Structural optimization of a composite launch tube of man portable air defense system

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Efecan Yar ◽  
Erdem Acar
Keyword(s):  
Structural Optimization ◽  
Minimum Weight ◽  
Cost Effective ◽  
Defense System ◽  
Content Type ◽  
Air Defense ◽  
Design Variables ◽  
Optimum Cost ◽  
Effective Design ◽  
Launch Tube

Purpose The purpose of this paper is to find the optimum configuration of the composite launch tube currently being developed in Roketsan. The winding thicknesses and winding angles of the launch tube are selected as design variables, and three different composite material alternatives are evaluated: glass/epoxy, carbon/epoxy and aramid/epoxy. Design/methodology/approach In this study, structural optimization of a composite launch tube of man portable air defense system is conducted. To achieve a cost-effective design, a cost scoring table that includes structural weight, material cost, availability and manufacturability is first introduced. Then, optimization for minimum weight is conducted, where the winding thicknesses and winding angle are taken as design variables, and the safety factor value obtained by using the Tsai–Wu damage criterion is used as constraint. A surrogate-based optimization approach is used where various options for surrogate models are evaluated. Glass/epoxy, carbon/epoxy and aramid/epoxy are considered as alternative materials for the launch tube. Finally, the selection of the most cost-effective design is performed to achieve optimum cost. Findings Carbon fiber-reinforced epoxy matrix material provides the optimum cost-effective design for the launch tube. Practical implications The findings of the paper can be used to design more cost-efficient composite launch tube currently being developed in Roketsan. Originality/value The existing studies are based on a design approach to achieve minimum weight of the launch tubes, whereas this study introduces a design approach to achieve optimum cost.

A new laminates encoding scheme for the genetic algorithm-based optimization of stiffened composite panels

2014 ◽  
Vol 31 (1) ◽  
pp. 33-47
Author(s):  
Aleksandr Cherniaev
Keyword(s):  
Genetic Algorithm ◽  
Minimum Weight ◽  
Composite Panel ◽  
Computational Time ◽  
Stiffened Panel ◽  
Composite Panels ◽  
Encoding Scheme ◽  
Content Type ◽  
Design Variables ◽  
Stiffened Composite Panels

Purpose – The genetic algorithm (GA) technique is widely used for the optimization of stiffened composite panels. It is based on sequential execution of a number of specific operators, including the encoding of particular design variables. For instance, in the case of a stiffened composite panel, the design variables that need to be encoded are: the number of plies and their stacking sequences in the panel skin and stiffeners. This paper aims to present a novel, implicit, heuristic approach for encoding composite laminates and, through its use, demonstrates an improvement in the optimization process. Design/methodology/approach – The stiffened panel optimization has been formulated as a constrained discrete minimum-weight design problem. GAs, which use both new encoding schemes and those previously described in the literature, have been used to find near-optimal solutions to the formulated problem. The influence of the new encoding scheme on the searching capabilities of the GA has been investigated using comparative analysis of the optimization results. Findings – The new encoding scheme allows the definition of stacking sequences in composites using shorter symbolic representations as compared with standard encoding operators and, as a result of this, a reduction in the problem design space. According to numerical experiments performed in this work, this feature enables GA to obtain near-optimal designs using smaller population sizes than those required if standard encoding schemes are used. Originality/value – The approach to encoding laminates presented in this paper is based on the original heuristics. In the context of GA-based optimization of stiffened composite panels, the use of the new approach rather than the standard encoding technique can lead to a significant reduction in computational time employed.

Cost-Optimal Design of Dry Cooling Towers Through Mathematical Programming Techniques

1989 ◽  
Vol 111 (2) ◽  
pp. 322-327 ◽  
Author(s):  
J. D. Buys ◽  
D. G. Kro¨ger
Keyword(s):  
Objective Function ◽  
Cooling System ◽  
Cost Effective ◽  
Operating Conditions ◽  
Variable Metric ◽  
Design Variables ◽  
Specific Performance ◽  
Programming Techniques ◽  
Effective Design ◽  
Dry Cooling

The Constrained Variable Metric Algorithm is chosen to minimize the objective function (cost) in the design of a natural draft dry cooling tower. An existing cooling system design that has specific performance characteristics under prescribed operating conditions is selected as a reference unit. By changing design variables, but not exceeding prescribed constraints, a more cost-effective design is achieved. The influence of various parameters, and the sensitivity of the objective function to these parameters, are evaluated.

