scholarly journals Application of 3D Projection Profilometry in the High Speed Impaction Surface Deformation Measurement Research

2020 ◽  
Vol 11 (04) ◽  
pp. 103-115
Author(s):  
Eryi Hu
Keyword(s):  
High Speed ◽  
Surface Deformation ◽  
Deformation Measurement

Free-surface deformation measurement

1997 ◽  
Author(s):  
H. Stahl ◽  
Kevin Stultz ◽  
H. Stahl ◽  
Kevin Stultz
Keyword(s):  
Free Surface ◽  
Surface Deformation ◽  
Deformation Measurement ◽  
Free Surface Deformation

scholarly journals SUBSIDENCE EVALUATION OF HIGH-SPEED RAILWAY IN SHENYANG BASED ON TIME-SERIES INSAR

2018 ◽  
Vol IV-3 ◽  
pp. 273-276
Author(s):  
Yun Zhang ◽  
Lianhuan Wei ◽  
Jiayu Li ◽  
Shanjun Liu ◽  
Yachun Mao ◽  
...  
Keyword(s):  
Time Series ◽  
High Speed ◽  
Cross Validation ◽  
Surface Deformation ◽  
Local Environment ◽  
Local Area ◽  
Safe Operation ◽  
High Speed Rail ◽  
High Speed Railway ◽  
Under Construction

More and more high-speed railway are under construction in China. The slow settlement along high-speed railway tracks and newly-built stations would lead to inhomogeneous deformation of local area, and the accumulation may be a threat to the safe operation of high-speed rail system. In this paper, surface deformation of the newly-built high-speed railway station as well as the railway lines in Shenyang region will be retrieved by time series InSAR analysis using multi-orbit COSMO-SkyMed images. This paper focuses on the non-uniform subsidence caused by the changing of local environment along the railway. The accuracy of the settlement results can be verified by cross validation of the results obtained from two different orbits during the same period.

scholarly journals High-Velocity Shear and Soft Friction at the Nanometer Scale

2021 ◽  
Vol 7 ◽  
Author(s):  
Per-Anders Thorén ◽  
Riccardo Borgani ◽  
Daniel Forchheimer ◽  
David B. Haviland
Keyword(s):  
High Speed ◽  
Surface Deformation ◽  
Soft Materials ◽  
Lateral Force ◽  
Velocity Shear ◽  
Polymer Materials ◽  
Amplitude Dependence ◽  
Dynamic Force ◽  
Stick Slip ◽  
Soft Polymer

We study high-speed friction on soft polymer materials by measuring the amplitude dependence of cyclic lateral forces on the atomic force microscope (AFM) tip as it slides on the surface with fixed contact force. The resulting dynamic force quadrature curves separate the elastic and viscous contributions to the lateral force, revealing a transition from stick-slip to free-sliding motion as the velocity increases. We explain force quadratures and describe how they are measured, and we show results for a variety of soft materials. The results differ substantially from the measurements on hard materials, showing hysteresis in the force quadrature curves that we attribute to the finite relaxation time of viscoelastic surface deformation.

scholarly journals Spatial Baseline Optimization for Spaceborne Multistatic SAR Tomography Systems

Sensors ◽  
2019 ◽  
Vol 19 (9) ◽  
pp. 2106 ◽  
Author(s):  
Jiuchao Zhao ◽  
Anxi Yu ◽  
Yongsheng Zhang ◽  
Xiaoxiang Zhu ◽  
Zhen Dong
Keyword(s):  
Surface Deformation ◽  
Design Method ◽  
Geometric Model ◽  
Three Dimensional ◽  
Optimization Method ◽  
Deformation Measurement ◽  
Experimental Simulation ◽  
Baseline Design ◽  
Imaging Performance ◽  
The Impact

