scholarly journals Numerical experimentation for the optimal design of reinforced rectangular concrete beams for singly reinforced sections

DYNA ◽  
2016 ◽  
Vol 83 (196) ◽  
pp. 134-142 ◽  
Author(s):  
Arnulfo Luévanos Rojas
Keyword(s):  
Optimal Design ◽  
Concrete Beams ◽  
Minimum Weight ◽  
Construction Materials ◽  
Optimal Solution ◽  
Minimum Cost ◽  
Problem Formulation ◽  
Design Solution ◽  
Design Variables ◽  
Numerical Experimentation

<p>This paper presents a model for the optimal design of reinforced rectangular concrete beams for singly reinforced sections. It develops an analytical approach to the problem, based on a criterion of minimum cost and minimum weight design with a reduced number of design variables. Representative examples are presented to illustrate the applicability of the formulation in accordance with building code requirements for structural concrete (ACI 318S-13), including the comments on the standards. A comparison is made between the optimal design solution and current design practice for reinforced rectangular concrete beams. The optimal solution for the design of reinforced rectangular concrete beams shows clearly that significant savings can be made in the costs of the construction materials used – i.e. reinforcement steel and concrete. In addition, the problem formulation can be applied using a nonlinear mathematical programming format.</p>

Optimal Design of Plastic Structures for Fixed and Shakedown Loadings

1973 ◽  
Vol 40 (2) ◽  
pp. 595-599 ◽  
Author(s):  
M. Z. Cohn ◽  
S. R. Parimi
Keyword(s):  
Optimal Design ◽  
Loading Condition ◽  
Minimum Weight ◽  
Optimal Solution ◽  
Failure Criteria ◽  
Optimal Designs ◽  
Design Solution ◽  
Variable Loading ◽  
Framed Structures ◽  
A Value

Optimal (minimum weight) solutions for plastic framed structures under shakedown conditions are found by linear programming. Designs that are optimal for two failure criteria (collapse under fixed loads and collapse under variable repeated loads) are then investigated. It is found that these designs are governed by the ratio of the specified factors defining the two failure criteria, i.e., for shakedown, λs and for collapse under fixed loading, λ. Below a certain value (λs/λ)min the optimal solution under fixed loading is also optimal for fixed and shakedown loading. Above a value (λs/λ)max the optimal design for variable loading is also optimal under the two loading conditions. For intermediate values of λs/λ the optimal design that simultaneously satisfies the two criteria is different from the optimal designs for each independent loading condition. An example illustrates the effect of λs/λ on the nature of the design solution.

scholarly journals Design Optimization of Composite Laminated Tube Based on Improved Niching Evolutionary Algorithm

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Sen Ma ◽  
Qilin Zhao ◽  
Darong Pan
Keyword(s):  
Optimal Design ◽  
Evolutionary Algorithms ◽  
Objective Function ◽  
Evolutionary Algorithm ◽  
Minimum Weight ◽  
Local Optimum ◽  
Optimal Result ◽  
Minimum Weight Design ◽  
Design Variables ◽  
Weight Design

A minimum weight design is developed for a composite laminated tube considering the number of plies as one of the design variables. The objective function is found to be complex, and more than one optimal design point may exist with different numbers of plies. Existing methods based on evolutionary algorithms tend to become trapped around a local optimum and can find no more than one optimal result per calculation. Aiming at the characteristics of the objective function, an improved evolutionary algorithm (INDE for short) is established based on niching technology. The formula for calculating the distance between individuals in the niching technology is improved to satisfy the minimum weight design for the composite laminated tube. As a result, the improved niching evolutionary algorithm offers better global search ability and can find more than one optimal result per calculation for different numbers of plies.

scholarly journals Energy saving optimal design and control of electromagnetic brake on passenger car

2019 ◽  
Vol 10 (1) ◽  
pp. 57-70
Author(s):  
Donghai Hu ◽  
Yanzhi Yan ◽  
Xiaoming Xu
Keyword(s):  
Energy Consumption ◽  
Optimal Design ◽  
Energy Saving ◽  
Prediction Models ◽  
Control Method ◽  
Optimal Solution ◽  
Electromagnetic Brake ◽  
Design Variables ◽  
And Control ◽  
Optimal Design And Control

Abstract. In this paper, the optimal design and control method of electromagnetic brake for a typical city driving cycle are studied to improve its energy consumption characteristics. The prediction models of the braking performance and power consumption for electromagnetic brake were established, and their accuracies were verified on the hardware of the loop simulation platform. Moreover, the energy consumption based on the ECE-EUDC driving condition was taken as the objective function, and a mathematical model for the optimal design of the electromagnetic brake was established. Genetic Algorithm was used to seek global optimal solution of these design variables on the premise of the given electrical and space constraints. Finally, the effect of thermodynamic properties of electromagnetic brake on the energy consumption characteristics was analyzed, and the energy saving control method of electromagnetic brake was also proposed. Experimental results show that the energy saving optimal design and control that this paper investigates can significantly improve the energy efficiency of electromagnetic brake.

