Modal learning displacement–strain transformation

2019 ◽  
Vol 90 (7) ◽  
pp. 075113 ◽  
Author(s):  
Huaxia Deng ◽  
Haicong Zhang ◽  
Jun Wang ◽  
Jin Zhang ◽  
Mengchao Ma ◽  
...  
1982 ◽  
Vol 49 (2) ◽  
pp. 353-360 ◽  
Author(s):  
H. C. Yang ◽  
Y. T. Chou

This paper deals with a generalized plane problem in which a uniform stress-free strain transformation takes place in the region of an elliptic cyclinder (the inclusion) oriented in the 〈111〉 direction in an anisotropic solid of cubic symmetry. Closed-form solutions for the elastic fields and the strain energies are presented. The perturbation of an otherwise uniform stress field due to a 〈111〉 elliptic inhomogeneity is also treated including two extreme cases, elliptic cavities and rigid inhomogeneities.


2020 ◽  
Vol 16 (1) ◽  
Author(s):  
Keisuke Otsuka ◽  
Yinan Wang ◽  
Kanjuro Makihara

Abstract High aspect ratio wings are potential candidates for use in atmospheric satellites and civil aircraft as they exhibit a low induced drag, which can reduce the fuel consumption. Owing to their slender and light weight configuration, such wings undergo highly flexible aeroelastic static and dynamic deformations that cannot be analyzed using conventional linear analysis methods. An aeroelastic analysis framework based on the absolute nodal coordinate formulation (ANCF) can be used to analyze the static and dynamic deformations of high aspect ratio wings. However, owing to the highly nonlinear elastic force, the statically deformed wing shape during steady flight cannot be efficiently obtained via static analyses. Therefore, an ANCF with a vector-strain transformation (ANCF-VST) was proposed in this work. Considering the slender geometry of high aspect ratio wings, the nodal vectors of an ANCF beam element were transformed to the strains. In this manner, a constant stiffness matrix and reduced degrees-of-freedom could be generated while capturing the highly flexible deformations accurately. The ANCF-VST exhibited superior convergence performance and accuracy compared to those of analytical approaches and other nonlinear beam formulations. Moreover, an aeroelastic analysis flow coupling the ANCF-VST and an aerodynamic model based on the unsteady vortex lattice method was proposed to perform the static and dynamic analyses successively. The proposed and existing aeroelastic frameworks exhibited a good agreement in the analyses, which demonstrated the feasibility of employing the proposed framework to analyze high aspect ratio wings.


2004 ◽  
Vol 70 (12) ◽  
pp. 7018-7023 ◽  
Author(s):  
Eduardo Cebollero ◽  
Ramon Gonzalez

ABSTRACT Genetic improvement of industrial yeast strains is restricted by the availability of selectable transformation markers. Antibiotic resistance markers have to be avoided for public health reasons, while auxotrophy markers are generally not useful for wine yeast strain transformation because most industrial Saccharomyces cerevisiae strains are prototrophic. For this work, we performed a comparative study of the usefulness of two alternative dominant selectable markers in both episomic and centromeric plasmids. Even though the selection for sulfite resistance conferred by FZF1-4 resulted in a larger number of transformants for a laboratory strain, the p-fluoro-dl-phenylalanine resistance conferred by ARO4-OFP resulted in a more suitable selection marker for all industrial strains tested. Both episomic and centromeric constructions carrying this marker resulted in transformation frequencies close to or above 103 transformants per μg of DNA for the three wine yeast strains tested.


2014 ◽  
Vol 60 ◽  
pp. 100-103
Author(s):  
Z.X. Jiang ◽  
Y. Zhang ◽  
H.H. Huang ◽  
X.S. Liu ◽  
C.L. Yuan ◽  
...  

