DIMENSIONING OF ORTHOTROPICALLY STIFFENED CFRP SHELLS OF LARGE LAUNCH VEHICLES FOR LOAD INTRODUCTION AND STABILITY

2010 ◽  
Vol 10 (04) ◽  
pp. 601-621 ◽  
Author(s):  
ANDREAS RITTWEGER ◽  
SUSANNE CHRISTIANSON ◽  
HUBA ÖRY
Keyword(s):  
Analytical Methods ◽  
Flux Distribution ◽  
Fe Analysis ◽  
Launch Vehicles ◽  
Local Instability ◽  
Axial Loads ◽  
Ring Frame ◽  
Final Design ◽  
Shell Equations ◽  
Analytical Approaches

The dimensioning of an orthotropically stiffened cylindrical CFRP shell subjected to the introduction of concentrated axial loads using rapid analytical methods is presented. For stress calculation the shell equations are simplified by applying the semibending theory and integrated by employing the transfer matrix method. Analytical approaches are used for stability verification. The dimensioning considers required constraints in the force flux distribution, strength of the laminate, general instability, panel instability (from ring frame to ring frame) and local instability. The rapid analytical methods allow mass optimization. The final design is confirmed by detailed FE analysis. A comparison of the FE analysis with the analytical results is shown.

scholarly journals Tetraconatan phylogeny with special focus on Malacostraca and Branchiopoda: highlighting the strength of taxon-specific matrices in phylogenomics

2018 ◽  
Vol 285 (1885) ◽  
pp. 20181524 ◽  
Author(s):  
Martin Schwentner ◽  
Stefan Richter ◽  
D. Christopher Rogers ◽  
Gonzalo Giribet
Keyword(s):  
Amino Acid ◽  
Analytical Methods ◽  
Special Focus ◽  
Evolutionary Models ◽  
Phylogenomic Analyses ◽  
New Generation ◽  
Analytical Approaches ◽  
Internal Relationships ◽  
Complete Matrix ◽  
Phylogenomic Study

Understanding the evolution of Tetraconata or Pancrustacea—the clade that includes crustaceans and insects—requires a well-resolved hypothesis regarding the relationships within and among its constituent taxa. Here, we assembled a taxon-rich phylogenomic dataset focusing on crustacean lineages based solely on genomes and new-generation Illumina-generated transcriptomes, including 89 representatives of Tetraconata. This constitutes, to our knowledge, the first phylogenomic study specifically addressing internal relationships of Malacostraca (with 26 species included) and Branchiopoda (36 species). Seven matrices comprising 81–684 orthogroups and 17 690–242 530 amino acid positions were assembled and analysed under five different analytical approaches. To maximize gene occupancy and to improve resolution, taxon-specific matrices were designed for Malacostraca and Branchiopoda. Key tetraconatan taxa (i.e. Oligostraca, Multicrustacea, Branchiopoda, Malacostraca, Thecostraca, Copepoda and Hexapoda) were monophyletic and well supported. Within Branchiopoda, Phyllopoda, Diplostraca, Cladoceromorpha and Cladocera were monophyletic. Within Malacostraca, the clades Eumalacostraca, Decapoda and Reptantia were well supported. Recovery of Caridoida or Peracarida was highly dependent on the analysis for the complete matrix, but it was consistently monophyletic in the malacostracan-specific matrices. From such examples, we demonstrate that taxon-specific matrices and particular evolutionary models and analytical methods, namely CAT-GTR and Dayhoff recoding, outperform other approaches in resolving certain recalcitrant nodes in phylogenomic analyses.

A Comprehensive Study on Burst Pressure Performance of Aluminum Liner for Hydrogen Storage Vessels

2021 ◽  
Vol 143 (4) ◽  
Author(s):  
Serkan Kangal ◽  
A. Harun Sayı ◽  
Ozan Ayakdaş ◽  
Osman Kartav ◽  
Levent Aydın ◽  
...  
Keyword(s):  
Internal Pressure ◽  
Axial Strain ◽  
Cylindrical Part ◽  
Pressure Vessels ◽  
Fe Analysis ◽  
Burst Pressure ◽  
Experimental Investigations ◽  
Fe Model ◽  
Stress Criterion ◽  
Analytical Approaches

