scholarly journals Methodological approach to investigate the behavior of the structure under dynamic loading using multiple criteria decision-making method

2018 ◽  
Vol 1 (2) ◽  
Author(s):  
Josef Oleksik ◽  
Thomas Vietor ◽  
Srivatsaa Natarajan
Keyword(s):  
Decision Making ◽  
Energy Absorption ◽  
Dynamic Loading ◽  
Hybrid Material ◽  
Methodological Approach ◽  
Multiple Criteria Decision Making ◽  
Metal Composite ◽  
Aluminum Composite ◽  
Thermoplastic Matrix ◽  
Bending Load

The main objective of this article is to develop a support approach for designers in the concept phase of the design process. In this paper, two different structures are investigated with metal, composite and hybrid material under dynamic loading with multiple strain rates. The optimum choice of material and structural combination is found by a methodological approach using a Multi Criteria Decision Making Method (MCDM). It uses a stepwise procedure in evaluating the significance of each criterion and ranks the different alternatives. This method is applied to solve various problems in the field of economics, engineering, management. In this article, COPRAS is used to rank different material and structural combination.Cylindrical and rectangular structures are investigated under axial and 3-point bending load. Moreover, three different constellations of material widen the comparison; they are steel and aluminum, composite material with carbon fiber and thermoplastic matrix and hybrid material, with a combination of composite and metal. The output parameters from the simulation such as energy absorption and force, are further mathematically converted to specific energy absorption (SEA), crash-force-efficiency (CFE) and load non-uniformity (LU). PAM-Crash is used as a solver for simulation.

Bending Performance Analysis of Aluminum-Composite Hybrid Tube Beams

2006 ◽  
Vol 306-308 ◽  
pp. 769-774 ◽  
Author(s):  
Sung Hyuk Lee ◽  
Hyung Jin Kim ◽  
Nak Sam Choi
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Energy Absorption ◽  
Bending Strength ◽  
Composite Layer ◽  
Strain Curve ◽  
Aluminum Composite ◽  
Bending Performance ◽  
Element Simulation ◽  
Bending Load

Bending deformation and energy absorption characteristics of aluminum-composite hybrid tube beams have been analyzed for improvement in the bending performance of aluminum space frame by using experimental tests combined with theoretical and finite element analyses. Hybrid tube beams composed of glass fabric/epoxy layer wrapped around on aluminum tube were made in autoclave with the recommended curing cycle. Basic properties of aluminum material used for initial input data of the finite element simulation and theoretical analysis were obtained from the true stress-true strain curve of specimen which had bean extracted from the Al tube beam. A modified theoretical model was developed to predict the resistance to the collapse of hybrid tube beams subjected to a bending load. Theoretical moment-rotation angle curves of hybrid tube beams were in good agreement with experimental ones, which was comparable to the results obtained from finite element simulation. Hybrid tube beams strengthened by composite layer on the whole web and flange showed an excellent bending strength and energy absorption capability.

Improving the energy-absorbing properties of hybrid aluminum-composite tubes using nanofillers for crashworthiness applications

2020 ◽  
pp. 095440622094226
Author(s):  
A Praveen Kumar ◽  
D Maneiah ◽  
L Ponraj Sankar
Keyword(s):  
Energy Absorption ◽  
Metal Composite ◽  
Multiwalled Carbon ◽  
Aluminum Composite ◽  
Basalt Glass ◽  
Cylindrical Tubes ◽  
Thin Walled ◽  
Crushing Behavior ◽  
Energy Absorbing ◽  
The Impact

Thin-walled tubular configurations with hybridization concept have been gained special consideration in recent years owing to their substantial balance between light-weight characteristics and crashworthiness performance. In this context, some research studies have been concentrated on the feasibility of a thin-walled metal-composite hybrid tube. It is also eminent that the impact energy absorption capability of such hybrid tubes can further be enhanced through modification of the epoxy matrix by adding nanofillers. In this research article, aluminum-based multiwalled carbon nanotubes reinforced epoxy composite cylindrical tubes are introduced, and their corresponding quasi-static crushing behavior, subjected to lateral loading is examined experimentally. The influence of the number of fabric plies (2, 3, and 4) and type of fabric (basalt, glass) of the composite part on the crashworthiness characteristics was evaluated. The overall outcomes revealed that the proposed hybrid tube samples showed outstanding energy absorption characteristics, comprising a stable crush force–deformation response and better specific energy absorption. It is also noted that the deformation behavior and energy absorption capability of the aluminum tubes could be considerably improved by applying a nanocomposite-wrapped plies.

scholarly journals A New Grey Approach for Using SWARA and PIPRECIA Methods in a Group Decision-Making Environment

Mathematics ◽  
2021 ◽  
Vol 9 (13) ◽  
pp. 1554
Author(s):  
Dragiša Stanujkić ◽  
Darjan Karabašević ◽  
Gabrijela Popović ◽  
Predrag S. Stanimirović ◽  
Muzafer Saračević ◽  
...  
Keyword(s):  
Decision Making ◽  
Group Decision Making ◽  
Group Decision ◽  
Multiple Criteria Decision Making ◽  
Grey System Theory ◽  
Multiple Criteria ◽  
Decision Making Process ◽  
Grey System ◽  
Criteria Weights

