Omnidirectional Full-Field Displacement Reconstruction Method for Complex Three-Dimensional Structures

AIAA Journal ◽  
2020 ◽  
Vol 58 (7) ◽  
pp. 3174-3186
Author(s):  
Xiao-Hang Jiang ◽  
Xiao-Jun Wang ◽  
Kai-Hua Yuan ◽  
Bo-Wen Ni ◽  
Zi-Liang Wang
Keyword(s):  
Three Dimensional ◽  
Reconstruction Method ◽  
Full Field ◽  
Field Displacement ◽  
Displacement Reconstruction

scholarly journals Full-field deformation characteristics of anisotropic marble under compression revealed by 3D digital image correlation

2021 ◽  
Author(s):  
yu wang ◽  
zhengyang song ◽  
zhiqiang hou ◽  
chun zhu
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Progressive Failure ◽  
Three Dimensional ◽  
Image Correlation ◽  
Localized Deformation ◽  
Full Field ◽  
Strain Pattern ◽  
Field Displacement ◽  
3D Digital Image Correlation

This work aims to reveal the anisotropic full-field displacemnet and the progressive failure behaviors of interbedded marble under uniaxial compression using three dimensional digital image correlation (3D DIC) technique. The effects of the interbed orientation on the field displacement and strain pattern and the crack evolution were analyzed qualitatively and quantitatively. Testing results show that different stress strain responses can be generated depending on the interbed orientation, and the interbeds influence the localized deformation and high strain concentration pattern. The field displacement evolution curves present different pattern and are impacted by the localized deformation. In addition, the strain localization takes places progressively and develops at a lower rate for rock with 0° and 90° interbed than those of 30° and 60° interbed rock. The quick shear-sliding along the interbed leads to the minimum strength of rock having 30° interbed orientation. It is suggested that rock anisotropic field deformation is structure depended.

Cornea Full-field Displacement and Strain Measurement in Vivo Using Three-dimensional Digital Image Correlation

2018 ◽  
Vol 95 (11) ◽  
pp. 1027-1034 ◽  
Author(s):  
Xueyong Zhang ◽  
Qing Wang ◽  
Like Wang ◽  
Hong Xiao ◽  
Daming Zhang ◽  
...  
Keyword(s):  
Digital Image Correlation ◽  
Digital Image ◽  
Strain Measurement ◽  
Three Dimensional ◽  
Image Correlation ◽  
Full Field ◽  
Field Displacement

Three-dimensional reconstruction of the 40S ribosomal subunit from rabbit reticulocytes

1987 ◽  
Vol 45 ◽  
pp. 936-937
Author(s):  
Neng-Yu Zhang ◽  
Terence Wagenknecht ◽  
Michael Radermacher ◽  
Tom Obrig ◽  
Joachim Frank
Keyword(s):  
Three Dimensional ◽  
Ribosomal Subunit ◽  
Uranyl Acetate ◽  
Reconstruction Method ◽  
Single Exposure ◽  
Electron Dose ◽  
Ribosomal Subunits ◽  
40S Ribosomal Subunit ◽  
Dimensional Reconstruction ◽  
Rabbit Reticulocytes

We have reconstructed the 40S ribosomal subunit at a resolution of 4 nm using the single-exposure pseudo-conical reconstruction method of Radermacher et al.Small (40S) ribosomal subunits were Isolated from rabbit reticulocytes, applied to grids and negatively stained (0.5% uranyl acetate) in a manner that “sandwiches” the specimen between two layers of carbon. Regions of the grid exhibiting uniform and thick staining were identified and photographed twice (magnification 49,000X). The first micrograph was always taken with the specimen tilted by 50° and the second was of the Identical area untilted (Fig. 1). For each of the micrographs the specimen was subjected to an electron dose of 2000-3000 el/nm2.Three hundred thirty particles appearing in the L view (defined in [4]) were selected from both tilted- and untilted-specimen micrographs. The untilted particles were aligned and their rotational alignment produced the azimuthal angles of the tilted particles in the conical tilt series.

scholarly journals Automatic Reconstruction of Multi-Level Indoor Spaces from Point Cloud and Trajectory