Abstract This paper presents a comparative study on the burst pressure performance of aluminum (Al) liner for type-III composite overwrapped pressure vessels (COPVs). In the analysis, the vessels were loaded with increasing internal pressure up to the burst pressure level. In the analytical part of the study, the burst pressure of the cylindrical part was predicted based on the modified von Mises, Tresca, and average shear stress criterion (ASSC). In the numerical analysis, a finite element (FE) model was established in order to predict the behavior of the vessel as a function of increasing internal pressure and determine the final burst. The Al pressure vessels made of Al-6061-T6 alloy with a capacity of 5 L were designed. The manufacturing of the metallic vessels was purchased from a metal forming company. The experimental study was conducted by pressurizing the Al vessels until the burst failure occurred. The radial and axial strain behaviors were monitored at various locations on the vessels during loading. The results obtained through analytical, numerical, and experimental work were compared. The average experimental burst pressure of the vessels was found to be 279 bar. The experimental strain data were compared with the results of the FE analysis. The results indicated that the FE analysis and ASSC-based elastoplastic analytical approaches yielded the best predictions which are within 2.2% of the experimental burst failure values. It was also found that the elastic analysis underestimated the burst failure results; however, it was effective for determining the critical regions over the vessel structure. The strain behavior of the vessels obtained through experimental investigations was well correlated with those predicted through FE analysis.

Design, Analysis and Fabrication of Microflexural NOT Gate

2007 ◽  
Author(s):  
Abhishek Modi ◽  
Prasanna S. Gandhi ◽  
Himani Shah ◽  
Shiv Govind Singh
Keyword(s):  
Logic Gates ◽  
Interesting Property ◽  
Logic Circuits ◽  
Fe Analysis ◽  
Flexure Mechanism ◽  
Working Environments ◽  
Optimal Value ◽  
Final Design ◽  
Term Energy ◽  
Mechanical Logic

Binary logic devices constructed using moving mechanical components at microscale can be useful in harsh working environments where their electronic counterparts would fail. This paper demonstrates a novel design, extensive analysis, and development method of a micromechanical NOT gate and analyzes important issues in further development of mechanical logic circuits. The proposed NOT gate uses parallelogram flexures and flexure beam hinges to realize the logic without effects of friction. Extensive finite element (FE) analysis, carried out using ANSYS, enables us to arrive at the final design dimensions. We introduce a new term “Energy Transmission Ratio (ETR)” specific to flexure mechanism-based transmission systems and further FE analysis brings out interesting property that ETR has an optimal value for given flexure geometry. This result can be useful while connecting several logic gates to develop mechanical logic circuits. A graphical procedure for analysis of such connections is outlined based on our FE results. Finally, the proposed NOT gate is fabricated with SU-8 and demonstrated working successfully.

Analytical Methods to Evaluate Flux Distributions From Point-Focus Collectors for Solar Furnace and Dish Engine Applications

2010 ◽  
Author(s):  
Clifford K. Ho ◽  
Siri S. Khalsa ◽  
Nathan P. Siegel
Keyword(s):  
Analytical Methods ◽  
Maximum Concentration ◽  
Concentration Ratio ◽  
Flux Distribution ◽  
Focal Length ◽  
Solar Furnace ◽  
Analytical Function

This paper introduces a new analytical “stretch” function that accurately predicts the flux distribution from on-axis point-focus collectors. Different dish sizes and slope errors can be assessed using this analytical function with a ratio of the focal length to collector diameter fixed at 0.6 to yield the maximum concentration ratio. Results are compared to data, and the stretch function is shown to provide more accurate flux distributions than other analytical methods employing cone optics.

scholarly journals The Composer's Hand: An Analysis of Selected String Orchestral Works by Arvo Pärt

2021 ◽  
Author(s):  
◽  
Mark Johnson
Keyword(s):  
Analytical Methods ◽  
Analytical Techniques ◽  
Compositional Process ◽  
Aesthetic Value ◽  
Orchestral Works ◽  
Process Music ◽  
The Aesthetic ◽  
Traditional Approaches ◽  
Compositional System ◽  
Analytical Approaches

