Articles de revues sur le sujet « 3D displacement »
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1
Hu, Jun, Jianwen Shi, Jihong Liu, Wanji Zheng et Kang Zhu. « Calculating Co-Seismic Three-Dimensional Displacements from InSAR Observations with the Dislocation Model-Based Displacement Direction Constraint : Application to the 23 July 2020 Mw6.3 Nima Earthquake, China ». Remote Sensing 14, no 18 (8 septembre 2022) : 4481. http://dx.doi.org/10.3390/rs14184481.
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As one of the most prevailing geodetic tools, the interferometric synthetic aperture radar (InSAR) technique can accurately obtain co-seismic displacements, but is limited to the one-dimensional line-of-sight (LOS) measurement. It is therefore difficult to completely reveal the real three-dimensional (3D) surface displacements with InSAR. By employing azimuth displacement observations from pixel offset tracking (POT) and multiple aperture InSAR (MAI) techniques, 3D displacements of large-magnitude earthquakes can be obtained by integrating the ascending and descending data. However, this method cannot be used to accurately realize the 3D surface displacement measurements of small-magnitude earthquakes due to the low accuracies of the POT/MAI-derived azimuth displacement measurements. In this paper, an alternative method is proposed to calculate co-seismic 3D displacements from ascending and descending InSAR-LOS observations with the dislocation model-based displacement direction constraint. The main contribution lies in the two virtual observation equations that are obtained from the dislocation model-based forward-modeling 3D displacements, which are then combined with the ascending/descending InSAR observations to calculate the 3D displacements. The basis of the two virtual observation equations is that the directions of the 3D displacement vectors are very similar for real and model-based 3D displacements. In addition, the weighted least squares (WLS) method is employed to solve the final 3D displacements, which aims to consider and balance the possible errors in the InSAR observations as well as the dislocation model-based displacement direction constraint. A simulation experiment demonstrates that the proposed method can achieve more accurate 3D displacements compared with the existing methods. The co-seismic 3D displacements of the 2020 Nima earthquake are then accurately obtained by the proposed method. The results show that co-seismic displacements are dominated by the vertical displacement, the magnitude of the horizontal displacement is relatively small, and the overall displacement pattern fits well with the tensile rupture.
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Milosevic, Milos, Nenad Mitrovic, Vesna Miletić, Uroš Tatic et Andrea Ezdenci. « Analysis of Composite Shrinkage Stresses on 3D Premolar Models with Different Cavity Design Using Finite Element Method ». Key Engineering Materials 586 (septembre 2013) : 202–5. http://dx.doi.org/10.4028/www.scientific.net/kem.586.202.
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Local polymerization stress occurs due to polymerization shrinkage of resin based composites adhesively bonded to tooth tissues. Shrinkage causes local displacements of cavity walls, with possible occurrence of micro-cracks in the enamel, dentin and/or material itself. In order to design a cavity for experimental testing of polymerization shrinkage of dental composites using 3D optical analysis, in this paper finite element method (FEM) was used to analyze numerical models with different cavity radiuses. 3D optical strain and displacement analysis of composite materials and cavity walls is limited by equipment sensitivity i.e. 0.01% for strain and 1 micron for displacement. This paper presents the development of 3D computer premolar models with varying cavity radiuses, and local stress, strain and displacement analysis using FEM. Model verification was performed by comparing obtained results with data from the scientific literature. Using the FEM analysis of local strains, displacements and stresses exerted on cavity walls, it was concluded that the model with 1 mm radius was optimal for experimental optical 3D displacement analysis.
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Lanovaz, Joel L., Siriporn Khumsap et Hilary M. Clayton. « Quantification of three-dimensional skin displacement artefacts on the equine tibia and third metatarsus ». Equine and Comparative Exercise Physiology 1, no 2 (mai 2004) : 141–50. http://dx.doi.org/10.1079/ecep200415.
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AbstractRoutine study of three-dimensional (3D) tarsal kinematics is hampered by errors due to the displacement of skin surface-tracking markers relative to the underlying bones. Reliable kinematics can be obtained with bone-fixed markers, but an accurate, non-invasive method would have more applications. Simultaneous kinematic data from skin-based and bone-fixed markers attached to the tibia and third metatarsus were collected from three trotting subjects. The motion of the skin-based markers was extracted relative to the underlying bone motion tracked using the bone-fixed markers. The 3D skin displacement patterns for the skin-based markers were parameterized using a truncated Fourier series model. These displacements were expressed in terms of the local coordinate system for each bone. Skin displacement artefacts were observed in all three axes of each bone segment, with the largest displacements occurring at the proximal tibia. The mean skin displacement amplitudes in the tibia were 6.7%, 3.2% and 10.5% of segment length, and for the third metatarsus were 2.6%, 1.4% and 3.8% of segment length, for the craniocaudal, mediolateral and longitudinal segment axes, respectively. Skin displacement patterns could be expressed concisely using the Fourier series model. Displacements were also consistent between subjects, which should allow them to be used as a basis for developing a correction procedure for 3D tarsal joint kinematics.
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Li, Yiran, Dong Zhao, Xueyi Ma, Jianzhong Zhang et Jian Zhao. « Panoramic Digital Image Correlation for 360-Deg Full-Field Displacement Measurement ». Applied Sciences 13, no 3 (3 février 2023) : 2019. http://dx.doi.org/10.3390/app13032019.
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In full-field 3D displacement measurement, stereo digital image correlation (Stereo-DIC) has strong capabilities. However, as a result of difficulties with stereo camera calibration and surface merging, 360-deg panoramic displacement measurements remain a challenge. This paper proposes a panoramic displacement field measurement method in order to accurately measure the shape and panoramic displacement field of complex shaped objects with natural textures. The proposed method is based on the robust subset-based DIC algorithm and the well-known Zhang’s calibration method to reconstruct the 3D shape and estimate the full-field displacements of a complex surface from multi-view stereo camera pairs. The method is used in the determination of the scale factor of the 3D reconstructed surface and the stitching of multiple 3D reconstructed surfaces with the aid of the laser point cloud data of the object under test. Based on a discussion of the challenges faced by panoramic DIC, this paper details the proposed solution and describes the specific algorithms implemented. The paper tests the performance of the proposed method using an experimental system with a 360-deg six camera setup. The system was evaluated by measuring the rigid body motion of a cylindrical log sample with known 3D point cloud data. The results confirm that the proposed method is able to accurately measure the panoramic shape and full-field displacement of objects with complex morphologies.
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Hsu, Cheng Chih, Ju Yi Lee, C. C. Wu et H. C. Shih. « 3D Displacement Measurement with Pico-Meter Resolution Using Single Heterodyne Grating Interferometry ». Key Engineering Materials 381-382 (juin 2008) : 283–86. http://dx.doi.org/10.4028/www.scientific.net/kem.381-382.283.
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The precision positioning device becomes significant requirement in scientific instruments used for the applications of nanotechnology for a few decades. To achieve the high resolution positioning, the sensing methods of displacement sensor become more important in positioning device. In this paper, a novel method is presented for measuring both in-plane/out-plane displacements with the single heterodyne grating interferometry (HGI). We demonstrated the 1D, 2D, and 3D measurement results respectively and the smallest displacement can be detected was better than 6 pm. Furthermore, the nanometer resolution can be ensured within 20 µm displacement. Hence, the in-plane/out-plane measurements with single apparatus can be realized by our method and might be a displacement sensor using in the motorized stage with suitable opto-mechanics structure minimization.
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Daniel, S. E., A. Aref, C. Rabbani, R. Taylor, T. Campbell, F. Shamsa et P. J. Chuba. « Three-dimensional visualization of stranded source migration following prostate brachytherapy. » Journal of Clinical Oncology 29, no 7_suppl (1 mars 2011) : 79. http://dx.doi.org/10.1200/jco.2011.29.7_suppl.79.
