Параметрическая оптимизация анизогридных оболочек нерегулярной структуры

Chapter 1 Introduction of swarm intelligent algorithms.- Chapter 2 Application of particle swarm optimization algorithm to engineering structures.- Chapter 3 Optimum design of structures with heuristic particle swarm optimization algorithm .-Chapter 4 Optimum design of structures with group search optimizer algorithm .-Chapter 5 Improvements and applications of group search optimizer in structural optimal design .-Chapter 6 Optimum design of structures with quick group search optimization algorithm .-Chapter 7 Group search optimizer and its applications on multi-objective structural optimal design .-Chapter 8 Prospecting swarm intelligent algorithms.

It is well understood that the dominant approach in the seismic design of structures is to reduce the initial cost while meeting the required safety level, as dictated by compliance codes. Nevertheless, this approach often overlooks the long-term costs that are incurred over the lifetime of the structures. A comprehensive approach is thus required for a design based on life cycle cost (LCC), where both initial and long-term costs are considered. While LCC-based design has been employed on regular structures, irregular structures have not received adequate attention. This research aims to highlight the impact of irregularity on the LCC optimization of tall structures. To do this, a bi-objective heuristic optimization framework is developed to balance the initial and long-term costs. The framework is used to analyze six steel regular and setback irregular structures with 7, 10, and 13 stories. The structures are all designed to meet the life safety performance level. The findings show that the irregular structures reveal a higher sensitivity to variations in initial costs compared to regular structures, which are mainly buildings above 13 stories. We also show that reducing the LCCs of irregular structures requires a higher increase in the initial cost compared to regular structures; for example, in the regular and irregular 13-story structures, a 17% increase in the initial cost resulted in approximately 48% and 40% reductions in the LCCs, respectively. Overall, our results confirm that the long-term costs of irregular structures are more than those of regular ones; this is an important finding that should be considered for the seismic design of tall irregular structures.

DSLC-FOA : Improved fruit fly optimization algorithm for application to structural engineering design optimization problems

The growing urgency for sustainable construction practices has necessitated a reevaluation of traditional design approaches in favor of more environmentally responsible methodologies. This paper presents a comparative analysis between optimal and adequate structural design within the context of sustainable construction. Focusing on two case studies—a cutting-edge, sustainably designed commercial building (the Bullitt Center) and a conventional mid-rise residential building in Chicago—the research explores how different design philosophies impact material efficiency, environmental footprint, economic performance, and occupant satisfaction.Through detailed life cycle assessments (LCA) and life cycle energy analyses (LCEA), the study quantifies the advantages of optimal design, which integrates advanced materials, renewable energy systems, and water conservation technologies. The findings demonstrate that while optimal design requires a higher initial investment, it significantly reduces long-term operational costs and environmental impact, achieving a net-zero energy status and greatly improving occupant well-being. In contrast, the conventional building, which adheres to standard design practices, exhibits higher embodied energy, greater environmental degradation, and lower occupant satisfaction.The paper concludes that optimal structural design is not only more sustainable but also economically viable over the building's life span. It emphasizes the importance of integrating sustainability from the earliest stages of design to achieve meaningful environmental and economic benefits. The study calls for the adoption of policy incentives and advanced modeling tools to facilitate the widespread implementation of optimal design principles in the construction industry. Keywords: Sustainable Construction, Optimal Structural Design, Adequate Design, Building Performance, Embodied Energy, Environmental Impact, Economic Viability, Material Efficiency

An improved optimization algorithm based on a homogenization method will be presented to perform simultaneously the optimal shape and topology design of plate and shell structures for eigenvalue optimization problems. This algorithm can improve the dynamic behavior of structures through the optimal layout design of structures. This design problem is relaxed by using a perforated structure in order to generate the topology as well as the shape of structures. By homogenization of the perforated structure, the formulation of this relaxed problem can be rigorously obtained. Furthermore, a multi-purpose, multimodal objective function is used to deal with a variety of eigenvalue optimization problems. These optimization problems are solved using an improved optimality criterion method. Three practical examples are solved to substantiate the proposed algorithm and objectives.

Reliability-based optimum distribution of seismic energy dissipation devices in fuzzy structural systems using meta-models

This paper includes description of reliability based design optimization of elasto-plastic skeletal structures under multi-parameter static loading. Presented approach is based on the assumption that the complementary strain energy of the residual forces is considered as an overall measure of the plastic performance for plastic shakedown analysis and optimal design of the structure, and this measure is an uncertain quantity responsible for resistance of the structure by assuming Gaussian distribution. The problems yield to nonlinear mathematical programming which are solved by the use of bi-level sequential quadratic algorithm. Simple portal frames are optimized to illustrate the proposed approaches.

