scholarly journals Optimization of Composite Fracture Properties: Method, Validation, and Applications

2016 ◽  
Vol 83 (7) ◽  
Author(s):  
Grace X. Gu ◽  
Leon Dimas ◽  
Zhao Qin ◽  
Markus J. Buehler
Keyword(s):  
Optimization Algorithm ◽  
Material Properties ◽  
Building Blocks ◽  
Test Case ◽  
Brute Force ◽  
Vast Number ◽  
Engineering Problems ◽  
Brute Force Method ◽  
Optimization Parameters ◽  
Underlying Mechanisms

A paradigm in nature is to architect composites with excellent material properties compared to its constituents, which themselves often have contrasting mechanical behavior. Most engineering materials sacrifice strength for toughness, whereas natural materials do not face this tradeoff. However, biology's designs, adapted for organism survival, may have features not needed for some engineering applications. Here, we postulate that mimicking nature's elegant use of multimaterial phases can lead to better optimization of engineered materials. We employ an optimization algorithm to explore and design composites using soft and stiff building blocks to study the underlying mechanisms of nature's tough materials. For different applications, optimization parameters may vary. Validation of the algorithm is carried out using a test suite of cases without cracks to optimize for stiffness and compliance individually. A test case with a crack is also performed to optimize for toughness. The validation shows excellent agreement between geometries obtained from the optimization algorithm and the brute force method. This study uses different objective functions to optimize toughness, stiffness and toughness, and compliance and toughness. The algorithm presented here can provide researchers a way to tune material properties for a vast number of engineering problems by adjusting the distribution of soft and stiff materials.

scholarly journals Automatic Makers as a Source for Olympiad Tasks

2021 ◽  
pp. 75-82
Author(s):  
Pavel S. PANKOV ◽  
Taalaibek M. IMANALIEV ◽  
Azret A. KENZHALIEV
Keyword(s):  
Initial Data ◽  
Building Block ◽  
Small Volume ◽  
Building Blocks ◽  
Brute Force ◽  
Simple Process ◽  
Force Method ◽  
Brute Force Method ◽  
Main Operation ◽  
Model Customization

Automatic maker is meant as a device to produce (or compose) things by itself, by a model, customization or a program. Nowadays the most advanced automatic makers in mass use are 3D-printers.The purpose of the paper is to present methods of generating various Olympiad tasks by using evident images of virtual automatic makers. As a perspective, production (performing) of processes is also considered (as automatic 4D-makers). Besides of the main operation: putting a pixel (voxel), the following primitives with virtual things can be involved: cutting; gluing; putting a building block; erasing a building block; copying a fragment, (for 4D-) shifting a building block. Tasks are generated naturally: to make a given thing (perform a given simple process) optimally in any sense (with respect to time; to number of primitives; to number of building blocks etc.). Such tasks are well-understood, have short formulations and are difficult to be solved even with initial data of small volume; a “brute force” method is either inapplicable or gives too overestimate of complexity.

scholarly journals Buyer Inspired Meta-Heuristic Optimization Algorithm

2020 ◽  
Vol 10 (1) ◽  
pp. 194-219 ◽  
Author(s):  
Sanjoy Debnath ◽  
Wasim Arif ◽  
Srimanta Baishya
Keyword(s):  
Optimization Algorithm ◽  
Optimization Technique ◽  
Statistical Test ◽  
Heuristic Optimization ◽  
Product Choice ◽  
Exploration And Exploitation ◽  
The Social ◽  
Engineering Problems ◽  
The Mean

AbstractNature inspired swarm based meta-heuristic optimization technique is getting considerable attention and established to be very competitive with evolution based and physical based algorithms. This paper proposes a novel Buyer Inspired Meta-heuristic optimization Algorithm (BIMA) inspired form the social behaviour of human being in searching and bargaining for products. In BIMA, exploration and exploitation are achieved through shop to shop hoping and bargaining for products to be purchased based on cost, quality of the product, choice and distance to the shop. Comprehensive simulations are performed on 23 standard mathematical and CEC2017 benchmark functions and 3 engineering problems. An exhaustive comparative analysis with other algorithms is done by performing 30 independent runs and comparing the mean, standard deviation as well as by performing statistical test. The results showed significant improvement in terms of optimum value, convergence speed, and is also statistically more significant in comparison to most of the reported popular algorithms.

Hydrogen’s Peculiar Effect on Material Properties: Do We Need to Be Concerned About Hydrogen Transport in Pipelines?