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79 Background: The use of radioactive seeds embedded in absorbable vicryl suture material has emerged as one preferred method for prostate cancer brachytherapy. However, it is unclear how strand displacement affects post-implant dosimetry. Our objective was to use CT imaging and 3D reconstruction to determine strand displacement between day zero and day 30 and to assess the dosimetric consequences of strand displacement. Methods: Between March 2006 and December 2009 there were 86 prostate brachytherapy patients with day zero and day 30 post-plan imaging. There was a mean of 18.24 strands per implant, 9.81 loose seeds per implant, and 69.08 total seeds per implant. Substantial strand displacement was identified by inspection. Migrated strands were identified on day zero and day 30 scans and the distance of displacement was measured using 3D fusion software. Results: Of 1550 strands placed, 23 were found to show substantial migration revealed by 3D imaging. These displacements occurred in 21 of the 86 cases. The estimated distance of strand displacement ranged from 0.5 cm to 2.5 cm with an average movement of 1.5 cm. The exact distance of strand displacement ranged from 0.31 m to 3.44 cm, with mean movement of 2.75 cm. Conclusions: 3D imaging reveals unexpected spatial instability in stranded brachytherapy sources. Significant movement may be expected to occur in approximately 1.48% of stranded sources and 24.42% of cases. Factors which predict for the migration of sources remain relatively undefined. Minimal dosimetric effects from strand displacement appear to be offset by resolution of prostate edema. [Table: see text] No significant financial relationships to disclose.
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Wang, Yanqiang, Jun Zhao, Zhongqin Li, Mingjun Zhang, Yuchun Wang, Jialiang Liu, Jianxia Yang et Zhihui Yang. « Retrieving and Verifying Three-Dimensional Surface Motion Displacement of Mountain Glacier from Sentinel-1 Imagery Using Optimized Method ». Water 13, no 13 (29 juin 2021) : 1793. http://dx.doi.org/10.3390/w13131793.
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The time series study of glacier movement is of special importance for rational management of freshwater resources, studying glacier evolution, understanding mechanism of glacier movement, and assessing disasters caused by glacier movement. In this paper, we put forward an optimization scheme for the shortcomings in the calculation method of using remote sensing to invert the three-dimensional (3D) surface motion displacement of glacier. The optimized method consists of Offset Tracking method, Optimizing the offset tracking results by means of iterative filtering, OT-SBAS technology and Conversion of 3D surface motion displacement of glacier. The Urumqi Glacier No. 1 was selected to test the optimized method. The 3D surface motion displacement of Urumqi Glacier No. 1 was retrieved by using the optimized method based on the ascending and descending Sentinel-1 datasets from 19 April to 29 August 2018. The distribution of 3D surface velocity of the Urumqi Glacier No. 1 was obtained in time series, and the accuracy of the inversion results was evaluated by using the field measurement data. The results show that the accuracies of the inverted displacements of east branch of Urumqi Glacier No. 1 (UG1E) were about 0.062, 0.063, and 0.152 m in the east, north and vertical directions, and these values for the west branch (UG1W) were 0.015, 0.020 and 0.026 m, respectively. It is indicated that using Sentinel-1 ascending and descending data and using the optimized method to retrieve the 3D surface motion displacement of glacier should satisfy the requirements of inversing the 3D surface motion displacement of high-latitude mountain glaciers in China.
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Wei, Gang, Jie Hong et Xin Jiang Wei. « 3D Analytical Solution of Soil Deformation Induced by Shield Tunnelling Construction ». Advanced Materials Research 261-263 (mai 2011) : 1814–19. http://dx.doi.org/10.4028/www.scientific.net/amr.261-263.1814.
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Three-dimensional (3D) analytical solution of soil deformation induced by ground loss in shield tunnelling construction was researched. It is put forward that the ground loss ratio is not a fixed value, but changes in driving direction. The calculation formula of ground loss ratio in driving direction was deduced. Based on two-dimensional (2D) analytical solution of uniform ground movement model of shield tunnelling, the three-dimensional analytical solution of ground deformation induced by ground loss is deduced. The settlement in vertical direction and the displacement in lateral horizontal direction at any point can be calculated; and the method is only applied to the construction phase. In analytical calculation: the predicted soil displacements are in good agreement with the measured values, and the method is easy to use; the closer the soil to tunnel is, the faster the lateral horizontal displacement changes; the extent of change of lateral horizontal displacement in longitudinal direction is smaller than displacement in lateral direction.
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FUJIGAKI, Motoharu. « 3D Shape and Displacement Distribution Measurement ». JOURNAL OF THE JAPAN WELDING SOCIETY 84, no 1 (2015) : 90–95. http://dx.doi.org/10.2207/jjws.84.90.
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Yang, Dong Quan, et Hong Peng. « Elasto-Plastic Analysis of Frame Structures under Large Displacement-Rotation Deformations ». Advanced Materials Research 243-249 (mai 2011) : 5968–74. http://dx.doi.org/10.4028/www.scientific.net/amr.243-249.5968.
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A finite element program for elasto-plastic analysis of 3D beams and frame structures under large displacement/rotations is developed. The element is Timoshenko beam element based on mechanics of continuum. Constitutive equations for large displacements/rotations in elastic stage are expressed in an explicit way which is suitable for programming. The modification of constitutive equation is presented for the analysis of elasto-plastic problems. A fiber model is adopted for the calculation of stiffness matrix and internal forces. For solution of nonlinear finite element equations, general displacement control method and semi-modified stiffness matrix method is adopted. The results of numerical experimentation show that the program work well for 3D beams and frame structures under elasto-plastic large displacement/rotations.
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Xu, Lang, Qiang Chen, Jing-Jing Zhao, Xian-Wen Liu, Qian Xu et Ying-Hui Yang. « An Integrated Approach for Mapping Three-Dimensional CoSeismic Displacement Fields from Sentinel-1 TOPS Data Based on DInSAR, POT, MAI and BOI Techniques : Application to the 2021 Mw 7.4 Maduo Earthquake ». Remote Sensing 13, no 23 (29 novembre 2021) : 4847. http://dx.doi.org/10.3390/rs13234847.
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Sentinel-1 Terrain Observation by Progressive Scans (TOPS) data have been widely applied in earthquake studies due to their open-source policy, short revisit cycle and wide coverage. However, significant near-fault displacement gradients and the moderate azimuth resolution of TOPS data make achieving high-precision along-track measurements challenging, which prevents the generation of high-quality three-dimensional (3D) displacement maps. Here, we propose an integrated method to retrieve high-quality 3D displacements based on the differential interferometric SAR (DInSAR), burst-overlap interferometry (BOI), multiple-aperture InSAR (MAI) and pixel offset tracking (POT) techniques, which are achieved to use only two track Sentinel-1 TOPS data with different viewing geometries. The key step of this method is using a weighted fusion algorithm with the interpolated BOI-derived and MAI-derived 3D displacements. In a case study of the 2021 Maduo earthquake, the calculated root mean square errors (RMSEs) from global navigation satellite system (GNSS) data and the InSAR-derived 3D displacement fields were found to be 6.3, 5.8 and 1.7 cm in north–south, east–west and up–down components, respectively. Moreover, the slip model of the 2021 Maduo earthquake jointly estimated by DInSAR and BOI measurements indicates that this seismic event was dominated by sinistral strike-slip motion mixed with some dip-slip movements; the estimated seismic moment was 1.75 × 1020 Nm, corresponding to a Mw 7.44 event.
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Zambanini, C., et D. S. Kieffer. « Hybrid InSARTrac for monitoring interglacial movement patterns ». IOP Conference Series : Earth and Environmental Science 1124, no 1 (1 janvier 2023) : 012028. http://dx.doi.org/10.1088/1755-1315/1124/1/012028.
