers ◽  
Georges Fadel
Keyword(s):  
Topology Optimization ◽  
Shape Optimization ◽  
Material Properties ◽  
Optimization Methods ◽  
Optimization Techniques ◽  
Future Research ◽  
Structured Materials ◽  
3 Dimensional ◽  
Comparative Review ◽  
Gradient Based

Over the past decade, there has been an increase in the intentional design of meso-structured materials that are optimized to target desired material properties. This paper reviews and critically compares common numerical methodologies and optimization techniques used to design these meso-structures by analyzing the methods themselves and published applications and results. Most of the reviewed research targets mechanical material properties, including effective stiffness and crushing energy absorption. The numerical methodologies reviewed include topology and size/shape optimization methods such as homogenization, Solid Isotropic Material with Penalization, and level sets. The optimization techniques reviewed include genetic algorithms (GAs), particle swarm optimization (PSO), gradient based, and exhaustive search methods. The research reviewed shows notable patterns. The literature reveals a push to apply topology optimization in an ever-growing number of 3-dimensional applications. Additionally, researchers are beginning to apply topology optimization and size/shape optimization to multiphysics problems. The research also shows notable gaps. Although PSOs are comparable evolutionary algorithms to GAs, the use of GAs dominates over PSOs. These patterns and gaps, along with others, are discussed in terms of possible future research in the design of meso-structured materials.

Comparison between NZS 1170.5 seismic design spectra and hysteresis-damped spectra

2017 ◽  
Vol 50 (1) ◽  
pp. 59-70
Author(s):  
Caudillo Aguas
Keyword(s):  
New Zealand ◽  
Seismic Design ◽  
Earthquake Engineering ◽  
Existing Buildings ◽  
Equivalent Viscous Damping ◽  
Design Spectrum ◽  
Design Spectra ◽  
Low Levels ◽  
Displacement Based ◽  
Seismic Design Of Structures

This study aims to provide a comparison and identify the key distinctions between the New Zealand Standard – Earthquake Actions (NZS 1170.5: 2004) seismic design spectra and the hysteresis-damped seismic demand spectra specified by either the New Zealand Society for Earthquake Engineering (NZSEE) “Assessment and Improvement of the Structural Performance of Buildings in Earthquakes” (AISPBE) Guidelines, or the “Displacement-Based Seismic Design of Structures” (DBSDS) textbook by Priestley et al. (2007). The damping provided by the draft document, “The Seismic Assessment of Existing Buildings” (TSAEB), was also briefly discussed. The seismic design spectrum was calculated for various levels of ductility using all three methods and compared against each other. This was performed for structural elastic periods from 0.1 to 4.5 seconds. For a given set of requirements based on the NZS 1170.5 parameters, a representative acceleration-displacement hysteresis loop has been generated. The equivalent viscous damping was then calculated based on the area under this hysteresis using the recommendations of either the AISPBE or through the damping equations based on the DBSDS. The final damped spectra were then compared with each other and against the NZS 1170.5 design spectrum. Results indicate good correlation between the NZS 1170.5 design spectra and the damped design spectra at low levels of ductility but show significant disparities at higher levels of ductility.

Design of a Compliant Micro-Clasp Mechanism for Micromanipulation Tasks

2007 ◽  
Author(s):  
Sandeep Krishnan ◽  
Laxman Saggere
Keyword(s):  
Topology Optimization ◽  
Target Object ◽  
Optimization Techniques ◽  
The Body ◽  
Energy Methods ◽  
Systematic Design ◽  
Micro Scale ◽  
Irregular Shapes ◽  
Wide Range ◽  
Monolithic Structure

This paper introduces the concept of a novel compliant micromanipulator that is capable of manipulating irregularly shaped micro-scale objects by positively clasping the object. The controlled clasp capability of the micromanipulator can be useful to accomplish the manipulation of a wide range of micro-scale objects and biological specimens, especially those with irregular shapes and/or floating in a liquid medium where traditional tweezers or grippers are cumbersome or unsuitable. The monolithic structure of the micromanipulator comprises of two distinct parts: a body and a clasp. The body has a topology that magnifies a single rectilinear input actuation into two larger displacements at the input points to the clasp mechanism. The clasp mechanism comprises of rigid links connected by rotary joints in the form of low-resistance serpentine flexures. The mechanism “clasps” the target object by enveloping the object with a continuous mechanical boundary that eventually closes inwards and “locks” the object within the boundary. The paper presents a systematic design of the compliant micromanipulator and the analytical model governing the behavior of the clasp using topology optimization techniques and energy methods.