<p>Arvo Pärt’s music has received little attention from theoretical scholars, in part, because it is often labelled as minimalist or process music. This is due primarily to his use of limited sets of musical materials and predetermined repetitive melodic and rhythmic procedures. In this sense, it is implied that authorial decisions play little role in the compositional process of his music. In addition, the confluences of multiple M-voice/T-voice pairings, which create a rich array of harmonically non-functional chord progressions, do not lend themselves to traditional approaches to musical analysis, thus acting as a further deterrent to analysts and theorists.  This investigation postulates that the presence of the ‘composer’s hand’ is much more significant in Pärt’s music than has been previously realised by those who label his music as minimalist or process music; and by engaging in a multimodal methodology, this thesis demonstrates that Pärt’s music does, in fact, respond to post-tonal analytical approaches. It also shows that a non-traditional application of post-tonal analytical techniques can yield valuable and productive insights into Pärt’s compositional system, and that there is actually much for theorists and analysts to discover in his music.  The approach to the investigation is based on drawing from and combining several post-tonal analytical methods, any one of which would be insufficient on its own, given the uniqueness of Pärt’s sound world and the fact that such approaches have been developed to enlighten very different repertoires. The methodology incorporates the following post-tonal analytical methods: descriptions of the ‘musical fabric’ of each work; a detailed analysis of how each composition appears to have been constructed; new approaches to visualising the relationships between the pitch classes of particular works; and mappings of each work’s pitch-class and interval-vector content.  This investigation demonstrates, through multimodal analysis of six selected string orchestral works by the composer, that hidden beneath the seemingly ‘minimal’ surface layers of Pärt’s music are carefully crafted musical constructions that result from intersecting procedures and multifaceted rules, as well as what appear to be intentional exceptions to those rules – thus revealing the composer’s hand. An awareness of these hidden constructions and the careful craftsmanship that went into their creation can provide the informed listener with the critical foundation from which the aesthetic value of Pärt’s music can be assessed and appreciated.</p>

scholarly journals Analytical methods in herpesvirus genomics

2014 ◽  
Vol 7 (2) ◽  
pp. 109-118
Author(s):  
Jana Blaškovičová ◽  
Ján Labuda
Keyword(s):  
Analytical Methods ◽  
Genome Structure ◽  
Human Herpesvirus ◽  
B Cell Lymphoma ◽  
Varicella Zoster ◽  
Barr Virus ◽  
Epstein Barr ◽  
Simplex Virus ◽  
And Function ◽  
Analytical Approaches

Abstract Genomics is a branch of bioanalytical chemistry characterized as the study of the genome structure and function. Genome represents the complete set of chromosomal and extrachromosomal genes of an organism, a cell, an organelle or a virus. There are at least five from eight species of herpesviruses commonly widespread among humans, Herpes simplex virus type 1 and 2, Varicella zoster virus, Epstein-Barr virus and Cytomegalovirus. Human gammaherpesviruses can cause serious diseases including B-cell lymphoma and Kaposi’s sarcoma. Diagnostics and study of the herpesviruses is directly dependent on the development of modern analytical methods able to detect and determine the presence and evolution of herpesviral particles/ genomes. Diagnostics and genomic characterization of human herpesvirus species is based on bioanalytical methods such as polymerase chain reaction (PCR), DNA sequencing, gel electrophoresis, blotting and others. The progress in analytical approaches in the herpesvirus genomics is reviewed in this article.

Analytical Approaches to Verify Food Integrity: Needs and Challenges

2016 ◽  
Vol 99 (5) ◽  
pp. 1135-1144 ◽  
Author(s):  
Richard H Stadler ◽  
Lien-Anh Tran ◽  
Christophe Cavin ◽  
Pascal Zbinden ◽  
Erik J M Konings
Keyword(s):  
Supply Chain ◽  
Food Supply ◽  
Analytical Methods ◽  
Raw Materials ◽  
Control Measures ◽  
Food Supply Chain ◽  
Food Fraud ◽  
Global Consensus ◽  
The Individual ◽  
Analytical Approaches