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Abstract InSARTrac is a hybrid 3D monitoring method, for which controlled field measurements have indicated significant potential for geotechnical applications. Various approaches can be taken to derive 3D displacements from InSAR measurements, such as combining multiple InSAR ascending and descending satellite passes or combining multi-geometrical radar datasets from ground and satellite based radars. InSARTrac is a cost-effective solution requiring only one terrestrial InSAR device and a camera used for feature tracking. This study summarizes the results of glacial displacement measurements that were conducted to test the InSARTrac methodology. The InSARTrac 3D displacement vectors show details concerning glacial retreat dynamics related to a combination of ice flow and volume loss. By extrapolating prior results obtained from controlled field measurements, the resultant displacement vector orientations have an estimated angular error of approximately 5 degrees. With a fixed camera mount and longer monitoring times this error can be further reduced. Current studies are focused on deploying InSARTrac to investigate its potential for landslide and geostructure monitoring.
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Guidi, Gabriele, Umair Shafqat Malik et Laura Loredana Micoli. « Optimal Lateral Displacement in Automatic Close-Range Photogrammetry ». Sensors 20, no 21 (4 novembre 2020) : 6280. http://dx.doi.org/10.3390/s20216280.
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Based on the use of automatic photogrammetry, different researchers made evident that the level of overlap between adjacent photographs directly affects the uncertainty of the 3D dense cloud originated by the Structure from Motion/Image Matching (SfM/IM) process. The purpose of this study was to investigate if, in the case of a convergent shooting typical of close-range photogrammetry, an optimal lateral displacement of the camera for minimizing the 3D data uncertainty could be identified. We examined five different test objects made of rock, differing in terms of stone type and visual appearance. First, an accurate reference data set was generated by acquiring each object with an active range device, based on pattern projection (σz = 18 µm). Then, each object was 3D-captured with photogrammetry, using a set of images taken radially, with the camera pointing to the center of the specimen. The camera–object minimum distance was kept at 200 mm during the shooting, and the angular displacement was as small as π/60. We generated several dense clouds by sampling the original redundant sequence at angular displacements (nπ/60, n = 1, 2, … 8). Each 3D cloud was then compared with the reference, implementing an accurate scaling protocol to minimize systematic errors. The residual standard deviation of error made consistently evident a range of angular displacements among images that appear to be optimal for reducing the measurement uncertainty, independent of each specimen shape, material, and texture. Such a result provides guidance about how best to arrange the cameras’ geometry for 3D digitization of a stone cultural heritage artifact with several convergent shots. The photogrammetric tool used in the experiments was Agisoft Metashape.
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Lee, H. M., Y. H. Kwon, Hyo Seon Park et I. Lee. « Displacement Measurement of an Existing Long Span Steel Box-Girder Using Terrestrial Laser Scanning ». Key Engineering Materials 347 (septembre 2007) : 511–16. http://dx.doi.org/10.4028/www.scientific.net/kem.347.511.
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To make use of a new technology in the field of structural health monitoring, various displacement measuring techniques such as a global positioning system (GPS) and vision-based techniques have been studied and proposed. It was previously introduced a new displacement measuring technique using terrestrial laser scanning (TLS) that remotely samples the surface of an object using laser pulses and generates the three-dimensional (3D) coordinates of numerous points on the surface. In this paper, for an assessment of the capabilities of the measuring technique about existing structures, the field tests for vertical displacement measurement of an existing long span steel box-girder are experimentally carried out. The performance of the technique is evaluated by comparing the displacements obtained from TLS system and displacements directly measured from linear variable displacement transducer (LVDT).
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Jiang, Ping-Lin, Hua Jiang, Yu-Sheng Jiang, Dai Wang, Nan Li et Zhong-He Shi. « IBEM Simulation of Seismic Wave Scattering by a 3D Tunnel Mountain ». Shock and Vibration 2021 (2 février 2021) : 1–23. http://dx.doi.org/10.1155/2021/6643971.
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The seismic wave scattering by a 3D tunnel mountain is investigated by the indirect boundary element method (IBEM). Without loss of generality, the 3D physical model of hemispherical tunnel mountain in an elastic half-space is established, and the influence of the incidence frequency and angle of P or SV wave on the mountain surface displacements is mainly examined. It is shown that there exists quite a difference between the spatial distribution of displacement amplitude under the incident P wave and the one under SV wave and that the incidence frequency and angle of wave, especially the existence of tunnel excavated in the mountain, have a great effect on the surface displacements of mountain; the presence of the tunnel in the mountain may cause the greater amplification of surface displacement, which is unfavorable to the mountain projects. In addition, it should be noted that the tunnel may suffer the more severe damage under the incident SV wave.
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LEOW, YIXUAN, MARABELLE LI-WEN HENG, YIMIN LIU, DANIEL T. P. FONG, CHI CHIU CHAN et PUI WAH KONG. « VALIDITY OF A FBG-BASED SMART SOCK SYSTEM FOR MEASURING TOE GRIP FUNCTION IN HUMAN FOOT ». Journal of Mechanics in Medicine and Biology 20, no 03 (avril 2020) : 2050015. http://dx.doi.org/10.1142/s0219519420500153.
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This study developed a smart sock system using optical fiber technology to measure the toe grip function of individual toes. The system comprised Fiber Bragg grating (FBG) sensors incorporated into a sock garment for measuring maximum toe flexion displacements. Calibration equation of each FBG sensor was determined from 3D motion capture system on 10 female subjects. The validity of the smart sock system was checked by comparing maximum toe flexion displacement against the gold standard of 3D motion capture. The root mean squared error was 0.95 (0.57) cm across 10 toes. The magnitude of toe displacement and error was similar between the left and right feet. In conclusion, the FBG-based smart sock system can successfully measure maximum toe flexion displacements of individual toes simultaneously. This system can be developed to support the evaluation of toe grip function in clinical and field settings.
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Valvez, Sara, Abílio P. Silva et Paulo N. B. Reis. « Compressive Behaviour of 3D-Printed PETG Composites ». Aerospace 9, no 3 (28 février 2022) : 124. http://dx.doi.org/10.3390/aerospace9030124.
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It is known that 3D-printed PETG composites reinforced with carbon or Kevlar fibres are materials that can be suitable for specific applications in the aeronautical and/or automotive sector. However, for this purpose, it is necessary to understand their mechanical behaviour, which is not yet fully understood in terms of compression. Therefore, this study intends to increase the knowledge in this domain, especially in terms of static behaviour, as well as with regard to creep and stress relaxation due to the inherent viscoelasticity of the matrix. In this context, static, stress relaxation and creep tests were carried out, in compressive mode, using neat PETG and PETG composites reinforced with carbon and Kevlar fibres. From the static tests, it was found that the yield compressive strength decreased in both composites compared to the neat polymer. Values around 9.9% and 68.7% lower were found, respectively, when carbon and Kevlar fibres were added to the PETG. Similar behaviour was observed for compressive displacement, where a reduction of 20.4% and 46.3% was found, respectively. On the other hand, the compressive modulus increased by 12.4% when carbon fibres were added to the PETG matrix and decreased by 39.6% for Kevlar fibres. Finally, the stress relaxation behaviour revealed a decrease in compressive stresses over time for neat PETG, while the creep response promoted greater compressive displacement. In both situations, the response was very dependent on the displacement/stress level used at the beginning of the test. However, when the fibres were added to the polymer, higher stress relaxations and compressive displacements were observed.
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Teo, T. A. « 3D DEFORMATION MEASUREMENT OF CONCRETE WALL USING CLOSE-RANGE PHOTOGRAMMETRY ». ISPRS - International Archives of the Photogrammetry, Remote Sensing and Spatial Information Sciences XLIII-B2-2020 (14 août 2020) : 1175–79. http://dx.doi.org/10.5194/isprs-archives-xliii-b2-2020-1175-2020.
