OPTIMUM DESIGN OF REINFORCED CONCRETE FOUNDATIONS

2020 ◽  
Vol 14 ◽  
Author(s):  
Osama Bedair
Keyword(s):  
Reinforced Concrete ◽  
Cost Function ◽  
Numerical Procedure ◽  
Optimization Procedure ◽  
Analytical Models ◽  
Design Parameters ◽  
Foundation Design ◽  
Programming Technique ◽  
Concrete Foundation ◽  
The Cost

Background: Optimization of reinforced concrete foundation is a challenging problem in practice due to interaction between the design variables and constraints. Classical design methods may overestimate the size of the foundation, thus leading to excessive cost. By using current advances in computer technologies and numerical optimization procedures, it is possible to find the optimum combinations of foundations design parameters that minimize the cost. Objectives: The paper presents a numerical strategy to optimize the design of reinforced concrete foundation. Method: The cost function is first derived in terms of the foundation design parameters. Mathematical programming technique is utilized to minimize the cost function. Design constraints are used against soil bearing capacity, concrete shear strength, flexural strength and column bearing. Simplified analytical models are developed to idealize the soil stress distribution. The numerical procedure is then automated in a computer Program “OSFD” to perform sensitivity analysis and provide guidelines that can be utilized in practice. Results: Design examples are provided to illustrate efficiency of the optimization procedure. Results are compared with exiting conventional design procedures, commercial softwares and design handbooks available in practice. Conclusions: The described procedure is very cost effective that can be effectively utilized by practicing Engineers in the industry to optimize the design of reinforced concrete foundation.

scholarly journals Evaluation of the Cost-Optimal Method Applied to Existing Schools Considering PV System Optimization

Energies ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 611
Author(s):  
Cecilia Ciacci ◽  
Neri Banti ◽  
Vincenzo Di Naso ◽  
Frida Bazzocchi
Keyword(s):  
Optimization Procedure ◽  
Cost Effective ◽  
Heating System ◽  
System Optimization ◽  
Cold Climate ◽  
Design Parameters ◽  
Design Environment ◽  
Pv System ◽  
Optimal Method ◽  
The Cost

In Italy in 2020, only 15.5% of school building heritage was retrofitted from an energy and environmental point of view. In this paper, the cost-optimal method was applied to two different school buildings belonging to the same Italian cold climate zone but characterized by different structural and technological solutions. The research aims at defining the cost-effective redevelopment solution among several ones proposed to apply to this building type. At the same time, this paper provides a critical analysis of the methodology applied, highlighting deficiencies related to a not proper evaluation of environmentally friendly retrofitting measures. In a cost-effective context, the main results show that the intervention on the heating system is more convenient than the retrofitting of the envelope. The energy saving is equal to about 35% for both considered schools. Among the different proposed requalification configurations, the adoption of PV (photovoltaic) electric generation is included. In this regard, an optimization procedure was implemented in a generative design environment to maximize energy production with reference to different design parameters. As a result, a solution with south oriented PV modules with a tilt angle of 42° and arranged in 0.7 m spaced rows proved to be the most effective.

Design and Optimization of Stamping Process to Improve Manufacturing Feasibility

2000 ◽  
Author(s):  
H. Naceur ◽  
Y. Q. Guo ◽  
J. L. Batoz
Keyword(s):  
Numerical Procedure ◽  
Optimization Procedure ◽  
Forming Limit Diagram ◽  
Forming Limit ◽  
Programming Technique ◽  
Design And Optimization ◽  
Stamping Process ◽  
Design Variables ◽  
Risk Of Rupture ◽  
Analytical Sensitivities

Abstract In this paper, we present a numerical procedure combining a finite element inverse approach (I.A.) [10, 14–18] for the simplified analysis of the stamping process with a mathematical programming technique (BFGS method) to optimize some process parameters. Our objective is to optimize the quality of the final workpiece, by minimizing the risk of rupture and wrinkles. The design variables of the present problem are the drawbead restraining forces in relation with the Forming Limit Diagram (FLD). The optimization procedure associated to the analytical sensitivities analysis technique based on the adjoint method is applied for the square cup of Numisheet’93 and the Twingo dashpot cup proposed by RENAULT [32]. The satisfactory results demonstrate the usefulness of this automatic optimization procedure in the preliminary design of deep-drawing process.