Topology optimization techniques for mobile robot path planning

2019 ◽  
Vol 78 ◽  
pp. 528-544 ◽  
Author(s):  
Baotong Li ◽  
Honglei Liu ◽  
Wenjun Su
Keyword(s):  
Topology Optimization ◽  
Path Planning ◽  
Mobile Robot ◽  
Optimization Techniques ◽  
Robot Path Planning ◽  
Robot Path

scholarly journals An efficient approach to reliability-based topology optimization for the structural lightweight design of planar continuum structures

2021 ◽  
Vol 37 ◽  
pp. 270-281
Author(s):  
Fangfang Yin ◽  
Kaifang Dang ◽  
Weimin Yang ◽  
Yumei Ding ◽  
Pengcheng Xie
Keyword(s):  
Topology Optimization ◽  
Lightweight Design ◽  
Integrated Design ◽  
Optimization Methods ◽  
Filter Function ◽  
Continuum Structures ◽  
Performance Indexes ◽  
Reliability Method ◽  
Economic Indexes ◽  
The Impact

Abstract In order to solve the application restrictions of deterministic-based topology optimization methods arising from the omission of uncertainty factors in practice, and to realize the calculation cost control of reliability-based topology optimization. In consideration of the current reliability-based topology optimization methods of continuum structures mainly based on performance indexes model with a power filter function. An efficient probabilistic reliability-based topology optimization model that regards mass and displacement as an objective function and constraint is established based on the first-order reliability method and a modified economic indexes model with a composite exponential filter function in this study. The topology optimization results obtained by different models are discussed in relation to optimal structure and convergence efficiency. Through numerical examples, it can be seen that the optimal layouts obtained by reliability-based models have an increased amount of material and more support structures, which reveals the necessity of considering uncertainty in lightweight design. In addition, the reliability-based modified model not only can obtain lighter optimal structures compared with traditional economic indexes models in most circumstances, but also has a significant advantage in convergence efficiency, with an average increase of 44.59% and 64.76% compared with the other two reliability-based models. Furthermore, the impact of the reliability index on the results is explored, which verifies the validity of the established model. This study provides a theoretical reference for lightweight or innovative feature-integrated design in engineering applications.

scholarly journals A Comprehensive Review of Isogeometric Topology Optimization: Methods, Applications and Prospects

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Jie Gao ◽  
Mi Xiao ◽  
Yan Zhang ◽  
Liang Gao
Keyword(s):  
Topology Optimization ◽  
Computer Aided Design ◽  
Numerical Technique ◽  
Optimization Methods ◽  
Negative Influence ◽  
Comprehensive Overview ◽  
Promising Alternative ◽  
Computer Aided ◽  
Optimal Material ◽  
Material Layout

AbstractTopology Optimization (TO) is a powerful numerical technique to determine the optimal material layout in a design domain, which has accepted considerable developments in recent years. The classic Finite Element Method (FEM) is applied to compute the unknown structural responses in TO. However, several numerical deficiencies of the FEM significantly influence the effectiveness and efficiency of TO. In order to eliminate the negative influence of the FEM on TO, IsoGeometric Analysis (IGA) has become a promising alternative due to its unique feature that the Computer-Aided Design (CAD) model and Computer-Aided Engineering (CAE) model can be unified into a same mathematical model. In the paper, the main intention is to provide a comprehensive overview for the developments of Isogeometric Topology Optimization (ITO) in methods and applications. Finally, some prospects for the developments of ITO in the future are also presented.

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.

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