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Abstract. Due to the development of digital image processing, digital photogrammetry is becoming an interesting research area in the field of structural monitoring in civil engineering. This study presents a photogrammetric measurement technique for concrete wall deformation monitoring in the destructive experiment. The non-contact photogrammetric measurement technique which provides surface deformation, is more flexible than the contacted single-point measurement technique (e.g., linear variable displacement transducers, LVDT). The major steps of the proposed scheme include (1) camera calibration, (2) orientation modeling, (3) 3D dense matching, and (4) filtering and interpolation for surface deformation. This experiment used two non-metric digital cameras to measure the deformation of a concrete wall in destructive experiment. The validation compared the image-derived and ranger-derived displacements during the experiment with mean error and standard errors of 32 epochs were −0.02mm and 0.81mm, respectively. The correlation between image-derived displacement and LVDT-derived displacement was 0.9803. The advantage of photogrammetry is to derive surface deformation which covered the whole wall during the experiment. In summary, this study demonstrated that photogrammetry is a useful measurement technique for concrete wall destructive experiment.
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Zou, Jin-feng, Song-qing Zuo et Yuan Xu. « Solution of Strain-Softening Surrounding Rock in Deep Tunnel Incorporating 3D Hoek-Brown Failure Criterion and Flow Rule ». Mathematical Problems in Engineering 2016 (2016) : 1–12. http://dx.doi.org/10.1155/2016/7947036.
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In order to investigate the influence of the intermediate principal stress on the stress and displacement of surrounding rock, a novel approach based on 3D Hoek-Brown (H-B) failure criterion was proposed. Taking the strain-softening characteristic of rock mass into account, the potential plastic zone is subdivided into a finite number of concentric annulus and a numerical procedure for calculating the stress and displacement of each annulus was presented. Strains were obtained based on the nonassociated and associated flow rule and 3D plastic potential function. Stresses were achieved by the stress equilibrium equation and generalized Hoek-Brown failure criterion. Using the proposed approach, we can get the solutions of the stress and displacement of the surrounding rock considering the intermediate principal stress. Moreover, the proposed approach was validated with the published results. Compared with the results based on generalized Hoek-Brown failure criterion, it is shown that the plastic radius calculated by 3D Hoek-Brown failure criterion is smaller than those solved by generalized H-B failure criterion, and the influences of dilatancy effect on the results based on the generalized H-B failure criterion are greater than those based on 3D H-B failure criterion. The displacements considering the nonassociated flow rule are smaller than those considering associated flow rules.
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Réthoré, Julien, Fabrice Morestin, Lionel Lafarge et Paul Valverde. « 3D displacement measurements using a single camera ». Optics and Lasers in Engineering 57 (juin 2014) : 20–27. http://dx.doi.org/10.1016/j.optlaseng.2014.01.009.
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Georgsen, Frode, Per Røe, Anne Randi Syversveen et Oddvar Lia. « Fault displacement modelling using 3D vector fields ». Computational Geosciences 16, no 2 (7 janvier 2012) : 247–59. http://dx.doi.org/10.1007/s10596-011-9257-z.
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Liebold, F., H. G. Maas et J. Deutsch. « Photogrammetric determination of 3D crack opening vectors from 3D displacement fields ». ISPRS Journal of Photogrammetry and Remote Sensing 164 (juin 2020) : 1–10. http://dx.doi.org/10.1016/j.isprsjprs.2020.03.019.
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Zhang, Dongsheng, Zhenyang Yu, Yan Xu, Li Ding, Hu Ding, Qifeng Yu et Zhilong Su. « GNSS Aided Long-Range 3D Displacement Sensing for High-Rise Structures with Two Non-Overlapping Cameras ». Remote Sensing 14, no 2 (14 janvier 2022) : 379. http://dx.doi.org/10.3390/rs14020379.
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Image-based displacement measurement techniques are widely used for sensing the deformation of structures, and plays an increasing role in structural health monitoring owing to its benefit of non-contacting. In this study, a non-overlapping dual camera measurement model with the aid of global navigation satellite system (GNSS) is proposed to sense the three-dimensional (3D) displacements of high-rise structures. Each component of the dual camera system can measure a pair of displacement components of a target point in a 3D space, and its pose relative to the target can be obtained by combining a built-in inclinometer and a GNSS system. To eliminate the coupling of lateral and vertical displacements caused by the perspective projection, a homography-based transformation is introduced to correct the inclined image planes. In contrast to the stereo vision-based displacement measurement techniques, the proposed method does not require the overlapping of the field of views and the calibration of the vision geometry. Both simulation and experiment demonstrate the feasibility and correctness of the proposed method, heralding that it has a potential capacity in the field of remote health monitoring for high-rise buildings.
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Xiong, Luyun, Caijun Xu, Yang Liu, Yangmao Wen et Jin Fang. « 3D Displacement Field of Wenchuan Earthquake Based on Iterative Least Squares for Virtual Observation and GPS/InSAR Observations ». Remote Sensing 12, no 6 (18 mars 2020) : 977. http://dx.doi.org/10.3390/rs12060977.
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The acquisition of a 3D displacement field can help to understand the crustal deformation pattern of seismogenic faults and deepen the understanding of the earthquake nucleation. The data for 3D displacement field extraction are usually from GPS/interferometric synthetic aperture radar (InSAR) observations, and the direct solution method is usually adopted. We proposed an iterative least squares for virtual observation (VOILS) based on the maximum a posteriori estimation criterion of Bayesian theorem to correct the errors caused by the GPS displacement interpolation process. Firstly, in the simulation examples, both uniform and non-uniform sampling schemes for GPS observation were used to extract 3D displacement. On the basis of the experimental results of the reverse fault, the normal fault with a strike-slip component, and the strike-slip fault with a reverse component, we found that the VOILS method is better than the direct solution method in both horizontal and vertical directions. When a uniform sampling scheme was adopted, the percentages of improvement for the reverse fault ranged from 3% to 9% and up to 70%, for the normal fault with a strike-slip component ranging from 4% to 8% and up to 68%, and for the strike-slip fault with a reverse component ranging from 1% to 8% and up to 22%. After this, the VOILS method was applied to extract the 3D displacement field of the 2008 Mw 7.9 Wenchuan earthquake. In the East–West (E) direction, the maximum displacement of the hanging wall was 1.69 m and 2.15 m in the footwall. As for the North–South (N) direction, the maximum displacement of the hanging wall was 0.82 m for the southwestern, 0.95 m for the northeastern, while that of the footwall was 0.77 m. In the vertical (U) direction, the maximum uplift was 1.19 m and 0.95 m for the subsidence, which was significantly different from the direct solution method. Finally, the derived vertical displacements were also compared with the ruptures from field investigations, indicating that the VOILS method can reduce the impact of the interpolated errors on parameter estimations to some extent. The simulation experiments and the case study of the 3D displacement field for the 2008 Wenchuan earthquake suggest that the VOILS method proposed in this study is feasible and effective, and the degree of improvement in the vertical direction is particularly significant.
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Sagawa, Ryusuke, Yusuke Higuchi, Ryo Furukawa et Hiroshi Kawasaki. « Acquisition and Visualization of Micro-Vibration of a Sound Wave in 3D Space ». Journal of Robotics and Mechatronics 34, no 5 (20 octobre 2022) : 1024–32. http://dx.doi.org/10.20965/jrm.2022.p1024.