Stochastic optimization methods have been widely employed to find solutions to structural design optimization problems in the past two decades, especially for truss structures. The primary aim of this study is to introduce a design optimization method combining an augmented Lagrangian function and teaching–learning-based optimization for truss and nontruss structural design optimization. The augmented Lagrangian function serves as a constraint-handling tool in the proposed method and converts a constrained optimization problem into an unconstrained one. On the other hand, teaching–learning-based optimization is employed to resolve the transformed, unconstrained optimization problems. Since the proper values of the Lagrangian multipliers and penalty factors are unknown in advance, the proposed method is implemented in an iterative way to avoid the issue of selecting them, i.e. the Lagrangian multipliers and penalty factors are automatically updated according to the violation level of all constraints. To examine the performance of the proposed method, it is applied on a group of benchmark truss optimization problems and a group of nontruss optimization problems of aircraft wing structures. The computational results obtained by the proposed method are compared to the results produced by both other version of teaching–learning-based optimization and stochastic optimization methods.

The optimal and smart design of nonlinear building structures with and without passive dampers subjected to earthquake loading is of great concern in the structural design of building structures. The research started around 1980 and many investigations have been conducted. A comprehensive review on this subject is made in this article. After the description of essential features of the optimal design problem of nonlinear building structures under earthquake ground motions, analysis types of optimization problems are explained and the significance of the dynamic pushover analysis is discussed from the viewpoint of analysis of limit states under earthquake ground motions of magnitude larger than the code-specified level. Then, the categorization by the response of frames and dampers was made. In this categorization, several subjects are discussed first: 1) Optimal design of bare nonlinear building frames under seismic loading, 2) Optimal design of nonlinear dampers for elastic building frames under seismic loading, 3) Optimal design of linear dampers for nonlinear building frames under seismic loading, 4) Optimal design of nonlinear building frames with specified nonlinear dampers under seismic loading, 5) Optimal design of nonlinear dampers for specified nonlinear building frames under seismic loading, 6) Simultaneous optimization of elastic-plastic building structures and passive dampers. Finally, the classification of researches in view of solution strategies is conducted for providing another viewpoint.

Space satellite design generally involves multidisciplinary collaboration processes, such as structural, heat transfer and electrical design processes, aimed at fulfilling various functional requirements that are subject to stringent weight and spatial limitations. This paper discusses a practical application of a systematic design optimization approach to the design of a small satellite called “Micro-LabSat,” in order to obtain optimal solutions that take into account such multidisciplinary design factors. The satellite design problem has two sub design problems, a component arrangement problem and a structural design problem, and the features of these two problems are entirely different since the component arrangement problem involves discrete design variables such as the positions of the components, while the structural design problem has continuous design variables such as the dimensions of the parts. Therefore, a bi-level optimization procedure is applied. First, two sublevel optimization problems for the sub design problems are solved. A two-phase optimization procedure that uses genetic algorithms and SQP (Sequential Quadratic Programming) is applied to the component arrangement problem, and SQP is applied to the structural optimization. Then, the satellite-level optimization problem that considers all factors, including both the component arrangement and structural problems, is solved using the sublevel optimal solutions as initial points for optimization. The bi-level optimization scheme presented here provides an efficient search procedure, and offers optimal solutions in short calculation times.

Recently, much effort has been expended in establishing the well‐posedness of optimal structural design problems. Experience indicates, however, that awareness of the non‐existence of a solution may also be beneficial and can eliminate time wasted in searching for non‐existing numerical or analytical optima. Two standard approaches to non‐existence proofs are presented: the construction of suitable sequences and the use of necessary conditions — both within the context of contradiction proofs. The methods are illustrated with examples from optimal structural design ranging from the minimum weight design of an axially loaded rod to that of axisymmetrically loaded shells of revolution. It is shown that the causes of non‐existence can be the choice of function space, boundary conditions, and a discontinuous dependence on parameters, among others. Some possible guidelines for a successful formulation of well‐posedness in structural design are included.

Design of optimum structures

Optimal structural design of stiffened plate structure with multi order modal frequencies objective is discussed. It is a structural reverse design problem for the first several order modal frequencies to reach a set of given value. A new method based on bi-directional evolutionary structural optimization (BESO) and size optimization is presented. To solve the porous and irregular shape problem in the optimized structure, a regular shaped grid-like frame structure optimization model is established. The bars in the frame structure are regarded as basic unites of structure modification. The bars’ sensitivity is discussed, and applied to optimization process based on frequency sensitivity. The structural optimal design process can be described as follows: the frequencies are used as the target, the volume is considered as constraint, adjacent sensitivity redistribution method is adopted to suppress numerical instability. Then size optimization method is adopted to conduct detailed design. Finally this method is applied to a stiffened plate structure. Results show that the proposed approach is feasible to achieve given multi order modal frequencies. The optimized structure consists of regular bars, so a clear structure is obtained.

The rapid computation of random eigenvalue problems of uncertain structures is the key point in structural dynamics, and it is prerequisite to the efficient dynamic analysis and optimal design of structures. In this paper, by combining finite element-transfer matrix method (FE-TMM) with perturbation method, a new method named as perturbation FE-TMM is presented for random eigenvalue problems of uncertain structures. By using the proposed method, the rapid computation of random eigenvalue problems of uncertain structures with complicated shapes and boundaries can be achieved, and the repeated eignvalues and characteristic vectors can be solved conveniently. Compared with stochastic finite element method, this method has the low memory requirement, high computational efficiency and high computational stability. It has more advantages for dynamic design of uncertain structures. Formulations as well as some numerical examples are given to validate the method.

A holistic approach to risk-based decision on inspection and design of fatigue-sensitive structures