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Inspired by the seminal paper by Michell (1904), engineers have investigated several tools for the optimization of structural shapes and systems to be employed during the design process. Structural optimization attracts increasing interest in the building industry, especially in the design of high-rise buildings. By selectively distributing the str...
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... During the conceptual design stage, a lot of trial and error or intuition by experts is required to obtain a good structural solution. However, with structural optimization the designer can define the objectives of the design and the constraints to help obtain good and optimal structural solutions [2] . Structural optimization can be categorized into shape optimization, topology optimization and size optimization. ...
Conceptual design in structural engineering entails a large amount of trial and errors or extensive expertise to obtain the most economical and functional design solutions for large engineering projects. In this paper a modern optimization technique called Genetic algorithm, adopting its concept from genetic evolution is used to optimize the shape, size and topology of a plane truss structure with the aim of minimizing the total weight of the truss. A genetic algorithm developed in MATLAB was implemented in this paper to optimize the weight of plane truss structures. The objective function of the optimization problem is subjected to constraints such as stress limits, buckling constraints, tension and compression capacity according to British steel design code BS 5950. The plane trusses which were subject to point loads were tested in the genetic algorithm, the resulting optimized truss structures were then subject to real life loading to determine their feasibility to withstand real life loading. The optimized trusses presented by the algorithm were modelled in a structural analysis and design software called SAP 2000, where they were subjected to dead and live loads. After design the weight saving discovered between the original trusses and the optimized version was between 37 - 47%. The results show that the genetic algorithm implemented in this study is useful in optimizing the weight of a plane truss structure.
... Topology optimization (Bendsoe and Sigmund 2013) is a system-based design approach that has been employed for the design of buildings (Pezeshk et al. 2000;Sarkisian et al. 2009) and other structures. Gradient-based topology optimization techniques (Achtziger and Stolpe, 2007;Stromberg et al. 2011;Asadpoure et al. 2015;Stolpe, 2015) have been used for the design of trusses with continuous and discrete choices considering single objective, such as minimizing the structural mass or compliance, and have been shown to be successful at obtaining global minimum when the problem is convex. ...
The building design community is currently experiencing a shift towards generating more resilient and sustainable designs that are also safe and economic. Integrating these broad, often conflicting, factors into design causes the design process to become more complex, the decisions more difficult, and a need for higher fidelity (and more expensive) modeling efforts to gain insight to resolve these tradeoffs. Set-based design is a promising alternative to traditional point-based design for such complex design problems because many design concepts are generated, refined and carefully eliminated throughout the process thereby maintaining significant freedom in the early stages of design. There is an emerging concept of closely coupling set-based design with model-based simulation to systematically contract the design space through a sequence of modeling efforts in which bounding models are constructed to guarantee the antecedent model only eliminates design alternatives that are dominated when analyzed using a subsequent higher fidelity model. In this paper, the concept of the sequential decision process is explored for the system-level design of seismic-resisting structural frames using nonlinear static analysis. Bounding models are derived for this design problem that are sufficiently general for various types of structural frames. The merit of the novel approach lies in giving designers the ability to search the tradespace exhaustively, arriving at the global minimum with a reduced cost by comparison to a full evaluation using the highest fidelity model while also providing the freedom to retain dominated and non-dominated solutions.
... In the early research pertaining to the 1900s engineer Michell, captured the behavior of the spiral pattern, i.e. spiral forms traverse around a centre and gradually recedes away from it (Figure 4) [11]. This results in most effective cantilever system with minimal amount of raw materials [12]. (Seefig. ...
... 4) This let us know that which switch is required for a particular gene. This displays the minimalism of the biological environment [12]. ...
Biomimicry is a novel approach of developing designs and products or to solve human problems by taking inspiration from nature. It could offer sustainable alternative solutions to conventional and complex design practices. Biomimicry includes mimic of shape, properties, method, principle and processes of the nature. This paper reviews the existing biomimetic inspired civil engineering system and architecture. Bridge design is one of the vital aspects on structures of biomimetics which is derived from the load carrying process of a tree. By mimicking a termite mound, a passive cooling system could be developed. Just like the regeneration process in lizard, a self repairing concrete nullifies the need of repairing process. A few more examples are extracted and are reviewed in this paper. After observing these examples, we can come to very positive point regarding sustainability such as reduction in consumption of materials due to the development of biomimetics inspired optimized tools, less pollution due to the non utilization of mechanical cooling systems in buildings, by applying the passive cooling techniques. Hence incorporating the potentials of the mother earth will lead to the enhancement of structural stability, sustainability and elegance. It will in turn preserve the earth in her best form.
... Topology optimization is gaining momentum in the structural engineering community, with several firms using it to generate concepts for tall buildings (e.g., Baker et al. 4 ; Sarkisian et al. 5 ).Several works have considered using topology optimization to design STM (Kumar 6 , Ali 7 , Biondini et al. 8 16, ). An example from Moen and Guest 11 , given in Fig. 1, is used to illustrate how truss topology optimization can be used to visualize force paths and to develop strut-and-tie models. ...