scholarly journals Analytical Models for Optimal Design of a Trapezoidal Composite Channel Cross-Section

2021 ◽  
Vol 31 (1) ◽  
pp. 118-138
Author(s):  
Somayyeh Pourbakhshian ◽  
Majid Pouraminian
Keyword(s):  
Optimal Design ◽  
Cost Function ◽  
Objective Function ◽  
Cross Section ◽  
Analytical Models ◽  
Channel Cross Section ◽  
Roughness Coefficient ◽  
Composite Channel ◽  
Design Variables ◽  
The Cost

Abstract In this paper, several analytical models are presented for the optimal design of a trapezoidal composite channel cross-section. The objective function is the cost function per unit length of the channel, which includes the excavation and lining costs. To define the system, design variables including channel depth, channel width, side slopes, freeboard, and roughness coefficients were used. The constraints include Manning’s equation, flow velocity, Froude number, and water surface width. The Simultaneous Perturbation Stochastic Approximation (SPSA) algorithm was used to solve the optimization problem. The results are presented in three parts; in the first part, the optimal values of the design variables and the objective function are presented in different discharges. In the second part, the relationship between cost and design variables in different discharges is presented in the form of conceptual and analytical models and mathematical functions. Finally, in the third part, the changes in the design variables and cost function are presented as a graph based on the discharge variations. Results indicate that the cost increases with increasing water depth, left side slope, equivalent roughness coefficient, and freeboard.

scholarly journals Two-Stage Optimization Method for the Bearing Layout of Isolated Structure

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
Yu Dang ◽  
GenXiong Zhao ◽  
HongTu Tian ◽  
Guobao Li
Keyword(s):  
Optimization Technique ◽  
Optimal Solution ◽  
Nonlinear Behavior ◽  
Optimization Procedure ◽  
Optimization Method ◽  
Design Parameters ◽  
Two Stage ◽  
Factors Affecting ◽  
Lead Rubber Bearing ◽  
The Cost

Design of seismic isolated building is often a highly iterative and tedious process due to the nonlinear behavior of the system, a large range of design parameters, and uncertainty of ground motions. It is needed to consider a comprehensive optimization procedure in the design of isolated buildings with optimized performances. This can be accomplished by applying a rigorous optimization technique. However, due to many factors affecting the performance of isolated buildings, possible solutions are abundant, and the optimal solution is difficult to obtain. In order to simplify the optimization process, an isolated building is always modeled as a shear-type structure supported on the isolated layer, and the optimal results are the parameters of the isolated layer which could not be used as a practical design of the isolated structure. A two-stage optimization method for designing isolated buildings as a practical and efficient guide is developed. In the first stage, a 3D isolated building model is adopted that takes into account of nonlinear behavior in building and isolation devices. The isolation devices are simplified as a kind of lead-rubber bearing. The genetic algorithm is used to find the optimal parameters of the isolated layer. In the second stage, the location parameters of isolation bearing layout are optimized. Moreover, the cost of the isolation bearing layout should be as low as possible. An integer programming method is adopted to optimize the number of each type of isolator. Considering vertical bearing capacity of isolators and the minimum eccentricity ratio of the isolated layer, the optimal bearing layout of the isolated building can be obtained. The proposed method is demonstrated in a typical isolated building in China. The optimum bearing layout of the isolated building effectively suppresses the structural seismic responses, but the cost of the isolated layer might slightly increase.

scholarly journals Field Monitoring and Numerical Analysis of the Reinforced Concrete Foundation of a Large-Scale Wind Turbine

2021 ◽  
Vol 2021 ◽  
pp. 1-14
Author(s):  
Yanming Zhou ◽  
Xinxi Liu ◽  
Zongwei Deng ◽  
Qian-Feng Gao
Keyword(s):  
Reinforced Concrete ◽  
Wind Turbine ◽  
Large Scale ◽  
Dynamic Contact ◽  
Shallow Foundation ◽  
Foundation Design ◽  
Onshore Wind ◽  
Concrete Foundation ◽  
Operation Phase ◽  
Contact Pressures