Multi-Material and Multi-Joint Topology Optimization for Lightweight and Cost-Effective Design

2021 ◽  
Author(s):  
Luke Crispo ◽  
Stephen William Knox Roper ◽  
Rubens Bohrer ◽  
Rosalie Morin ◽  
Il Yong Kim
Keyword(s):  
Topology Optimization ◽  
Dissimilar Materials ◽  
Cost Effective ◽  
Unstructured Meshes ◽  
Parameter Study ◽  
Design Variables ◽  
Research Themes ◽  
Multiple Material ◽  
Optimization Methodology ◽  
Effective Design

Abstract Lightweighting and cost reduction are overarching research themes in aerospace and automotive industries, leading to the exploration of new materials, advanced manufacturing methods, and design optimization algorithms. Multi-material topology optimization is an important tool that can generate unconventional designs leveraging the differing mechanical properties of multiple material types to increase performance. However, these approaches do not consider joining design during optimization, which can ultimately result in higher cost, worse performance, and unrealistic designs that must be altered in the interpretation stage. This work presents a multi-material and multi-joint topology optimization methodology that models joints at the interfaces between dissimilar materials, controls the joining pattern using joint design variables, and reduces cost through the addition of a joining cost constraint. Design variable interpolation schemes, interface detection for unstructured meshes, and sensitivity analysis are outlined in detail in this paper. The approach is applied to a real-world rocker arm geometry to demonstrate the importance of considering joints during multi-material topology optimization. The results of the numerical example indicate that the methodology can successfully detect interfaces in unstructured meshes and strategically place joints to maximize stiffness of the structure. A parameter study of various joining cost constraint levels illustrates how the optimizer alters part topology and joining design to reduce cost.

Design and Analysis of Commercial Automotive Vehicle Brake Pedal

2015 ◽  
Vol 813-814 ◽  
pp. 964-971
Author(s):  
Ghadage Ganesh ◽  
Pawar Unmesh ◽  
Satish S. Kadam
Keyword(s):  
Reaction Time ◽  
Weight Reduction ◽  
Cost Effective ◽  
Design Solution ◽  
Brake Pedal ◽  
Automotive Vehicle ◽  
Design Structure ◽  
Optimum Cost ◽  
Effective Design

Over the years, designers have been developing various brake pedals in a bid to eliminate the operator’s risk of pressing the wrong pedal and to reduce his or her braking reaction time. One of the effective methods for reducing weight of trucks brake pedal is to change the design structure of it. The brake pedal is designed and analysed using Ansys 14.0. Different materials are used for the effective design of brake pedal with weight reduction of pedal and improved grip between foot and the pedal. The FEA results obtained and discussed herein confer optimum, cost effective design solution, easy to manufacture, and exhibits better grip.

Comparative Structural Optimization Study of Composite and Aluminum Horizontal Tail Plane of a Helicopter

2019 ◽  
Author(s):  
Bertan Arpacioglu ◽  
Altan Kayran
Keyword(s):  
Structural Optimization ◽  
Minimum Weight ◽  
Local Buckling ◽  
Laminated Composite ◽  
Element Model ◽  
Aerodynamic Load ◽  
Preliminary Design ◽  
Design Phase ◽  
Design Variables ◽  
Discrete Design Variables

Abstract This work presents structural optimization studies of aluminum and composite material horizontal tail plane of a helicopter by using MSC. NASTRAN SOL200 optimization capabilities. Structural design process starts from conceptual design phase, and structural layout design is performed by using CATIA. In the preliminary design phase, study focuses on the minimum weight optimization with multiple design variables and similar constraints for both materials. Aerodynamic load calculation is performed using ANSYS and the finite element model of the horizontal tail plane is created by using MSC.PATRAN. According to the characteristics of materials, design variables are chosen. For the aluminum horizontal tail, thickness and flange areas are used as the design variables; and for composite horizontal tail, attention is mainly focused on the ply numbers and ply orientation angles of the laminated composite panels. By considering the manufacturability issues, discrete design variables are used. For three different mesh densities, different initial values of the design variables, and similar design constraints, optimizations are repeated and the results of optimizations are examined and compared with each other. In the optimizations performed, constraints are taken as strength and local buckling constraints. It is shown that the optimization methodology used in this study gives confident results for optimizing structures in the preliminary design phase.