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The acquisition of micro-vibrations is important for analyzing machinery. In the present study, we propose a method for measuring and visualizing the three-dimensional (3D) displacements of such micro-vibrations, especially in the case of sound waves propagating through space. The proposed method uses the speckle patterns of coherent light to measure the minute displacements. Speckle patterns are useful for detecting extremely small displacements owing to their sensitivity to the pose of the object. However, it is impossible to measure the displacement at each position because the pattern changes nonlinearly with respect to large depth changes. Therefore, a method of nonlinear low-dimensional embedding of the speckle pattern is proposed to analyze the displacements and extended to measure micro-displacements in a 3D space. We divided the 3D space into multiple slices and synchronously captured each speckle pattern. The displacements in the entire 3D space were simultaneously recovered by optimizing the embedded vectors, which were consistent in a 3D lattice. The propagation of sound waves in the 3D space was visualized using the volume-rendering technique. The experiments confirmed that the proposed method correctly measured the displacements by comparing them with the ground truth captured by microphones. We also visualized the wavefront of the sound wave propagating through space.
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Zhan, Feng Lin, et Ping Ye. « ANSYS Simulating Analysis of a 3D High-Temperature Stope Reinforced in Advance with Fully Grouted Cable Bolts ». Applied Mechanics and Materials 170-173 (mai 2012) : 525–28. http://dx.doi.org/10.4028/www.scientific.net/amm.170-173.525.
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By using ANSYS, 3D high-temperature stope models based on the in-situ experiment of reinforcement with fully grouted cable bolts in the test stope hangingwall of Dongxiang Copper Mine are established and analyzed. Results show that both displacements of ground surface and stope hangingwall are in their allowable scopes. The surrounding rock rising displacement caused by heated rock expansion can partly or fully offset the subsidence displacement caused by gravity. Hangingwall rising displacement occurs if stope temperature is equal to or greater than 100°C. Mining is safe if stope temperature is equal to or less than 500°C. The stope hangingwall anchoring parameters can meet the requirements of surrounding rock stability in the process of extraction.
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Wu, Ailin, Du Tang, Aidong Wu, Yunqin Liu, Liting Qian et Lei Zhu. « Comparison of the Dosimetric Influence of Applicator Displacement on 2D and 3D Brachytherapy for Cervical Cancer Treatment ». Technology in Cancer Research & ; Treatment 20 (janvier 2021) : 153303382110412. http://dx.doi.org/10.1177/15330338211041201.
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To compare the dosimetric influence of applicator displacement on two-dimensional brachytherapy (2D-BT) and three-dimensional brachytherapy (3D-BT) for cervical cancer. Nineteen patients who received computed tomography-guided tandem-and-ovoid (T&O) brachytherapy were retrospectively selected. Both 2D (point-based) and 3D (volume-based) plans with and without virtual applicator displacement in the 3 axes were created for each patient. Dose changes at point A, D90 of the high-risk clinical target volume (HR-CTV) and intermediate-risk CTV (IR-CTV), and the D0.1cc, D1cc, D2cc, and D5cc of organs-at-risk (OARs) caused by applicator displacement were evaluated. Both 2D-BT and 3D-BT plans were sensitive to T&O applicator displacement. The D90 of the CTV and the dose at point A were very sensitive to applicator displacement in the right–left direction ( X-axis). An applicator shift of >2 mm in the X-axis resulted in a change of >5% in the dose at point A and D90 of HR-CTV and IR-CTV. In addition, the doses to the OARs were mostly affected by applicator displacement in the anterior–posterior direction ( Z-axis). A displacement of <1.5 mm in the Z-axis was required to avoid a dose change of >10% for OARs. For both 2D-BT and 3D-BT plans, T&O displacement greater than ± 2 mm in the X-axis or T&O applicator displacement ± 1.5 mm in the Z-axis resulted in significant dose changes to the tumor and OARs. In comparison with 3D-BT plans, 2D-BT plans delivered a higher dose to the tumor, and the OARs received more undesirable doses when applicator displacement occurred. The influence of applicator displacement on the doses to the tumor and OARs differed between 2D-BT and 3D-BT. Physicians should take individual patient differences into account when selecting a brachytherapy plan to mitigate the influence of applicator displacement.
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Burssens, Arne, Nicola Krähenbühl, Hannes Vermue, Nathan Davidson, Maxwell Weinberg, Chong Zhang, Charles L. Saltzman et Alexej Barg. « Displacement of Sequential Syndesmotic Ankle Injuries Assessed by a 3D Weightbearing CT ». Foot & ; Ankle Orthopaedics 4, no 4 (1 octobre 2019) : 2473011419S0012. http://dx.doi.org/10.1177/2473011419s00123.
Texte intégralRésumé :
Category: Ankle Introduction/Purpose: Syndesmotic ankle injuries are challenging to diagnose, since current 2D imaging techniques try to quantify a 3D displacement. Therefore, our aim was two-fold: to determine displacement of sequential syndesmotic ankle injuries under various amounts of load using a 3D weightbearing CT (WBCT) and to assess the relation with current 2D imaging. Methods: Seven paired male cadaver specimens were included (tibia plateau to toe-tip) and mounted into a custom-built frame. WBCT scans were obtained after different patterns of load (0 kg or 85 kg) were combined with torque (0 Nm or 10 Nm external rotation). These conditions were repeated after each ligament condition: intact ligaments, sequential sectioning of the anterior inferior tibiofibular ligament (AITFL), deltoid ligament (DL), and interosseous membrane (IOM). CT images were segmented to obtain 3D models. These allowed quantification of displacement based on the position of computed anatomical landmarks in reference to the intact position of the fibula. A correlation analysis was performed between the 2D and 3D measurements. Results: The effect of torque caused significant displacements in all directions (P<0.05), except for shortening of the fibula (P>0.05). Weight caused a significant lateral (mean=-1.4 mm, SD=1.5) and posterior translation (mean=-0.6 mm, SD=1.8). The highest displacement consisted of external rotation (mean=-9.4°, SD=6.5) and posterior translation (mean=6.1 mm, SD=2.3) after IOL sectioning combined with torque (Fig. 1). Pearson correlation coefficients were moderate (range 0.31-0.51, P<0.05). Conclusion: Torque demonstrated superiority over weight in detecting syndesmotic ankle instability after 3D analysis. The clinical relevance of these findings can improve diagnosis by incorporating rotatory platforms during imaging and treatment strategies by providing appropriate stabilization against rotation.
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Nadukuru, Srinivasa S., et Radoslaw L. Michalowski. « Three-dimensional displacement analysis of slopes subjected to seismic loads ». Canadian Geotechnical Journal 50, no 6 (juin 2013) : 650–61. http://dx.doi.org/10.1139/cgj-2012-0223.
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Seismic excitation is among the many possible factors contributing to slope failures. Typical design of slopes and analyses of existing slopes are carried out assuming plane strain mechanisms of deformation, and replacing the seismic loading with a uniformly distributed static force. A three-dimensional (3D) analysis of slopes is described in this paper, based on the kinematic theorem of limit analysis. Critical acceleration is calculated for 3D slope failures, and an analysis of a rotating block is executed to develop a solution for displacements of slopes subjected to seismic shaking. The emphasis is more on applying the displacement analysis to a 3D collapse pattern, and less on the choice of ground motion records suitable for the 3D failure analysis of slopes. The analysis is applicable to slopes for which the geometry of the failure pattern is physically confined, as for instance, in the case of excavations. A 3D failure pattern is then expected, and the results of calculations are given for a reasonable range of the width-to-slope-height ratios. The method is illustrated with practical examples.
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Yuan, Bingxiang, Meng Sun, Yixian Wang, Lihua Zhai, Qingzi Luo et Xuqun Zhang. « Full 3D Displacement Measuring System for 3D Displacement Field of Soil around a Laterally Loaded Pile in Transparent Soil ». International Journal of Geomechanics 19, no 5 (mai 2019) : 04019028. http://dx.doi.org/10.1061/(asce)gm.1943-5622.0001409.
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Shi, Jiancun, Zefa Yang, Lixin Wu et Siyu Qiao. « Improving the Robustness of the MTI-Estimated Mining-Induced 3D Time-Series Displacements with a Logistic Model ». Remote Sensing 13, no 18 (21 septembre 2021) : 3782. http://dx.doi.org/10.3390/rs13183782.
