A Methodology for Minimum Weight Optimal Design of Fibre-Reinforced Laminated Structures Accounting for Manufacturing Uncertainties

2009 ◽  
Author(s):  
M. Walker ◽  
R. Hamilton
Keyword(s):  
Optimal Design ◽  
Minimum Weight ◽  
Laminated Structures

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.

scholarly journals Synergistic effects of halloysite nanotubes with metal and phosphorus additives on the optimal design of eco-friendly sandwich panels with maximum flame resistance and minimum weight

2021 ◽  
Vol 11 (1) ◽  
pp. 252-265
Author(s):  
Saeed Kamarian ◽  
Ruiwen Yu ◽  
Jung-il Song
Keyword(s):  
Optimal Design ◽  
Failure Modes ◽  
Sandwich Structures ◽  
Synergistic Effects ◽  
Minimum Weight ◽  
Computational Cost ◽  
Sandwich Panels ◽  
Halloysite Nanotubes ◽  
Flame Resistance ◽  
Cone Calorimeter Test

Abstract The present work addresses the optimal design of sandwich panels made of flax fabric (FF)/vinyl ester (VE) composite face sheets and honeycomb VE core. The sandwich structures are first optimized in terms of flammability by obtaining the best combination of ammonium polyphosphate (APP), halloysite nanotube (HNT), and magnesium hydroxide (MH) as three flame retardants (FRs). Using the Taguchi method and horizontal burning test, it is shown that [6, 3, and 3%] and [1, 0.5, and 0%] are the optimal combinations of APP, HNT, and MH for the face sheets and core, respectively. Cone calorimeter test results indicate that the optimal FR combinations significantly decrease the mass lost rate (MLR), heat rate release (HRR), total smoke release (TSR), and maximum average release heat emission (MARHE). The FR sandwich structures are then geometrically optimized under compressive loads based on their weight. Different failure modes are considered as the design constraints of the optimization problem. Imperialist competitive algorithm (ICA), as a powerful meta-heuristic algorithm, is implemented to considerably reduce the computational cost of the optimization process. The results of this study show that proper combinations of FR additives can increase the flame retardancy while decreasing the weight of sandwich panels.

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.

Efficient Procedure for Robust Optimal Design of Aerospace Laminated Structures

2017 ◽  
Author(s):  
Francesco Noziglia ◽  
Paolo Rigato ◽  
Enrico Cestino ◽  
Giacomo Frulla ◽  
Alfredo Arias-Montano
Keyword(s):  
Optimal Design ◽  
Efficient Procedure ◽  
Robust Optimal Design ◽  
Laminated Structures
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