Advanced Aluminium and Hybrid Aerostructures for Future Aircraft

2006 ◽  
Vol 519-521 ◽  
pp. 1233-1238 ◽  
Author(s):  
John Liu
Keyword(s):  
Large Scale ◽  
High Strength ◽  
Hybrid Structures ◽  
Structural Performance ◽  
High Toughness ◽  
Future Performance ◽  
Structural Assembly ◽  
Scale Test ◽  
Fundamental Shift

Alcoa has made a fundamental shift in its aerospace R&D program, broadening its scientific and engineering portfolio by creating an integrated, strategic, long-term initiative. The ultimate goal is to help re-define the future performance, cost and value of the metallic and hybrid aerostructures that the company feels will be required to meet the mission requirements of tomorrow’s aircraft. Having intensely studied various structural options, Alcoa believes Hybrid Structural Assembly optimized with a combination of Advanced Aluminum and Hybrid Components offer the best opportunities to maximize structural performance. Not only do the new alloys, notably 3rd Generation Al-Li alloys and high strength and high toughness 7xxx alloys provide structural performance enhancements, they also offer dramatic improvements in corrosion resistance. In this paper, several advanced alloys and structural concepts targeted for next generation wing and fuselage applications and large scale test article results supporting Alcoa’s optimism for Advanced Metallic and Hybrid Structures are reviewed.

scholarly journals Collective Emotions and Social Resilience in the Digital Traces After a Terrorist Attack

2019 ◽  
Vol 30 (4) ◽  
pp. 617-628 ◽  
Author(s):  
David Garcia ◽  
Bernard Rimé
Keyword(s):  
Large Scale ◽  
Terrorist Attack ◽  
Terrorist Attacks ◽  
Social Resilience ◽  
Collective Emotions ◽  
The Social ◽  
Collective Effervescence ◽  
Scale Test ◽  
Twitter Users

After collective traumas such as natural disasters and terrorist attacks, members of concerned communities experience intense emotions and talk profusely about them. Although these exchanges resemble simple emotional venting, Durkheim’s theory of collective effervescence postulates that these collective emotions lead to higher levels of solidarity in the affected community. We present the first large-scale test of this theory through the analysis of digital traces of 62,114 Twitter users after the Paris terrorist attacks of November 2015. We found a collective negative emotional response followed by a marked long-term increase in the use of lexical indicators related to solidarity. Expressions of social processes, prosocial behavior, and positive affect were higher in the months after the attacks for the individuals who participated to a higher degree in the collective emotion. Our findings support the conclusion that collective emotions after a disaster are associated with higher solidarity, revealing the social resilience of a community.

Critical Review and Appraisal of Traditional and New Procedures for the Quantification of Creep Fracture Behavior Using 1Cr–1Mo–0.25V Steel

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
M. Evans
Keyword(s):  
Large Scale ◽  
Rupture Life ◽  
Design Data ◽  
Data Set ◽  
New Approach ◽  
Creep Fracture ◽  
Scale Test ◽  
New Procedures ◽  
Term Data

The approaches traditionally used to quantify creep and creep fracture are critically assessed and reviewed in relation to a new approach proposed by Wilshire and Scharning. The characteristics, limitations, and predictive accuracies of these models are illustrated by reference to information openly available for the bainitic 1Cr–1Mo–0.25V steel. When applied to this comprehensive long-term data set, the estimated 100,000–300,000 h strength obtained from the older so called traditional methods varied considerably. Further, the isothermal predictions from these models became very unstable beyond 100,000 h. In contrast, normalizing the applied stress through an appropriate ultimate tensile strength value not only reduced the melt to melt scatter in rupture life, but also the 100,000 h strengths determined from this model for this large scale test program are predicted very accurately by extrapolation of creep life measurements lasting less than 5000 h. The approach therefore offers the potential for reducing the scale and cost of current procedures for acquisition of long-term engineering design data.

scholarly journals Collective Emotions and Social Resilience in the Digital Traces After a Terrorist Attack

2018 ◽  
Author(s):  
David Garcia ◽  
Bernard Rime
Keyword(s):  
Large Scale ◽  
Terrorist Attack ◽  
Terrorist Attacks ◽  
Social Resilience ◽  
Collective Emotions ◽  
The Social ◽  
Collective Effervescence ◽  
Scale Test ◽  
Twitter Users

After collective traumas such as natural disasters and terrorist attacks, members of concerned communities experience intense emotions and talk profusely about them. Although these exchanges resemble simple emotional venting, Durkheim’s theory of collective effervescence postulates that these collective emotions lead to higher levels of solidarity in the affected community. We present the first large-scale test of this theory through the analysis of digital traces of 62,114 Twitter users after the Paris terrorist attacks of November 2015. We found a collective negative emotional response followed by a marked long-term increase in the use of lexical indicators related to solidarity. Expressions of social processes, prosocial behavior, and positive affect were higher in the months after the attacks for the individuals who participated to a higher degree in the collective emotion. Our findings support the conclusion that collective emotions after a disaster are associated with higher solidarity, revealing the social resilience of a community.