Texte intégralRésumé :
The previous multi-track InSAR (MTI) method can be used to retrieve mining-induced three-dimensional (3D) surface displacements with high spatial–temporal resolution by incorporating multi-track interferometric synthetic aperture radar (InSAR) observations with a prior model. However, due to the track-by-track strategy used in the previous MTI method, no redundant observations are provided to estimate 3D displacements, causing poor robustness and further degrading the accuracy of the 3D displacement estimation. This study presents an improved MTI method to significantly improve the robustness of the 3D mining displacements derived by the previous MTI method. In this new method, a fused-track strategy, instead of the previous track-by-track one, is proposed to process the multi-track InSAR measurements by introducing a logistic model. In doing so, redundant observations are generated and further incorporated into the prior model to solve 3D displacements. The improved MTI method was tested on the Datong coal mining area, China, with Sentinel-1 InSAR datasets from three tracks. The results show that the 3D mining displacements estimated by the improved MTI method had the same spatial–temporal resolution as those estimated by the previous MTI method and about 33.5% better accuracy. The more accurate 3D displacements retrieved from the improved MTI method can offer better data for scientifically understanding the mechanism of mining deformation and assessing mining-related geohazards.
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Chang, Hung-Fu, et Mohammad Shokrolah Shirazi. « Integration with 3D Visualization and IoT-Based Sensors for Real-Time Structural Health Monitoring ». Sensors 21, no 21 (21 octobre 2021) : 6988. http://dx.doi.org/10.3390/s21216988.
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Real-time monitoring on displacement and acceleration of a structure provides vital information for people in different applications such as active control and damage warning systems. Recent developments of the Internet of Things (IoT) and client-side web technologies enable a wireless microcontroller board with sensors to process structural-related data in real-time and to interact with servers so that end-users can view the final processed results of the servers through a browser in a computer or a mobile phone. Unlike traditional structural health monitoring (SHM) systems that deliver warnings based on peak acceleration of earthquake, we built a real-time SHM system that converts raw sensor results into movements and rotations on the monitored structure’s three-dimensional (3D) model. This unique approach displays the overall structural dynamic movements directly from measured displacement data, rather than using force analysis, such as finite element analysis, to predict the displacement statically. As an application to our research outcomes, patterns of movements related to its structure type can be collected for further cross-validating the results derived from the traditional stress-strain analysis. In this work, we overcome several challenges that exist in displaying the 3D effects in real-time. From our proposed algorithm that converts the global displacements into element’s local movements, our system can calculate each element’s (e.g., column’s, beam’s, and floor’s) rotation and displacement at its local coordinate while the sensor’s monitoring result only provides displacements at the global coordinate. While we consider minimizing the overall sensor usage costs and displaying the essential 3D movements at the same time, a sensor deployment method is suggested. To achieve the need of processing the enormous amount of sensor data in real-time, we designed a novel structure for saving sensor data, where relationships among multiple sensor devices and sensor’s spatial and unique identifier can be presented. Moreover, we built a sensor device that can send the monitoring data via wireless network to the local server or cloud so that the SHM web can integrate what we develop altogether to show the real-time 3D movements. In this paper, a 3D model is created according to a two-story structure to demonstrate the SHM system functionality and validate our proposed algorithm.
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Wang, Jingjing, Lihua Lyu, Jing Guo, Xiaoqing Xiong, Ying Wang et Fang Ye. « Axial Compression Properties of Special-Shaped 3D Tubular Woven Composites ». AATCC Journal of Research 8, no 2 (1 mars 2021) : 18–25. http://dx.doi.org/10.14504/ajr.8.2.3.
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Axial compression properties of special-shaped 3D tubular woven composites with basalt fiber filament tows were studied. Special-shaped 3D tubular woven fabrics composites with three different thicknesses were woven on an ordinary loom and fabricated by the vacuum assisted resin transfer molding (VARTM) process. Load-displacement and energy-displacement curves were obtained from experimental tests. Results showed that for special-shaped 3D tubular woven composites, the load and energy absorption were greater with thickness and the compression property improved. Through the analysis of the mathematical equation and correlation coefficient of the load-displacement and energy-displacement relation, the fitting effect of the curves were good. The mathematical equation of the method could be used to simplify the functional relationship between load, energy, and displacement.
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Shin, Sung Woo, Cheul Kyu Jung et Kwang Soo Lee. « Control of Lateral Displacement for Super Tall Building by Floor & ; Partial 3D Brace ». Applied Mechanics and Materials 284-287 (janvier 2013) : 1251–58. http://dx.doi.org/10.4028/www.scientific.net/amm.284-287.1251.
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Present control system of lateral displacement for super tall building has problems as follows, stress concentrate on some floor, shear lag, restriction on architectural design, etc. Thus in spite of superior structural ability the efficiency of system is so lessened. This study is about the system that using X type Floor brace and Partial 3D brace, for the purpose of lateral displacement control. This system is a method that distribute lateral loads equally inner wall. According to analysis result, Floor brace and Partial 3D brace system have equal or superior lateral displacement control ability of Outrigger system, by control of brace shape, arrangement, stiffness. When reducing core ratio, Floor brace system shows similar displacement control as outrigger system. If core shape becomes rectangular, Partial 3D brace system does not show difference in maximum displacement in X and Y directions as large as in Outrigger system. Also in case of Outrigger system, abrupt lateral displacement occurs by wind load nearby the outrigger floor. On the contrary, Partial 3D brace system is a structural system advantageous for habitability near specific floor since smaller lateral displacement is shown to reduce the effects of wind vibration and wind acceleration.
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Hale, Dave. « A method for estimating apparent displacement vectors from time-lapse seismic images ». GEOPHYSICS 74, no 5 (septembre 2009) : V99—V107. http://dx.doi.org/10.1190/1.3184015.
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Reliable estimates of vertical, inline, and crossline components of apparent displacements in time-lapse seismic images are difficult to obtain for two reasons. First, features in 3D seismic images tend to be locally planar, and components of displacement within the planes of such features are poorly resolved. Second, searching directly for peaks in 3D crosscorrelations is less robust, more complicated, and computationally more costly than searching for peaks of 1D crosscorrelations. I estimate all three components of displacement with a process designed to mitigate these two problems. I address the first problem by computing for each image sample a local phase correlation instead of a local crosscorrelation. I address the second problem with a cyclic sequence of searches for peaks of correlations computed for lags constrained to one of the three image axes.
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Ali, Tawfek Sheer, Nassr Salman et Mohammed K. Fakhraldin. « Effect of groundwater on the displacements of axially loaded pile in clayey soil ». Pollack Periodica 17, no 1 (25 mars 2022) : 100–104. http://dx.doi.org/10.1556/606.2021.00395.
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Abstract The displacement of a loaded pile could be vertical (axial) or horizontal (lateral); these displacements are sensitive to groundwater presence within the soil mass. This paper presents a theoretical study to investigate vertical and horizontal displacement of piles embedded in a clayey soil for different levels of groundwater under the ground surface. The study was performed using the commercial finite element package PLAXIS-3D. Three diameters of the concrete piles were considered: 0.5, 0.75 and 1 m, and were subjected to 1,000 kN axial load. The effect of 0, 5, 10, 15 and 20 m groundwater along the 20 m pile in length from the ground surface on the vertical and horizontal displacements was investigated. The results indicated that the vertical and horizontal displacements increase when the ground water level increases towards the base of pile. Also, there is a significant increase in the horizontal displacement up to 15 m of groundwater level from ground surface and decreased at levels from 15 to 20 m.
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Gilson, Wesley D., Zequan Yang, Brent A. French et Frederick H. Epstein. « Measurement of myocardial mechanics in mice before and after infarction using multislice displacement-encoded MRI with 3D motion encoding ». American Journal of Physiology-Heart and Circulatory Physiology 288, no 3 (mars 2005) : H1491—H1497. http://dx.doi.org/10.1152/ajpheart.00632.2004.