2021 ◽  
Author(s):  
Erling Østby ◽  
Bjørn-Andreas Hugaas ◽  
Agnes Marie Horn
Keyword(s):  
Mechanical Properties ◽  
Material Properties ◽  
Reliable Data ◽  
Hydrogen Gas ◽  
Decision Makers ◽  
Hydrogen Transport ◽  
Offshore Pipelines ◽  
Vast Number ◽  
Technical Aspects ◽  
Controversial Topic

Abstract Considering the vast number of articles that have been published during the last 150 years related to hydrogen embrittlement and the multiple attempts to explain the governing mechanisms, it is evident that hydrogen’s effect on mechanical properties in steel is still a controversial topic. This little atom has even by some authors been referred to as the “little devil”. We do not intend to explore this particular description of hydrogen any further. However, we would like to shed some light on the key technical aspects we believe need to be further scrutinized and understood to ensure that the decision-makers have sufficiently reliable data available to decide whether hydrogen gas can be safely transported in new or existing offshore pipelines at an acceptable cost.

scholarly journals Bi-Objective Constraint and Hybrid Optimizer for the Test Case Prioritization

2019 ◽  
Vol 8 (6) ◽  
pp. 3436-3448
Keyword(s):  
Taylor Series ◽  
Optimization Algorithm ◽  
Fitness Function ◽  
Regression Testing ◽  
Test Case ◽  
Test Cases ◽  
Test Case Prioritization ◽  
Optimal Test ◽  
Average Percentage ◽  
Branch Coverage

Regression testing is performed to make conformity that any changes in software program do not disturb the existing characteristics of the software. As the software improves, the test case tends to grow in size that makes it very costly to be executed, and thus the test cases are needed to be prioritized to select the effective test cases for software testing. In this paper, a test case prioritization technique in regression testing is proposed using a novel optimization algorithm known as Taylor series-based Jaya Optimization Algorithm (Taylor-JOA), which is the integration of Taylor series in Jaya Optimization Algorithm (JOA). The optimal test cases are selected based on the fitness function, modelled depending on the constraints, namely fault detection and branch coverage. The experimentation of the proposed Taylor-JOA is performed with the consideration of the evaluation metrics, namely Average Percentage of Fault Detected (APFD) and the Average Percentage of Branch Coverage (APBC). The APFD and the APBC of the proposed Taylor-JOA is 0.995, and 0.9917, respectively, which is high as compared to the existing methods that show the effectiveness of the proposed Taylor-JOA in the task of test case prioritization

Typology of Services

2010 ◽  
pp. 35-85
Author(s):  
Adamantios Koumpis
Keyword(s):  
Supply Chain ◽  
Major Part ◽  
Building Blocks ◽  
Test Case ◽  
Analysis Model ◽  
Service Supply Chain ◽  
Manufacturing Company ◽  
Real Test

Classes and taxonomies of services – how can they be categorized, with respect to different parameters, factors, dimensions. Why some of them matter and some other don’t? How can they be organized to serve specific purposes, etc. The major part of the chapter is justly devoted to the presentation of the Service Analysis Model (SAM). With its four constituent building blocks, SAM provides an insight to the analysis of services and is followed by a section devoted to the synthesis of service and the composition of new ones. The chapter closes with the presentation of a real test case implemented for a manufacturing company to improve their service supply chain.

scholarly journals Polylactide (PLA) and Its Blends with Poly(butylene succinate) (PBS): A Brief Review

Polymers ◽  
2019 ◽  
Vol 11 (7) ◽  
pp. 1193 ◽  
Author(s):  
Shen Su ◽  
Rodion Kopitzky ◽  
Sengül Tolga ◽  
Stephan Kabasci
Keyword(s):  
Material Properties ◽  
Chemical Structure ◽  
Building Blocks ◽  
Processing Parameters ◽  
International Standards ◽  
Butylene Succinate ◽  
Reactive Compatibilization ◽  
Application Potential ◽  
Specific Material

Polylactide (PLA), poly(butylene succinate) (PBS) and blends thereof have been researched in the last two decades due to their commercial availability and the upcoming requirements for using bio-based chemical building blocks. Blends consisting of PLA and PBS offer specific material properties. However, their thermodynamically favored biphasic composition often restricts their applications. Many approaches have been taken to achieve better compatibility for tailored and improved material properties. This review focuses on the modification of PLA/PBS blends in the timeframe from 2007 to early 2019. Firstly, neat polymers of PLA and PBS are introduced in respect of their origin, their chemical structure, thermal and mechanical properties. Secondly, recent studies for improving blend properties are reviewed mainly under the focus of the toughness modification using methods including simple blending, plasticization, reactive compatibilization, and copolymerization. Thirdly, we follow up by reviewing the effect of PBS addition, stereocomplexation, nucleation, and processing parameters on the crystallization of PLA. Next, the biodegradation and disintegration of PLA/PBS blends are summarized regarding the European and International Standards, influencing factors, and degradation mechanisms. Furthermore, the recycling and application potential of the blends are outlined.

Sign in / Sign up

Export Citation Format

Share Document