scholarly journals Optimal design for rectangular isolated footings using the real soil pressure

2017 ◽  
Vol 37 (2) ◽  
pp. 25-33
Author(s):  
Arnulfo Luévanos Rojas ◽  
S López Chavarría ◽  
M Medina Elizondo
Keyword(s):  
Reinforced Concrete ◽  
Optimal Design ◽  
Classical Method ◽  
Design Method ◽  
Minimum Cost ◽  
Soil Pressure ◽  
Minimum Cost Design ◽  
Standard Design ◽  
Numerical Experimentation ◽  
Current Design

The standard design method (classical method) for reinforced concrete rectangular footings is: First, a dimension is proposed and should comply with the allowable stresses; subsequently, the effective depth is obtained from the maximum moment and is checked against the bending shear and the punching shear until, it complies with these conditions and, then, steel reinforcement is obtained, but it is not guarantee that the minimum cost will be obtained. This paper shows an optimal design for reinforced concrete rectangular footings using the new model. A numerical experimentation is presented to show the model capability to estimate the minimum cost design of the materials used for a rectangular footing that supports an axial load and moments in two directions in accordance to the building code requirements for structural concrete and commentary (ACI 318-13). Also, a comparison is made between the optimal design and current design for rectangular footings. The solutions show that the optimal design is more economical and more precise with respect to the current design, because standard design is done by trial and error. Then, the optimal design should be used to obtain the minimum cost design for reinforced concrete rectangular footings.

Optimal Design of Elastic Linkage Mechanisms With Multi-Frequency Constraints

1994 ◽  
Author(s):  
Zhang Xianmin ◽  
Shen Yunwen ◽  
Liu Hongzhao ◽  
Cao Weiqing
Keyword(s):  
Optimal Design ◽  
Minimum Weight ◽  
Design Sensitivity ◽  
Stability And Convergence ◽  
Bound Constraints ◽  
Frequency Constraints ◽  
Design Algorithm ◽  
Design Variables ◽  
Weight Design ◽  
Flexible Mechanisms

Abstract The paper presents a finite element method for minimum weight design of flexible mechanisms with multiple frequency constraints and upper and lower bound constraints on the design variables. The design algorithm developed in this paper is formulated in terms of the Kuhn-Tucker optimality criterion, in which two damping factors are introduced to guarantee the algorithm possesses good stability and convergence. The first and second order design sensitivity analysies of eigenvalues are presented and the values of the damping factors α and β are recommended. Results of three numerical examples show that the algorithm is stable and the optimal design can be obtained in lsee than fifteen iterations.

Design Optimization of the Flexspline in Harmonic Drive

2012 ◽  
Vol 215-216 ◽  
pp. 59-63 ◽  
Author(s):  
Juan Dai ◽  
Li Zhi Chen ◽  
Xiao Bing Pang
Keyword(s):  
Genetic Algorithm ◽  
Optimal Design ◽  
Design Optimization ◽  
Optimization Model ◽  
Design Solution ◽  
Harmonic Drive ◽  
Discrete Variables ◽  
Geometrical Constraint ◽  
Design Variables ◽  
Discrete Design Variables

In order to reduce the weight of harmonic drive (HD), the total volume of flexspline and circular spline was formulated and used as an objection function. Under the constraints including the condition on the strength of flexspline, the condition on averting the tooth top interference, the condition on the transmission ratio of HD and the geometrical constraint conditions of flexspline, a design optimization model with mixed discrete variables was established. For directly applying the optimal design solution of flexspline to manufacture, a manufacture-oriented method for dealing with mixed discrete design variables was used and the established model was solved by using an improved compound genetic algorithm. An optimal design example of flexspline was given and it shows that the proposed method is practical and effective.

Optimal Design of a Hydraulic Suspension Mechanism of Aircraft Recovery Vehicle

2014 ◽  
Vol 670-671 ◽  
pp. 886-891 ◽  
Author(s):  
Zhen Yu Hong ◽  
Peng Fei Zhang ◽  
Zhi Hua Xu
Keyword(s):  
Optimal Design ◽  
Theoretical Analysis ◽  
Axial Force ◽  
Optimal Solution ◽  
Hydraulic Cylinder ◽  
Initial Position ◽  
Hinge Joint ◽  
Scale Parameters ◽  
Design Variables ◽  
Aircraft Recovery

Through theoretical analysis of a suspension mechanism used for aircraft recovery vehicle, the mapping relationship between the hydraulic cylinder axial force and scale parameters of the suspension mechanism was built. With coordinate values of each hinge joint of the suspension mechanism in the initial position as design variables, the minimum hydraulic cylinder axial force was taken as evaluating index with reasonable constraints and optimal design of the hydraulic suspension mechanism was studied. The influence law of scale parameters to the axial force was discussed and coordinate alternation method was applied to find the optimal solution. The effectiveness of the method was indicated by an example.