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Cardiac MRI is an accurate, noninvasive modality for assessing the structure and function of the murine heart. In addition to conventional imaging, MRI tissue tracking methods can quantify numerous aspects of myocardial mechanics, including intramyocardial displacement, strain, twist, and torsion. In the present study, we developed and applied a novel pulse sequence based on displacement-encoded imaging using stimulated echoes (DENSE) that achieves multislice coverage, high spatial resolution, and three-dimensional (3D) displacement encoding. With the use of this technique, myocardial mechanics of C57Bl/6 mice were measured at baseline and 1 day after experimental myocardial infarction. At baseline, the mean systolic transmural circumferential strain was −0.14 ± 0.02 and the mean systolic radial strain was 0.30 ± 0.05. Changes in circumferential and radial strains from the subepicardium to the subendocardium were detected at baseline ( P < 0.05). One day after infarction, significantly reduced 3D displacements and strain were detected in infarcted and noninfarcted myocardium. Infarction also reduced normalized systolic torsion from its baseline value of 1.35 ± 0.27°/mm ( R = 0.99) to 0.07 ± 0.54°/mm ( R = 0.96, P < 0.05). DENSE MRI can assess the 3D myocardial mechanics of the murine heart in <1 h of scan time at 4.7 T and may be applied to studies of myocardial mechanics in genetically engineered mice.
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Ocampos, Montserrat, Miguel Cerro et Fernando Corella. « Arthroscopic Scaphoid 3D Test for Scapholunate Instability ». Journal of Wrist Surgery 07, no 01 (28 avril 2017) : 089–92. http://dx.doi.org/10.1055/s-0037-1601578.
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Background Patients with scapholunate instability usually have pain in the dorsal wrist. This pain may occur due to the impingement between the scaphoid and the dorsal rim of the radius when the scaphoid is detached from the lunate. This pain appears as the scaphoid is displaced over the dorsal rim of the radius. The arthroscopic scaphoid 3D (dorsal, dynamic, displacement) test is described here to check this pathologic dorsal displacement of the scaphoid. Surgical Technique The test should be performed both in the radiocarpal and midcarpal joints. Traction is released and the arthroscope is set under the lunate when tested in the radiocarpal joint and on the lunate when tested in the midcarpal joint. The scaphoid is manually pushed dorsally at the scaphoid tubercle. If there was no scapholunate instability, all the proximal row bones are minimally displaced: a negative test. If there was scapholunate instability, the scaphoid is displaced dorsally while the lunate remains static: evaluated as positive. Clinical Relevance This test can add information to the arthroscopic classifications of the scapholunate instability, which explore both the proximal to distal displacement of the scaphoid (the step-off) and the ulnar to radial displacement (the gap), as this test explores the volar to dorsal displacement.
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Wang, Xiao Gang, Yue Wei Bai et Kai Liu. « Research and Design of Laser Accurate Displacement Measurement System ». Advanced Materials Research 301-303 (juillet 2011) : 1289–92. http://dx.doi.org/10.4028/www.scientific.net/amr.301-303.1289.
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Laser displacement sensor(LDS) displacement measurement is a non-contact measurement with more precision and a wide range of applications.。In this paper, a laser accurate displacement measurement system based on LDS and three-dimensional linear-servomotor-driven actuators (3D LSDA) is presented. The 3D LSDA moving system is composed of linear servo motor, precision movable liner mechanism and servo machine. It is driven to move the noncontact laser displacement sensor to scan surfaces through the three-dimensional electric displacement platform, and then the measurement data is processed. The displacement sensor resolution is 2μm; each dimensional electric displacement platform repeated positioning accuracy is higher than 5μm.
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Jusková, Petra, Lionel Matthys, Jean-Louis Viovy et Laurent Malaquin. « 3D deterministic lateral displacement (3D-DLD) cartridge system for high throughput particle sorting ». Chemical Communications 56, no 38 (2020) : 5190–93. http://dx.doi.org/10.1039/c9cc05858c.
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Liu, Jihong, Jun Hu, Zhiwei Li, Zhangfeng Ma, Jianwen Shi, Wenbin Xu et Qian Sun. « Three-Dimensional Surface Displacements of the 8 January 2022 Mw6.7 Menyuan Earthquake, China from Sentinel-1 and ALOS-2 SAR Observations ». Remote Sensing 14, no 6 (14 mars 2022) : 1404. http://dx.doi.org/10.3390/rs14061404.
Texte intégralRésumé :
The 8 January 2022 Mw6.7 Menyuan earthquake was generated in the transition zone between the western Lenglongling fault and the eastern Tuolaishan fault, both being part of the Qilian–Haiyuan fault system with an important role in the adjustment of the regional tectonic regime. In this study, four pairs of SAR (synthetic aperture radar) data from Sentinel-1 and ALOS-2 (Advanced Land Observation Satellite-2) satellites were used to derive the surface displacement observations along the satellite line-of-sight (LOS) and azimuth directions using the differential interferometric SAR (InSAR, DInSAR), pixel offset-tracking (POT), multiple aperture InSAR (MAI), and burst overlap InSAR (BOI) methods. An SM-VCE method (i.e., a method for measuring three-dimensional (3D) surface displacements with InSAR based on a strain model and variance component estimation) was employed to combine these derived SAR displacement observations to calculate the 3D co-seismic displacements. Results indicate that the 2022 Menyuan earthquake was dominated by left-lateral slip, and the maximum horizontal and vertical displacements were 1.9 m and 0.6 m, respectively. The relative horizontal surface displacement across the fault was as large as 2–3 m, and the fault-parallel displacement magnitude was larger on the southern side of the fault compared with the northern side. Furthermore, three co-seismic strain invariants were also investigated, revealing that the near-fault area suffered severe deformation, and two obviously expanding and compressed zones were identified. We provide displacements/strains derived in this study in the prevailing geotiff format, which will be useful for the broad community studying this earthquake; in addition, the SM-VCE code used in this study is open to the public so that readers can better understand the method.
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Usuki, S., Kazuyuki Enami, M. Hiraki, S. Takahashi et Kiyoshi Takamasu. « Theoretical Analysis and Basic Experiments for the 3D Displacement Measurement Using Ring-Shaped Laser Beam ». Key Engineering Materials 295-296 (octobre 2005) : 295–300. http://dx.doi.org/10.4028/www.scientific.net/kem.295-296.295.
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For flexible 3D positioning of a complex 3D mechanism, it is needed to measure 3D displacement of the end-effecter of the mechanism in high precision and by non-contact method. It was common to use plural sensors or scales together to measure the 3D displacement. However, it is difficult to calibrate the sensitivities of the plural sensors or scales. A novel 3D displacement measurement is proposed using an optical system in which lens focuses are collected at the center of the sphere, which has been used for the radius measurement of the sphere. Instead of facing in the XY direction that has high sensitivity, new ideas are necessary for the measurement in the Z direction of the optics where focuses are collected at the center of the sphere. The displacement in the XY direction and the one in the Z direction can be measured at the same time by using a ring-shaped laser beam instead of a simple ray.
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Rahel, Rahel G. « Measurement of 3D Displacement Fields and Deformation Using 3D Laser Scanner and CCD Camera (0-10 mm) ». Al-Mukhtar Journal of Sciences 28, no 2 (31 décembre 2013) : 31–48. http://dx.doi.org/10.54172/mjsc.v28i2.157.