Structural topology optimization is increasingly being used to remove the guesswork in identifying natural force flow paths for reinforced concrete and prestressed concrete, particularly for complex 3D design domains. Tension and compressive forces that follow the principle stress trajectories, i.e., ties and struts, are automatically identified with topology optimization using a formulation that minimizes strain energy, or equivalently that minimize crack widths. While a useful alternative to trial-and-error process of generating strut-and-tie models (STM), the approach falls short of design objectives as it neglects constructability and rebar detailing, which is often the governing cost. This paper uses a new advancement in topology optimization for addressing constructability issues by considering both material and construction costs. By assigning different construction costs for each tension tie (rebar or prestressing), the placement of steel can be controlled to a large extent by the designer, thus it is capable of generating practical designs that also perform well in service. A hybrid truss-continuum FE model with bilinear orthotropic material properties is used to generate the optimized strut-and-tie models that can be used directly for design and detailing. Results demonstrate that the designer gains the ability to explore tradeoffs between material and labor cost while maintaining reinforcement layouts that ensure structural integrity at service and ultimate limit states.
... Then GA develop a set of points (population), belonging to the domain of the function to be optimized, making sure that the information on each can be transmitted and combined with others. In relation to parameters, defined by a specific domain, the optimization process can be observed in order to search the optimal solution to the objective defined by the user [7][8]. The advantage of these algorithms is needing to know only the function that has to be optimized (objective function), making them more effective than conventional optimization techniques. ...
Designers of modular systems having complex form should consider integrated approaches mostly based on technology, structural mechanics and economy. Due to both the configuration complexity and structural behavior that may be subjected to instability collapse and considerable vibration, the analysis and design of these models may lead to results too complicated to be carried out, limiting the use of new forms. To overcome these obstacles, the use of versatile tools must be applied in both the modeling phase and the analysis phase. The design solutions pursued in the present paper are devoted to the use of parametric software such as Grasshopper, Karamba and Millipide in which, through the modification of parameters, it is possible to vary the construction shape and carry out the structural analysis, taking into account all the above-mentioned components. The present research considers the potential of these tools in the parametric structural optimum design of modular canopies for outdoor installations. The design process is ruled by a development of algorithms for modeling, analysis and optimization of structures, applied to modular service stations. The objective is to model a structure reproducible on a large scale, simple enough to be assembled on site, and inexpensive. It is a canopy designed to organic form in which two parts may be identified: a trunk and an assemblage of radial made up of a series of steel elements connected to each other, supporting a lightweight polycarbonate cover. The dimensional, technological and formal characteristics are provided through a series of structural optimizations controlled with parametric tools.
... The optimizer then works to optimize the distribution of material (steel and load-carrying concrete) throughout the domain. Topology optimization is gaining momentum in the structural engineering community, with several firms using it to generate concepts for tall buildings (e.g., Baker et al. 6 ; Sarkisian et al. 7 ). ...
Strut and tie models (STM) are widely used by designers of reinforced concrete and prestressed concrete structures. Selection of an efficient model, however, becomes a challenging task for complex design domains, such as 3d domains with cutouts. Topology optimization has therefore been promoted as means of automating the development of highly efficient (minimum strain energy) STM. Current drawbacks of such methods are that solutions may complex and fail to properly account for secondary tensile stresses; that is, the case where the major principal stresses are compressive and minor principal stresses are tensile. A hybrid truss-continuum topology optimization scheme was recently developed to overcome these challenges in 2D concrete design. That work is modified and extended herein to three-dimensional domains and mechanics models. The stiffness of the elements are formulated such that truss elements carry only tensile forces and thus represent straight steel rebar, while the continuum elements carry only compressive forces and thus represent the concrete load paths. The latter is achieved using a stress-dependent orthotropic material model. The design goal is then to optimize the STM by minimizing strain energy in the system. The algorithm is demonstrated on several benchmark design examples. Results are shown to produce more efficient STM than traditional designs.
p>Post-tensioned (PT) flat-plate gravity framing systems are highly efficient and reduce embodied carbon, improve construction speed, and reduce seismic mass when compared to conventional reinforced concrete framing systems. While efficiency is especially apparent in multi-span applications with regular orthogonal support arrangement, single-span or irregular support applications are common in high-rise buildings.
A novel approach to determining PT tendon arrangements has been applied to several buildings informed by topology optimization results. Topology optimization is an optimization method which determines optimal load paths in a finite element continuum. By orienting PT tendons along the optimal load paths suggested by topology optimization, several applications have consistently demonstrated reductions in post-tensioned tendon quantities while the amount of mild reinforcement is maintained unchanged. Many of the observed tendon layouts do not follow traditional uniform/banded layouts. Also, the deflection performance is enhanced since tendons are placed in a manner consistent with the load demands.
This new design method has been applied to three buildings and coordinated with construction teams. This presentation will discuss the design procedure which was developed through construction documents as applied to three buildings.</p
