Optimal design of a minimum weight thermal diffuser with constraint on the output thermal power flux

1982 ◽  
Vol 9 (1) ◽  
pp. 225-262 ◽  
Author(s):  
M. Delfour ◽  
G. Payre ◽  
J. -P. Zol�sio
Keyword(s):  
Optimal Design ◽  
Minimum Weight ◽  
Thermal Power ◽  
Power Flux ◽  
Thermal Diffuser

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.

The Optimal Design of a Functionally Graded Corrugated Cylindrical Shell under Axisymmetric Loading

2019 ◽  
Vol 20 (3-4) ◽  
pp. 387-398
Author(s):  
I. I. Andrianov ◽  
J. Awrejcewicz ◽  
A.A. Diskovsky
Keyword(s):  
Optimal Design ◽  
Design Theory ◽  
High Efficiency ◽  
Minimum Weight ◽  
Functionally Graded ◽  
Corrugated Shell ◽  
Maximum Stiffness ◽  
Hydrostatic Load ◽  
Homogenization Approach ◽  
Corrugated Cylindrical Shell

AbstractOptimization of parameters of the corrugated shell aims to achieve its minimum weight while keeping maximum stiffness ability. How an introduction of functionally graded corrugations resulted in improved efficiency of this thin-walled structure is demonstrated. The corrugations are graded varying their pitch. The effect of variation in pitch is studied. Homogenization approach gives explicit expressions to calculate the equivalent shell properties. Then well-elaborate methods of optimal design theory are used. The illustrative examples for hydrostatic load demonstrate a high efficiency of the used method.

scholarly journals Modal Approximation Based Optimal Design of Dynamically Loaded Plastic Structures

2017 ◽  
Author(s):  
Bartlomiej Dominik Blachowski ◽  
Piotr Tauzowski ◽  
Janos Logo
Keyword(s):  
Optimal Design ◽  
Deformation Process ◽  
Minimum Weight ◽  
Optimization Technique ◽  
Design Procedure ◽  
Inertial Forces ◽  
Constant Acceleration ◽  
Weight Structure ◽  
Plastic Displacement

The purpose of this study is to present an optimal design procedure for elasto-plastic structures subjected to impact loading. The proposed method is based on mode approximation of the displacement field and assumption of constant acceleration of impacted structure during whole time of deformation process until the plastic displacement limit is reached. Derivation of the method begins with the application of the principle of conservation of linear momentum, followed by determination of inertial forces. The final stage of the method utilizes an optimization technique in order to find a minimum weight structure. Eventually, effectiveness and usefulness of the proposed method is demonstrated on the example of a planar truss structure subjected to dynamic loading caused by a mass impacting the structure with a given initial velocity.

Optimal Design of PID Controller Based Sampe-Jaya Algorithm for Load Frequency Control of Linear and Nonlinear Multi-Area Thermal Power Systems

2020 ◽  
Vol 50 ◽  
pp. 79-93
Author(s):  
Adel A. Abou El Ela ◽  
Ragab A. El-Sehiemy ◽  
Abdullah M. Shaheen ◽  
Abd El Galil Diab
Keyword(s):  
Optimal Design ◽  
Power Systems ◽  
Pid Controller ◽  
Frequency Control ◽  
Thermal Power ◽  
Absolute Error ◽  
Load Frequency Control ◽  
Jaya Algorithm ◽  
Load Frequency ◽  
The Impact

Modern multi-area power systems are in persistent facing to imbalances in power generation and consumption which directly causes frequency and tie-line power fluctuations in each area. This paper deals with the load frequency control (LFC) problem where the control objective of regulating their error signals despite the presences of several external load disturbances. It proposes an optimal design of proportional integral derivative controller (PID) based on a novel version of Jaya algorithm called self-adaptive multi-population elitist (SAMPE) Jaya optimizer. A filter with derivative term is integrated with PID controller to alleviate the impact of noise in the input signal. A time domain based-objective functions are investigated such as integral time-multiplied absolute value of the error (ITAE) and integral of absolute error (IAE). Both SAMPE-Jaya and Jaya optimizers are employed to optimally tune the PID parameters for interconnected power systems comprising two non-reheat thermal areas. Three test cases are performed with various load disturbances in both areas individually and simultaneaously. Also, the practical physical constraints related to generation rate constraint (GRC) with its nonlinearity characteristics are taken into account. In addition, the obtained results using the designed PID controller based on SAMPE-Jaya are compared with various reported techniques. These simulated comparisons declare the great efficiency and the high superiority of the designed PID controller based on SAMPE-Jaya.

scholarly journals Clean-development-mechanism-based optimal hydropower capacity design

2018 ◽  
Vol 20 (6) ◽  
pp. 1401-1418 ◽  
Author(s):  
Amir Hatamkhani ◽  
Hosein Alizadeh
Keyword(s):  
Optimal Design ◽  
Clean Development Mechanism ◽  
Thermal Power ◽  
Market Price ◽  
Mixed Integer ◽  
Optimization Approach ◽  
Hydropower Project ◽  
Thermal Plant ◽  
Modelling Framework ◽  
Development Mechanism

Abstract This paper deals with optimal design of a hydropower project's capacity when an analyst may take into account different economic analysis approaches and considerations including market price method, alternative thermal power plant method, externalities and clean development mechanism (CDM). We formulate the problem using mixed-integer nonlinear programming including an economic objective function and governing hydropower constraints. Due to non-convexity of the program, we employ an effective simulation-optimization approach coupling particle swarm optimization (PSO) and Water Evaluation and Planning (WEAP) software which we customize for hydropower simulation using scripting capabilities of the software. The developed modelling framework is applied to the Karun II hydropower project in Iran, where we aim CDM-based optimal design of the project and also compare two economic hydropower analysis methods, i.e. market price and alternative thermal plant. Results show how inclusion of externality and CDM can affect the project's design and measures.

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.

Optimal Design of Electric Overhead Crane Girders

1984 ◽  
Vol 106 (2) ◽  
pp. 203-208
Author(s):  
S. W. Cho ◽  
B. M. Kwak
Keyword(s):  
Sensitivity Analysis ◽  
Optimal Design ◽  
Mathematical Programming ◽  
Computer Program ◽  
Optimum Design ◽  
Minimum Weight ◽  
Steepest Descent ◽  
Overhead Crane ◽  
Simply Supported ◽  
Steepest Descent Algorithm

An optimal design for minimum weight bridge girders of electric overhead traveling cranes is presented. The welded box-type girder is modeled as a simply supported beam. A generalized steepest descent algorithm is adopted for mathematical programming, which includes constraints on stress, displacement, buckling, and sizes. A computer program capable of designing girders according to CMAA, DIN, BS, and JIS specifications is developed. Numerical comparisons with existing girders for those four specifications are given. A sensitivity analysis of the optimum design with respect to parameters affecting the design is studied for each specification.

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