Abstract A brief overview of the main analytical approaches and practices to determine food authenticity is presented, addressing, as well, food supply chain and future requirements to more effectively mitigate food fraud. Food companies are introducing procedures and mechanisms that allow them to identify vulnerabilities in their food supply chain under the umbrella of a food fraud prevention management system. A key step and first line of defense is thorough supply chain mapping and full transparency, assessing the likelihood of fraudsters to penetrate the chain at any point. More vulnerable chains, such as those where ingredients and/or raw materials are purchased through traders or auctions, may require a higher degree of sampling, testing, and surveillance. Access to analytical tools is therefore pivotal, requiring continuous development and possibly sophistication in identifying chemical markers, data acquisition, and modeling. Significant progress in portable technologies is evident already today, for instance, as in the rapid testing now available at the agricultural level. In the near future, consumers may also have the ability to scan products in stores or at home to authenticate labels and food content. For food manufacturers, targeted analytical methods complemented by untargeted approaches are end control measures at the factory gate when the material is delivered. In essence, testing for food adulterants is an integral part of routine QC, ideally tailored to the risks in the individual markets and/or geographies or supply chains. The development of analytical methods is a first step in verifying the compliance and authenticity of food materials. A next, more challenging step is the successful establishment of global consensus reference methods as exemplified by the AOAC Stakeholder Panel on Infant Formula and Adult Nutritionals initiative, which can serve as an approach that could also be applied to methods for contaminants and adulterants in food. The food industry has taken these many challenges aboard, working closely with all stakeholders and continuously communicating on progress in a fully transparent manner.

scholarly journals Approximate Series Solutions for Nonlinear Free Vibration of Suspended Cables

2014 ◽  
Vol 2014 ◽  
pp. 1-12 ◽  
Author(s):  
Yaobing Zhao ◽  
Ceshi Sun ◽  
Zhiqian Wang ◽  
Lianhua Wang
Keyword(s):  
Free Vibration ◽  
Analytical Methods ◽  
Initial Conditions ◽  
Detailed Comparison ◽  
Dynamic Responses ◽  
Mode Shapes ◽  
Series Solutions ◽  
Nonlinear Free Vibration ◽  
Suspended Cables ◽  
Analytical Approaches

This paper presents approximate series solutions for nonlinear free vibration of suspended cables via the Lindstedt-Poincare method and homotopy analysis method, respectively. Firstly, taking into account the geometric nonlinearity of the suspended cable as well as the quasi-static assumption, a mathematical model is presented. Secondly, two analytical methods are introduced to obtain the approximate series solutions in the case of nonlinear free vibration. Moreover, small and large sag-to-span ratios and initial conditions are chosen to study the nonlinear dynamic responses by these two analytical methods. The numerical results indicate that frequency amplitude relationships obtained with different analytical approaches exhibit some quantitative and qualitative differences in the cases of motions, mode shapes, and particular sag-to-span ratios. Finally, a detailed comparison of the differences in the displacement fields and cable axial total tensions is made.

Analytical, FEA and Experimental Methods for Computing the Resilience of Tapped Thread Joints

2011 ◽  
Author(s):  
Yosef Amir ◽  
John Reif ◽  
Nicholas Konkle
Keyword(s):  
Analytical Model ◽  
Analytical Methods ◽  
Dissimilar Materials ◽  
Experimental Methods ◽  
Bolted Joint ◽  
Element Analysis ◽  
Fea Modeling ◽  
Screw Joint ◽  
Basic Parameters ◽  
Analytical Approaches

Bolted joint behavior is based on many parameters, many of which are not well known or understood. The basic parameters describing the signature behavior of the bolted joint are the fastener and clamped joint flanges’ resilience. The level of confidence in the resilience parameter defines the confidence level of further analysis performed throughout the design phase. For general cases with simple configurations of the bolt and joint members, well-known analytical methods such as VDI 2230 satisfy the purpose of bolted joint analyses. However, in practice there are cases which deviate from the idealized joint, such as complex bolted joint geometry or dissimilar materials which cannot be simplified for an analytical model. The particular case studied here is that of a screw joint or tapped thread joint (TTJ) where the analytical model is ambiguous. In addition, for TTJs that are critical to safety a high confidence in the result is desired, so finite element analysis (FEA) or experimental methods are preferred to assess the resilience of the clamped and tapped flanges. This paper presents FEA modeling as well as analytical methods for complex joints, particularly for TTJ configurations. Resilience values for FEA and analytical approaches are presented, as well as experimental results for validation.

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