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Many applications dealing with the mechanical behavior of materials require the measurement of displacement fields or deformation fields. For this type of measurement, optical methods have become unavoidable due to their non-intrusive approach, their high spatial resolution, their high sensitivity, the large size of their examinated field, and the increasing power of the computers that now allow the processing of huge quantities of data. In this context we have developed a system for measuring 3-D displacement fields using CCD (camera charge digital) and 3D laser scanner .This method allows the measure of the 3-D displacement field using at least two pairs of stereoscopic images of an object corresponding to two states of its deformation (or the processing of a sequence of pairs of images acquired during the deformation). The main topics developed in this study are: the calibration of a camera and a 3D laser scanner, and measuring 3D displacement fields from coupling of camera and 3D laser sensor. The potential application of our method is the characterization of structures, for example, to provide assistance in the development of tools for stamping.
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Tung, Shih Heng, Jui Chao Kuo, Ming Hsiang Shih et Wen Pei Sung. « Using the Simplified 3D DIC Method to Measure the Deformation of 3D Surface ». Applied Mechanics and Materials 121-126 (octobre 2011) : 3945–49. http://dx.doi.org/10.4028/www.scientific.net/amm.121-126.3945.
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In recent years, 2D digital image correlation method (DIC) has been widely used in the measurement of plane strain. However, out-of-plane displacement could be induced during the loading and it would affect the measurement accuracy. Thus, a 3D measurement is necessary. This study utilizes a simplified 3D DIC to measure the geometry of an object before and after deformation. Then the finite element concept is involved to determine the strain after deformation. A flat plate specimen with in-plane and out-of-plane displacement is observed. Both 2D and 3D DIC are used to analyze the strain. The results show that using 3D DIC to measure strain is feasible and with a very good accuracy.
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Deng, Xiao Wen, Yu Rong Chen, Bin Bin Dan et Sheng Huai Wang. « The Design of Nanoscale 3D Precision Displacement System ». Applied Mechanics and Materials 456 (octobre 2013) : 199–202. http://dx.doi.org/10.4028/www.scientific.net/amm.456.199.
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A large travel nanoscale 3D precision displacement system is designed with a two-stage coarse-fine driving pattern. Its coarse driving is completed by PID adaptive controller that controls the servo motor and precise ball screw to drive a 1D table, and the fine driving is realized by PZT (piezoelectric microdisplacement actuator). Program control method is adopted to realize the matching of micrometer and nanometer lever driving. A traceable measuring system based on MIP (the Michelson Interference principle) is designed and used to detect positioning, which reduces the accumulated detection error. Experiments verify the effectiveness of the displacement system.
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Teunis, Teun, Niels Bosma, Bart Lubberts, Dirk Ter Meulen et David Ring. « Melone's Concept Revisited : 3D Quantification of Fragment Displacement ». Journal of Hand and Microsurgery 08, no 01 (27 avril 2016) : 027–33. http://dx.doi.org/10.1055/s-0036-1581125.
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Ceccato, Francesca, Alberto Bisson et Simonetta Cola. « Large displacement numerical study of 3D plate anchors ». European Journal of Environmental and Civil Engineering 24, no 4 (30 novembre 2017) : 520–38. http://dx.doi.org/10.1080/19648189.2017.1408498.
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Lee, S. R., Z. S. Luo, H. S. Chiou, B. G. Wang et L. S. Liu. « A Study of the Deformation Measurement of 3D Displacement Field ». Key Engineering Materials 295-296 (octobre 2005) : 313–18. http://dx.doi.org/10.4028/www.scientific.net/kem.295-296.313.
Texte intégralRésumé :
With the development of modern engineering such as micro-electro-mechanical system (MEMS) and new material, the deformation measurement of 3D displacement field is required. Moiré interferometry has become common for measuring the deformations of two-dimension in-plane displacement field. To solve the problem of 3D displacement field, a system for measuring the deformations of 3D displacement field is designed. By using this system, we can measure the out-of-plane displacement by appending a set of electronic speckle interference system based on Moiré interferometry system. Adjusting the incident angle of the incident light, the transmitting direction of the first order diffracted wave in a Moiré interferometry system is assigned to deviate with a small angle from the vertical direction of the specimen surface. Thus the first order diffracted wave is separated from the place of the appended interference field. The striated patterns of the deformations of 3D displacement field can be obtained at the same time. These striated patterns are recorded respectively by three CCD cameras and are stored and processed by a computer. The synchronous measuring method brings certain amount of measuring errors into the measurement of in-plane displacement. This measuring error is analyzed in theory. When real-time measurement is not required, this system can be changed into another system in which the in-plane and the out-of-plane displacement field are measured by time sharing to reduce the measuring errors. The theoretical derivation and a part of experimental results for verification are presented.
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Tehrani, Payam, et Denis Mitchell. « Investigating the Use of Natural and Artificial Records for Prediction of Seismic Response of Regular and Irregular RC Bridges Considering Displacement Directions ». Applied Sciences 11, no 3 (20 janvier 2021) : 906. http://dx.doi.org/10.3390/app11030906.
Texte intégralRésumé :
The seismic responses of continuous multi-span reinforced concrete (RC) bridges were predicted using inelastic time history analyses (ITHA) and incremental dynamic analysis (IDA). Some important issues in ITHA were studied in this research, including: the effects of using artificial and natural records on predictions of the mean seismic demands, effects of displacement directions on predictions of the mean seismic response, the use of 2D analysis with combination rules for prediction of the response obtained using 3D analysis, and prediction of the maximum radial displacement demands compared to the displacements obtained along the principal axes of the bridges. In addition, IDA was conducted and predictions were obtained at different damage states. These issues were investigated for the case of regular and irregular bridges using three different sets of natural and artificial records. The results indicated that the use of natural and artificial records typically resulted in similar predictions for the cases studied. The effect of displacement direction was important in predicting the mean seismic response. It was shown that 2D analyses with the combination rules resulted in good predictions of the radial displacement demands obtained from 3D analyses. The use of artificial records in IDA resulted in good prediction of the median collapse capacity.
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Cho, Chul-Hyun, Beom-Soo Kim, Du-Han Kim et Gu-Hee Jung. « Posterior Displacement and Angulation of Displaced Lateral Clavicle Fractures : A 3-Dimensional Analysis ». Orthopaedic Journal of Sports Medicine 8, no 11 (1 novembre 2020) : 232596712096448. http://dx.doi.org/10.1177/2325967120964485.
Texte intégralRésumé :
Background: The management of lateral clavicle fractures is often challenging because of difficulties in identifying displacement patterns that indicate an unstable fracture. Hypothesis: The aim of this study was to evaluate displacement patterns through analysis using 3-dimensional (3D) rendering software for displaced lateral clavicle fractures. We hypothesized that most displaced lateral clavicle fractures would have posterior displacement and angulation as well as superior displacement of the medial fragment. Study Design: Cross-sectional study; Level of evidence, 3. Methods: Radiographs of 37 displaced lateral clavicle fractures were imported into the 3D rendering software to reconstruct the fracture model. For the computational simulation of fracture reduction, the medial fragment was manipulated and returned into place using the software’s moving tools. Two corresponding points were marked between the medial and lateral fragments to measure 3D spatial location in the x-axis (shortening), y-axis (horizontal displacement), and z-axis (vertical displacement). The displacement angle on the cranial view was also measured based on the medial end of the clavicle. Results: There were 32 cases (86.5%) of superior displacement of the medial fragment (mean, 5.8 mm; range, –6.5 to 19.0 mm), 35 cases (94.6%) of posterior displacement of the medial fracture fragment (mean, 8.8 mm; range, –3.2 to 18.3 mm), and 23 cases (62.2%) of distraction of the fracture site (mean, 2.1 mm; range, –9.2 to 12.2 mm). All 37 patients revealed posterior angulation of the fracture site (mean, 8.9°; range, 2.2°-39.4°). Conclusion: Most displaced lateral clavicle fractures have posterior displacement and angulation as well as superior displacement of the medial fragment. Our results revealed that 3D evaluation of lateral clavicle fracture displacement patterns is useful for assessing fracture stability and making treatment decisions.