2015 ◽  
Vol 3 (4) ◽  
pp. SAA133-SAA160 ◽  
Author(s):  
Steven Lingrey ◽  
Oskar Vidal-Royo

The use of structural restorations as a tool to investigate structural evolution, fault and horizon relationships, and validity of interpretation has been widespread for more than four decades. The first efforts relied on hand-drafted bed-length measurements of commonly constant thickness stratigraphic units and were typically applied to fold-and-thrust belt settings. The advent of computer-assisted section construction and restoration software allowed for the assessment of more complicated structural interpretations by applying several new methods for forward and inverse strain transformation. Although quicker and more accurate than hand-drafted, the results of computer-aided structural modeling still need to be interrogated. We have reviewed the different strain transformation (restoration) methods available and their implications for bed length and area conservation: (1) fundamental simple shear and its two basic modes (flexural slip and inclined shear inversions), (2) fault-related folding techniques, and (3) the effects of mechanical stratigraphy and compaction. The assessment of the restoration methods was illustrated by examining two examples: the Mount Crandell Duplex Structure in southern Alberta and the Virgin River Extensional Basin in the southeast of Nevada. For both examples, we developed tables listing and confirming the deformed/restored state line lengths and areas. We believe that such tables should be provided for any strain transformation exercise, along with the restoration results as parameters for quality control, to prevent over- and underestimations that deviate more than 5% from the initial interpretation.


Genes ◽  
2019 ◽  
Vol 10 (9) ◽  
pp. 707 ◽  
Author(s):  
Min Jung Kwun ◽  
Marco R. Oggioni ◽  
Stephen D. Bentley ◽  
Christophe Fraser ◽  
Nicholas J. Croucher

A diverse set of mobile genetic elements (MGEs) transmit between Streptococcus pneumoniae cells, but many isolates remain uninfected. The best-characterised defences against horizontal transmission of MGEs are restriction-modification systems (RMSs), of which there are two phase-variable examples in S. pneumoniae. Additionally, the transformation machinery has been proposed to limit vertical transmission of chromosomally integrated MGEs. This work describes how these mechanisms can act in concert. Experimental data demonstrate RMS phase variation occurs at a sub-maximal rate. Simulations suggest this may be optimal if MGEs are sometimes vertically inherited, as it reduces the probability that an infected cell will switch between RMS variants while the MGE is invading the population, and thereby undermine the restriction barrier. Such vertically inherited MGEs can be deleted by transformation. The lack of between-strain transformation hotspots at known prophage att sites suggests transformation cannot remove an MGE from a strain in which it is fixed. However, simulations confirmed that transformation was nevertheless effective at preventing the spread of MGEs into a previously uninfected cell population, if a recombination barrier existed between co-colonising strains. Further simulations combining these effects of phase variable RMSs and transformation found they synergistically inhibited MGEs spreading, through limiting both vertical and horizontal transmission.


2009 ◽  
Author(s):  
Thomas Rödig ◽  
Andreas Schönecker ◽  
Lutz Seffner ◽  
Welf-Guntram Drossel ◽  
Holger Kunze ◽  
...  

Author(s):  
Jakerson R. Gevinski ◽  
Robson Pederiva

The identification of strain critical regions on machinery and equipment, under operating conditions, can be accomplished by knowing the operating strain modes. Operating strain modes are interpreted as a dynamic strain distribution of the structure at a specific time or frequency. Strain measurements are conventionally obtained by strain gauge techniques. However, strain measurements with conventional strain gauges are not always possible, and the gauges are not reusable and cannot be moved from point to point when they have been attached to structures. In this paper, a post-processing technique based on Operating Deflection Shapes (ODS) is evaluated with an experimental test. Operational strain modes of an aluminum plate were identified from accelerations measured using tri-axial accelerometer. The operating modes were analyzed at frequencies close to the plate’s natural frequency, previously known by numerical simulation, in the frequency range 0–1000 Hz. The plate was excited with random white noise signal. We used the finite element method in the displacement to strain transformation. Operational modes were compared with simulated modes, which were obtained by modal superposition. The comparisons showed consistency between experimentally and numerically identified modes. Regions of greatest strain could be identified graphically in the color map regarding the minimum and maximum strain.


2013 ◽  
Vol 47 (7) ◽  
pp. 601-604 ◽  
Author(s):  
N. M. Volodin ◽  
Yu. N. Mishin ◽  
V. V. Kaminskii ◽  
Yu. V. Zakharov

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