Structural Analysis and Optimal Design of Lightweight Skate for Loading and Unloading

2013 ◽  
Vol 785-786 ◽  
pp. 1258-1261
Author(s):  
In Pyo Cha ◽  
Hee Jae Shin ◽  
Neung Gu Lee ◽  
Lee Ku Kwac ◽  
Hong Gun Kim
Keyword(s):  
Topology Optimization ◽  
Structural Analysis ◽  
Optimal Design ◽  
Optimization Techniques ◽  
Normal Operation ◽  
Stress And Strain ◽  
Initial Model ◽  
Design Variables ◽  
Model Set ◽  
Main Frame

Topology optimization and shape optimization of structural optimization techniques are applied to transport skate the lightweight. Skate properties by varying the design variables and minimize the maximum stress and strain in the normal operation, while reducing the volume of the objective function of optimal design and Skate the static strength of the constraints that should not degrade compared to the performance of the initial model. The skates were used in this study consists of the main frame, sub frame, roll, pin main frame only structural analysis and optimal design was performed using the finite element method. Simplified initial model set design area and it compared to SM45C, AA7075, CFRP, GFRP was using the topology optimization. Strength does not degrade compared to the initial model, decreased volume while minimizing the stress and strain results, the optimum design was achieved efficient lightweight.

scholarly journals Modeling, Simulation and Uncertain Optimization of the Gun Engraving System

Mathematics ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 398
Author(s):  
Tong Xin ◽  
Guolai Yang ◽  
Fengjie Xu ◽  
Quanzhao Sun ◽  
Alexandi Minak
Keyword(s):  
Performance Evaluation ◽  
Optimal Design ◽  
Resistance Force ◽  
Gas Temperature ◽  
Evaluation Indexes ◽  
Uncertain Optimization ◽  
Design Variables ◽  
Set Up ◽  
Rotating Band ◽  
Percent Decrease

The system designed to accomplish the engraving process of a rotating band projectile is called the gun engraving system. To obtain higher performance, the optimal design of the size parameters of the gun engraving system was carried out. First, a fluid–solid coupling computational model of the gun engraving system was built and validated by the gun launch experiment. Subsequently, three mathematic variable values, like performance evaluation indexes, were obtained. Second, a sensitivity analysis was performed, and four high-influence size parameters were selected as design variables. Finally, an optimization model based on the affine arithmetic was set up and solved, and then the optimized intervals of performance evaluation indexes were obtained. After the optimal design, the percent decrease of the maximum engraving resistance force ranged from 6.34% to 18.24%; the percent decrease of the maximum propellant gas temperature ranged from 1.91% to 7.45%; the percent increase of minimum pressure wave of the propellant gas ranged from 0.12% to 0.36%.

Configuration Robustness Analysis of the Optimal Design of Cable-Driven Manipulators

2016 ◽  
Vol 8 (6) ◽  
Author(s):  
Joshua T. Bryson ◽  
Xin Jin ◽  
Sunil K. Agrawal
Keyword(s):  
Optimal Design ◽  
Stochastic Optimization ◽  
High Dimension ◽  
Degrees Of Freedom ◽  
Robustness Analysis ◽  
Optimal Solution ◽  
Design Parameters ◽  
Robot Leg ◽  
Robot Performance

Designing an effective cable architecture for a cable-driven robot becomes challenging as the number of cables and degrees of freedom of the robot increase. A methodology has been previously developed to identify the optimal design of a cable-driven robot for a given task using stochastic optimization. This approach is effective in providing an optimal solution for robots with high-dimension design spaces, but does not provide insights into the robustness of the optimal solution to errors in the configuration parameters that arise in the implementation of a design. In this work, a methodology is developed to analyze the robustness of the performance of an optimal design to changes in the configuration parameters. This robustness analysis can be used to inform the implementation of the optimal design into a robot while taking into account the precision and tolerances of the implementation. An optimized cable-driven robot leg is used as a motivating example to illustrate the application of the configuration robustness analysis. Following the methodology, the effect on robot performance due to design variations is analyzed, and a modified design is developed which minimizes the potential performance degradations due to implementation errors in the design parameters. A robot leg is constructed and is used to validate the robustness analysis by demonstrating the predicted effects of variations in the design parameters on the performance of the robot.

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