Numerical Modelling of the Experimental Response of SRG Systems

2019 ◽  
Vol 817 ◽  
pp. 37-43
Author(s):  
Marialaura Malena ◽  
Marialuigia Sangirardi ◽  
Francesca Roscini ◽  
Gianmarco de Felice
Keyword(s):  
Numerical Modelling ◽  
Large Scale ◽  
Numerical Models ◽  
High Strength ◽  
Experimental Tests ◽  
Tensile Tests ◽  
Technical Committee ◽  
Structural Performance ◽  
Rilem Technical Committee ◽  
Test Procedures

Modern repairing and retrofitting methods for existing structures make use of composite materials, consisting of high strength textiles and a matrix, which can be either polymeric or inorganic. These kinds of techniques have been largely applied to masonry structures, since they significantly improve structural performance with a small increase of weight and a minimum invasiveness. However, the application of organic gluing agents on masonry has revealed some well-known drawbacks, which are almost all overcome resorting to inorganic matrixes, namely cement or lime mortars. An entire class of composites is thus identified as TRM (Textile Reinforced Mortars) or FRCM (Fibre Reinforced Cementitious Matrices). Among them, Steel Reinforced Grout (SRG) are characterized by Ultra High Tensile Strength Steel (UHTSS) cords embedded in mortar matrix and their use to improve the structural performance of existing historical masonry buildings is becoming more and more diffused. Qualification tests and acceptance criteria for SRG have just been defined. Nonetheless, numerical simulation of current available test procedures is mandatory to identify peculiar aspects of the response that at a following stage become an integral part of large scale models, when entire reinforced structures or portions need to be analysed. To this end, this work presents the numerical modelling of two different direct tensile tests on SRG systems: the Clamping-grip setup (RILEM Technical Committee 232-TDT 2016) and the Clevis-grip setup (ICC-ES AC434 2016). Numerical models able to replicate experimental tests and catch fundamental differences in their failure mechanisms are present

Analysis of long-term mechanical grooming on large-scale test panels coated with an antifouling and a fouling-release coating

Biofouling ◽  
2015 ◽  
Vol 31 (8) ◽  
pp. 625-638 ◽  
Author(s):  
John Hearin ◽  
Kelli Z. Hunsucker ◽  
Geoffrey Swain ◽  
Abraham Stephens ◽  
Harrison Gardner ◽  
...  
Keyword(s):  
Large Scale ◽  
Fouling Release ◽  
Scale Test

Evolution of Large-Scale Coronal Structures

1994 ◽  
Vol 144 ◽  
pp. 29-33
Author(s):  
P. Ambrož
Keyword(s):  
Magnetic Field ◽  
Field Line ◽  
Large Scale ◽  
Coronal Magnetic Field ◽  
Source Surface ◽  
Solar Cycles ◽  
Characteristic Relationship ◽  
The Magnetic Field ◽  
Coronal Structures

AbstractThe large-scale coronal structures observed during the sporadically visible solar eclipses were compared with the numerically extrapolated field-line structures of coronal magnetic field. A characteristic relationship between the observed structures of coronal plasma and the magnetic field line configurations was determined. The long-term evolution of large scale coronal structures inferred from photospheric magnetic observations in the course of 11- and 22-year solar cycles is described.Some known parameters, such as the source surface radius, or coronal rotation rate are discussed and actually interpreted. A relation between the large-scale photospheric magnetic field evolution and the coronal structure rearrangement is demonstrated.

Computer Analyses in Preventive Health Research

1967 ◽  
Vol 06 (01) ◽  
pp. 8-14 ◽  
Author(s):  
M. F. Collen
Keyword(s):  
Medical Research ◽  
Preventive Medicine ◽  
Health Research ◽  
Large Scale ◽  
Preventive Health ◽  
New Era ◽  
Large Numbers ◽  
Normal Test ◽  
Computer Analyses

The utilization of an automated multitest laboratory as a data acquisition center and of a computer for trie data processing and analysis permits large scale preventive medical research previously not feasible. Normal test values are easily generated for the particular population studied. Long-term epidemiological research on large numbers of persons becomes practical. It is our belief that the advent of automation and computers has introduced a new era of preventive medicine.

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