The cost-effectiveness of insulin analogs and regular insulin for diabetes control: a case study in Iran

2020 ◽  
Vol 33 (4/5) ◽  
pp. 323-331
Author(s):  
Mohsen pakdaman ◽  
Raheleh akbari ◽  
Hamid reza Dehghan ◽  
Asra Asgharzadeh ◽  
Mahdieh Namayandeh
Keyword(s):  
Cost Effectiveness ◽  
Cost Effective ◽  
Regular Insulin ◽  
Diabetes Control ◽  
Diabetic Patients ◽  
Insulin Analogs ◽  
Content Type ◽  
Patients With Diabetes ◽  
The Government ◽  
The Cost

PurposeFor years, traditional techniques have been used for diabetes treatment. There are two major types of insulin: insulin analogs and regular insulin. Insulin analogs are similar to regular insulin and lead to changes in pharmacokinetic and pharmacodynamic properties. The purpose of the present research was to determine the cost-effectiveness of insulin analogs versus regular insulin for diabetes control in Yazd Diabetes Center in 2017.Design/methodology/approachIn this descriptive–analytical research, the cost-effectiveness index was used to compare insulin analogs and regular insulin (pen/vial) for treatment of diabetes. Data were analyzed in the TreeAge Software and a decision tree was constructed. A 10% discount rate was used for ICER sensitivity analysis. Cost-effectiveness was examined from a provider's perspective.FindingsQALY was calculated to be 0.2 for diabetic patients using insulin analogs and 0.05 for those using regular insulin. The average cost was $3.228 for analog users and $1.826 for regular insulin users. An ICER of $0.093506/QALY was obtained. The present findings suggest that insulin analogs are more cost-effective than regular insulin.Originality/valueThis study was conducted using a cost-effectiveness analysis to evaluate insulin analogs versus regular insulin in controlling diabetes. The results of study are helpful to the government to allocate more resources to apply the cost-effective method of the treatment and to protect patients with diabetes from the high cost of treatment.

Price structures for electricity supply and potential consequences for building services systems

2021 ◽  
pp. 014362442199081
Author(s):  
Roger Hitchin
Keyword(s):  
Cost Effective ◽  
Building Design ◽  
Electricity Supply ◽  
Cooling Systems ◽  
Price Structure ◽  
Heating And Cooling ◽  
Future System ◽  
The Cost ◽  
Supply Systems ◽  
Effective Design

Policies to reduce carbon emissions are leading to substantial changes in the demand for electricity and to the structure of electricity supply systems, which will alter the cost structure of electricity supply. This can be expected to result in corresponding changes to the price structure faced by customers. This note is an initial exploration of how possible new price structures may impact on HVAC system and building design and use. Changes in the price structure of electricity supply (separately from changes in price levels) can significantly affect the cost-effective design and operation of building services systems; especially of heating and cooling systems. The nature and implications of these changes can have important implications for future system design and operation.

scholarly journals Graph based discrete optimization in structural dynamics

2014 ◽  
Vol 62 (1) ◽  
pp. 91-102
Author(s):  
B. Blachowski ◽  
W. Gutkowski
Keyword(s):  
Structural Optimization ◽  
Minimum Weight ◽  
Continuous Optimization ◽  
Graph Representation ◽  
Wind Loading ◽  
Transmission Tower ◽  
Simple Method ◽  
Deterministic Dynamic ◽  
Starting Point ◽  
Discrete Values

Abstract In this study, a relatively simple method of discrete structural optimization with dynamic loads is presented. It is based on a tree graph, representing discrete values of the structural weight. In practical design, the number of such values may be very large. This is because they are equal to the combination numbers, arising from numbers of structural members and prefabricated elements. The starting point of the method is the weight obtained from continuous optimization, which is assumed to be the lower bound of all possible discrete weights. Applying the graph, it is possible to find a set of weights close to the continuous solution. The smallest of these values, fulfilling constraints, is assumed to be the discrete minimum weight solution. Constraints can be imposed on stresses, displacements and accelerations. The short outline of the method is presented in Sec. 2. The idea of discrete structural optimization by means of graphs. The knowledge needed to apply the method is limited to the FEM and graph representation. The paper is illustrated with two examples. The first one deals with a transmission tower subjected to stochastic wind loading. The second one with a composite floor subjected to deterministic dynamic forces, coming from the synchronized crowd activities, like dance or aerobic.

Sign in / Sign up

Export Citation Format

Share Document