The objective of this study is to examine the performance of the shallow reinforced concrete foundation of a large-scale wind turbine under the influence of environmental loads. A 2 MW horizontal-axis onshore wind turbine supported by a shallow concrete foundation was considered. The foundation stresses, foundation settlements, and static and dynamic contact pressures at various positions of the shallow foundation were monitored from the construction phase to the operation phase in the field. Numerical simulations were also performed to further analyze the behavior of the wind turbine foundation in different cases. The results demonstrate that the responses of the reinforced concrete foundation, i.e., foundation stresses, contact pressures, and foundation settlements, were variables closely related to the wind direction and wind speed. The distribution of foundation stresses suggested that a reasonable design of steel reinforcement cages around the foundation steel ring is important. The dynamic contact pressure of the foundation could reach 5 kPa, so the influence of dynamic wind loads on the foundation response could not be always neglected, particularly for the foundations seated on weak soils. The foundation settlement during the operation phase could be characterized by the logistic model, but its distribution was uneven due to the presence of eccentric upper weight and wind load. The findings would provide guidance for the foundation design of onshore wind turbines in hilly areas.

Feasibility, efficiency and transportability of short-horizon optimal mixing protocols

2008 ◽  
Vol 597 ◽  
pp. 199-231 ◽  
Author(s):  
LUCA CORTELEZZI ◽  
ALESSANDRA ADROVER ◽  
MASSIMILIANO GIONA
Keyword(s):  
Cost Function ◽  
Time Horizon ◽  
Optimization Procedure ◽  
Nonlinear Flow ◽  
Mixing Efficiency ◽  
Advection Diffusion ◽  
Optimal Protocol ◽  
The Cost ◽  
Short Time ◽  
Optimal Mixing

We consider, as a case study, the optimization of mixing protocols for a two-dimensional, piecewise steady, nonlinear flow, the sine flow, for both the advective–diffusive and purely advective cases. We use the mix-norm as the cost function to be minimized by the optimization procedure. We show that the cost function possesses a complex structure of local minima of nearly the same values and, consequently, that the problem possesses a large number of sub-optimal protocols with nearly the same mixing efficiency as the optimal protocol. We present a computationally efficient optimization procedure able to find a sub-optimal protocol through a sequence of short-time-horizon optimizations. We show that short-time-horizon optimal mixing protocols, although sub-optimal, are both feasible and efficient at mixing flows with and without diffusion. We also show that these optimized protocols can be derived, at lower computational cost, for purely advective flows and successfully transported to advective–diffusive flows with small molecular diffusivity. We characterize our results by discussing the asymptotic properties of the optimized protocols both in the pure advection and in the advection–diffusion cases. In particular, we quantify the mixing efficiency of the optimized protocols using the Lyapunov exponents and Poincaré sections for the pure advection case, and the eigenvalue–eigenfunction spectrum for the advection–diffusion case. Our results indicate that the optimization over very short-time horizons could in principle be used as an on-line procedure for enhancing mixing in laboratory experiments, and in future engineering applications.

Differential Evolution Algorithm In Models Of Technical Optimization

2021 ◽  
Author(s):  
Roman Knobloch ◽  
Jaroslav Mlynek
Keyword(s):  
Differential Evolution ◽  
Cost Function ◽  
Optimization Algorithms ◽  
Differential Evolution Algorithm ◽  
Gradient Methods ◽  
Optimization Procedure ◽  
Acceptable Solution ◽  
Optimization Task ◽  
Evolution Algorithm ◽  
The Cost

At present, evolutionary optimization algorithms are increasingly used in the development of new technological processes. Evolutionary algorithms often allow the optimization procedure to be performed even in cases where classical optimization algorithms fail (e.g. gradient methods) and where an acceptable solution is sufficient to solve the optimization task. The article focuses on possibilities of using a differential evolution algorithm in the optimization process. This algorithm is often referred to in the literature as a global optimization procedure. However, we show by means of a practical example that the convergence of the classic differential algorithm to the global extreme is not generally assured and is largely dependent on the specific cost function. To remove this weakness, we designed a modified version of the differential evolution algorithm. The improved version, named the modified differential evolution algorithm, is described in the article. It is possible to prove asymptotic convergence to the global minimum of the cost function for the modified version of the algorithm.