The environment in which the decision-making process takes place is often characterized by uncertainty and vagueness and, because of that, sometimes it is very hard to express the criteria weights with crisp numbers. Therefore, the application of the Grey System Theory, i.e., grey numbers, in this case, is very convenient when it comes to determination of the criteria weights with partially known information. Besides, the criteria weights have a significant role in the multiple criteria decision-making process. Many ordinary multiple criteria decision-making methods are adapted for using grey numbers, and this is the case in this article as well. A new grey extension of the certain multiple criteria decision-making methods for the determination of the criteria weights is proposed. Therefore, the article aims to propose a new extension of the Step-wise Weight Assessment Ratio Analysis (SWARA) and PIvot Pairwise Relative Criteria Importance Assessment (PIPRECIA) methods adapted for group decision-making. In the proposed approach, attitudes of decision-makers are transformed into grey group attitudes, which allows taking advantage of the benefit that grey numbers provide over crisp numbers. The main advantage of the proposed approach in relation to the use of crisp numbers is the ability to conduct different analyses, i.e., considering different scenarios, such as pessimistic, optimistic, and so on. By varying the value of the whitening coefficient, different weights of the criteria can be obtained, and it should be emphasized that this approach gives the same weights as in the case of crisp numbers when the whitening coefficient has a value of 0.5. In addition, in this approach, the grey number was formed based on the median value of collected responses because it better maintains the deviation from the normal distribution of the collected responses. The application of the proposed approach was considered through two numerical illustrations, based on which appropriate conclusions were drawn.

Renewable energy selection based on a new entropy and dissimilarity measure on an interval-valued neutrosophic set

2021 ◽  
pp. 1-18
Author(s):  
ShuoYan Chou ◽  
Truong ThiThuy Duong ◽  
Nguyen Xuan Thao
Keyword(s):  
Decision Making ◽  
Renewable Energy ◽  
Membership Function ◽  
Fossil Fuels ◽  
Multiple Criteria Decision Making ◽  
Clean Energy ◽  
Dissimilarity Measure ◽  
Neutrosophic Set ◽  
Trade Offs ◽  
And Performance

Energy plays a central part in economic development, yet alongside fossil fuels bring vast environmental impact. In recent years, renewable energy has gradually become a viable source for clean energy to alleviate and decouple with a negative connotation. Different types of renewable energy are not without trade-offs beyond costs and performance. Multiple-criteria decision-making (MCDM) has become one of the most prominent tools in making decisions with multiple conflicting criteria existing in many complex real-world problems. Information obtained for decision making may be ambiguous or uncertain. Neutrosophic is an extension of fuzzy set types with three membership functions: truth membership function, falsity membership function and indeterminacy membership function. It is a useful tool when dealing with uncertainty issues. Entropy measures the uncertainty of information under neutrosophic circumstances which can be used to identify the weights of criteria in MCDM model. Meanwhile, the dissimilarity measure is useful in dealing with the ranking of alternatives in term of distance. This article proposes to build a new entropy and dissimilarity measure as well as to construct a novel MCDM model based on them to improve the inclusiveness of the perspectives for decision making. In this paper, we also give out a case study of using this model through the process of a renewable energy selection scenario in Taiwan performed and assessed.

scholarly journals Evaluating the Implementation of the “Build-Back-Better” Concept for Critical Infrastructure Systems: Lessons from Saint-Martin’s Island Following Hurricane Irma

2021 ◽  
Vol 13 (6) ◽  
pp. 3133
Author(s):  
Rita Der Sarkissian ◽  
Anas Dabaj ◽  
Youssef Diab ◽  
Marc Vuillet
Keyword(s):  
Decision Making ◽  
Conceptual Analysis ◽  
Scientific Literature ◽  
Critical Infrastructure ◽  
Methodological Approach ◽  
Infrastructure Systems ◽  
Before And After ◽  
Study Offer ◽  
Hurricane Irma ◽  
Operational Aspects

A limited number of studies in the scientific literature discuss the “Build-Back-Better” (BBB) critical infrastructure (CI) concept. Investigations of its operational aspects and its efficient implementation are even rarer. The term “Better” in BBB is often confusing to practitioners and leads to unclear and non-uniform objectives for guiding accurate decision-making. In an attempt to fill these gaps, this study offers a conceptual analysis of BBB’s operational aspects by examining the term “Better”. In its methodological approach, this study evaluates the state of Saint-Martin’s CI before and after Hurricane Irma and, accordingly, reveals the indicators to assess during reconstruction projects. The proposed methods offer practitioners a guidance tool for planning efficient BBB CI projects or for evaluating ongoing programs through the established BBB evaluation grid. Key findings of the study offer insights and a new conceptual equation of the BBB CI by revealing the holistic and interdisciplinary connotations behind the term “Better” CI: “Build-Back-resilient”, “Build-Back-sustainable”, and “Build-Back-accessible to all and upgraded CI”. The proposed explanations can facilitate the efficient application of BBB for CI by operators, stakeholders, and practitioners and can help them to contextualize the term “Better” with respect to their area and its CI systems.

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