Spaceborne multistatic synthetic aperture radar (SAR) tomography (SMS-TomoSAR) systems take full advantage of the flexible configuration of multistatic SAR in the space, time, phase, and frequency dimensions, and simultaneously achieve high-precision height resolution and low-deformation measurement of three-dimensional ground scenes. SMS-TomoSAR currently poses a series of key issues to solve, such as baseline optimization, spatial transmission error estimation and compensation, and the choice of imaging algorithm, which directly affects the performance of height-dimensional imaging and surface deformation measurement. This paper explores the impact of baseline distribution on height-dimensional imaging performance for the baseline optimization issue, and proposes a feasible baseline optimization method. Firstly, the multi-base multi-pass baselines of an SMS-TomoSAR system are considered equivalent to a group of multi-pass baselines from monostatic SAR. Secondly, we establish the equivalent baselines as a symmetric-geometric model to characterize the non-uniform characteristic of baseline distribution. Through experimental simulation and model analysis, an approximately uniform baseline distribution is shown to have better SMS-TomoSAR imaging performance in the height direction. Further, a baseline design method under uniform-perturbation sampling with Gaussian distribution error is proposed. Finally, the imaging performance of different levels of perturbation is compared, and the maximum baseline perturbation allowed by the system is given.

scholarly journals Deformation heterogeneity and texture in surface severe plastic deformation of copper

2016 ◽  
Vol 472 (2187) ◽  
pp. 20150486 ◽  
Author(s):  
Saurabh Basu ◽  
Zhiyu Wang ◽  
Christopher Saldana
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
High Speed ◽  
Surface Deformation ◽  
Image Correlation ◽  
Surface Mechanical Attrition Treatment ◽  
Model Parameters ◽  
Texture Model ◽  
Mechanical Attrition ◽  
Deformation Mechanics

Comprehensive understanding of thermomechanical response and microstructure evolution during surface severe plastic deformation (S 2 PD) is important towards establishing controllable processing frameworks. In this study, the evolution of crystallographic textures during directional surface mechanical attrition treatment on copper was studied and modelled using the visco-plastic self-consistent framework. In situ high-speed imaging and digital image correlation of surface deformation in circular indentation were employed to elucidate mechanics occurring in a unit process deformation and to calibrate texture model parameters. Material response during directional surface mechanical attrition was simulated using a finite-element model coupled with the calibrated texture model. The crystallographic textures developed during S 2 PD were observed to be similar to those resultant from uniaxial compression. The implications of these results towards facilitating a processing-based framework to predict deformation mechanics and resulting crystallographic texture in S 2 PD configurations are briefly discussed.

Hybrid phase retrieval algorithm based on modified very fast simulated annealing

2018 ◽  
Vol 10 (9) ◽  
pp. 1072-1080 ◽  
Author(s):  
Yueshu Xu ◽  
Qian Ye ◽  
Guoxiang Meng
Keyword(s):  
Simulated Annealing ◽  
High Speed ◽  
Phase Retrieval ◽  
Global Minimum ◽  
High Efficiency ◽  
Surface Deformation ◽  
Digital Simulation ◽  
Retrieval Algorithm ◽  
Very Fast Simulated Annealing ◽  
Short Time

AbstractThe Misell algorithm is one of the most widely used phase retrieval holography methods for large reflector antennas to measure surface deformation. However, it usually locks in a local minimum because it heads downhill from an initial estimation without any consideration whether it heads for a global minimum or not. The core problem of the Misell algorithm is to find an initial estimation near the global minimum to avoid local stagnation. To cope with the problem, we construct a hybrid Misell algorithm, named modified very fast simulated annealing (MVFSA)-Misell algorithm, to search for the global minimum with a high efficiency. The algorithm is based on the combination of the MVFSA algorithm and Misell algorithm. Firstly, the MVFSA is utilized to obtain a rough position near the global minimum in limited steps. Then, the Misell algorithm starts from the rough position to converge to the global minimum with high speed and accuracy. The convergence characteristic of the proposed algorithm was discussed in detail through digital simulation. Simulation results show that the algorithm can reach global minimum in a very short time. Unlike the traditional Misell algorithm, the hybrid algorithm is not influenced by initial phase estimation.

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