L-shaped reinforced concrete retaining wall design: cost and sizing optimization

2020 ◽  
Vol 6 (3) ◽  
pp. 140
Author(s):  
Aylin Ece Kayabekir ◽  
Zülal Akbay Arama ◽  
Gebrail Bekdaş ◽  
İlknur Dalyan
Keyword(s):  
Reinforced Concrete ◽  
Retaining Wall ◽  
Cost Effective ◽  
Optimization Methods ◽  
Design Parameters ◽  
External Loading ◽  
Engineering Structures ◽  
Optimal Dimension ◽  
Wall Foundation ◽  
The Cost

In the context of this study, the design of L-shaped reinforced concrete retaining walls have been scrutinized parametrically depending on the simultaneous analysis of cost and sizing with the use of a recent optimization algorithm. The differences and restrictions of L-shaped reinforced concrete retaining wall design than classical T-shaped walls have been also discussed. The foundation width and the thickness of the wall required for a safe design has been also investigated according to the change of excavation depth, the type of soil dominating field and the external loading conditions. The observed results from optimization analyses shows that the variation of the shear strength angle is the most significant soil geotechnical parameter for supplying an envisaged safe design against sliding, overturning and adequate bearing capacity. Concurrently, the excavation depth is the most important factor that is forming the necessity of the construction of the retaining structure and optimal dimension evaluation. It is also proved that the wall foundation width is the most effected dimension of the retaining structures by the change of design parameters and the cost difference is directly influenced by the change of sizing. A cost-effective wall design can be performed with the use of proposed optimization analysis is capable in a shorter time than the traditional methods. Eventually, it has shown that such optimization methods may be useful to find the optimal design requirements for geotechnical engineering structures.

EXPERIMENTAL STUDIES OF REINFORCED CONCRETE STRUCTURES WITH CROSS-SHAPED SPATIAL CRACK UNDER TORSION WITH BENDING

2020 ◽  
Vol 92 (6) ◽  
pp. 13-25
Author(s):  
Vl.I. KOLCHUNOV ◽  
◽  
A.I. DEMYANOV ◽  
M.M. MIHAILOV ◽  
◽  
...  
Keyword(s):  
Reinforced Concrete ◽  
Experimental Determination ◽  
Calculation Method ◽  
Experimental Studies ◽  
Concrete Structures ◽  
Design Parameters ◽  
Reinforced Concrete Structures ◽  
Experimental Scheme

The article offers a method and program for experimental studies of reinforced concrete structures with cross-shaped spatial crack under torsion with bending, the main purpose of which is to check the design assumptions and experimental determination of the design parameters of the proposed calculation method. The conducted experimental studies provide an opportunity to test the proposed calculation apparatus and clarify the regularities for determining deflections, angles of rotation of extreme sections, and stresses in the compressed zone of concrete. For analysis, the article presents a typical experimental scheme for the formation and development of cracks in the form of a sweep, as well as characteristic graphs of the dependence of the angles of rotation of end sections.

scholarly journals Numerical Modelling of Reinforced Concrete Slender Walls Subjected to Coupled Axial Tension–Flexure

2021 ◽  
Vol 15 (1) ◽  
Author(s):  
Xiaowei Cheng ◽  
Haoyou Zhang
Keyword(s):  
Reinforced Concrete ◽  
Plastic Hinge ◽  
Element Model ◽  
Lateral Loading ◽  
Design Parameters ◽  
Seismic Behaviour ◽  
High Rise ◽  
Ultimate Deformation ◽  
Axial Tension ◽  
Plastic Hinge Length

AbstractUnder strong earthquakes, reinforced concrete (RC) walls in high-rise buildings, particularly in wall piers that form part of a coupled or core wall system, may experience coupled axial tension–flexure loading. In this study, a detailed finite element model was developed in VecTor2 to provide an effective tool for the further investigation of the seismic behaviour of RC walls subjected to axial tension and cyclic lateral loading. The model was verified using experimental data from recent RC wall tests under axial tension and cyclic lateral loading, and results showed that the model can accurately capture the overall response of RC walls. Additional analyses were conducted using the developed model to investigate the effect of key design parameters on the peak strength, ultimate deformation capacity and plastic hinge length of RC walls under axial tension and cyclic lateral loading. On the basis of the analysis results, useful information were provided when designing or assessing the seismic behaviour of RC slender walls under coupled axial tension–flexure loading.

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