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3493
Author(s):  
Gahyeon Lim ◽  
Nakju Doh
Keyword(s):  
Point Cloud ◽  
Dimensional Space ◽  
Three Dimensional ◽  
Reconstruction Method ◽  
Complex Environments ◽  
Indoor Space ◽  
Multi Level ◽  
Level Building ◽  
Indoor Spaces ◽  
Data Term

Remarkable progress in the development of modeling methods for indoor spaces has been made in recent years with a focus on the reconstruction of complex environments, such as multi-room and multi-level buildings. Existing methods represent indoor structure models as a combination of several sub-spaces, which are constructed by room segmentation or horizontal slicing approach that divide the multi-room or multi-level building environments into several segments. In this study, we propose an automatic reconstruction method of multi-level indoor spaces with unique models, including inter-room and inter-floor connections from point cloud and trajectory. We construct structural points from registered point cloud and extract piece-wise planar segments from the structural points. Then, a three-dimensional space decomposition is conducted and water-tight meshes are generated with energy minimization using graph cut algorithm. The data term of the energy function is expressed as a difference in visibility between each decomposed space and trajectory. The proposed method allows modeling of indoor spaces in complex environments, such as multi-room, room-less, and multi-level buildings. The performance of the proposed approach is evaluated for seven indoor space datasets.

Acceleration of the EM-like reconstruction method for diffuse optical tomography with ordered-subsets method

2014 ◽  
Vol 22 (3) ◽  
Author(s):  
Caifang Wang
Keyword(s):  
Numerical Experiments ◽  
Imaging Modality ◽  
Random Medium ◽  
Optical Tomography ◽  
Back Propagation ◽  
Three Dimensional ◽  
Diffuse Optical Tomography ◽  
Optical Parameters ◽  
Reconstruction Method ◽  
Boundary Measurements

Abstract.Diffuse optical tomography (DOT) is an optical imaging modality, which provides the spatial distribution of the optical parameters inside a random medium. A propagation back-propagation method named EM-like reconstruction method for stationary DOT problem has been proposed yet. This method is really time consuming. Hence the ordered-subsets (OS) technique for this reconstruction method is studied in this paper. The boundary measurements of DOT are grouped into nonoverlapping and overlapping ordered sequence of subsets with random partition, sequential partition and periodic partition, respectively. The performance of OS methods is compared with the standard EM-like reconstruction method with two-dimensional and three-dimensional numerical experiments. The numerical experiments indicate that reconstruction of nonoverlapping subsets with periodic partition, overlapping subsets with periodic partition and standard EM-like method provide very similar acceptable reconstruction results. However, reconstruction of nonoverlapping subsets with periodic partition spends a minimum of time to get proper results.

Computational Investigation of Thrust Production of a Dolphin at Various Swimming Speeds

2021 ◽  
Author(s):  
Junshi Wang ◽  
Vadim Pavlov ◽  
Zhipeng Lou ◽  
Haibo Dong
Keyword(s):  
Surface Pressure ◽  
Swimming Performance ◽  
Three Dimensional ◽  
Numerical Approach ◽  
Immersed Boundary ◽  
Reconstruction Method ◽  
Force Coefficient ◽  
Speed Increase ◽  
Generation Mechanisms ◽  
Thrust Production

Abstract Dolphins are known for their outstanding swimming performance. However, the difference in flow physics at different speeds remains elusive. In this work, the underlying mechanisms of dolphin swimming at three speeds, 2 m/s, 5 m/s, and 8 m/s, are explored using a combined experimental and numerical approach. Using the scanned CAD model of the Atlantic white-sided dolphin (Lagenorhynchus acutus) and virtual skeleton-based surface reconstruction method, a three-dimensional high-fidelity computational model is obtained with time-varying kinematics. A sharp-interface immersed-boundary-method (IBM) based direct numerical simulation (DNS) solver is employed to calculate the corresponding thrust production, wake structure, and surface pressure at different swimming speeds. It is found that the fluke keeps its effective angle of attack at high values for about 60% of each stroke. The total pressure force coefficient along the x-axis converges as the speed increase. The flow and surface pressure analysis both show considerable differences between lower (2 m/s) and higher (5 m/s and 8 m/s) speeds. The results from this work help to bring new insight into understanding the force generation mechanisms of the highly efficient dolphin swimming and offer potential suggestions to the future designs of unmanned underwater vehicles.

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