Papers by Keyword: Surface Deformation

Abstract: The use of ultrasonic smoothing methods for metal sheet materials opens up new opportunities for improving their performance properties. The paper considers the possibility of increasing the axial stiffness of aluminium thin-walled machine parts by reducing the size of their grains and creating conditions for obtaining nanostructured formations. It has been found that the yield strength of the 8011 grade foil treated with two-way ultrasonic smoothing, depending on the depth of the hardened layer, microstructure and grain size, initially decreases to the middle section, and then increases to its largest value. According to a similar relationship, the relative elongation, i.e. the plasticity of a thin-walled part, changes which also confirms the possibility of formation of nanostructures in the studied layers. Experimental studies have established that the two-way ultrasonic treatment of multilayered plates made of aluminium 8011 grade foil with a thickness of 0.42 mm allows to provide high plasticity and to increase its axial rigidity up to 20.6%, thereby improving the manufacturability of complex machine parts from thin-walled plates by the methods of cold treatment.

Abstract: Measurement of surface deformation is a key component for mapping intraoperative and preoperative image data in image-guided surgery. In this study, we segment CT-scanned images and then use a coherent point drift algorithm for the estimation of surface deformation. To extract surface points, the segmentation is based on the intensity of the image data. The registration of two point sets is considered as a probability density estimation problem in an expectation-maximization framework. Experimental results show that surface deformation between two point sets can be obtained based on the obtained geometric transformation.

Abstract: This paper presents a tool for 3D object mosaic. Given a set of background removed input images, we first compute a 3D reconstructed volumetric model body using shape from silhouette. The granularity of a volumetric body is the user input. Voxel center coordinates, voxel color, and surface normal of the voxel are computed for 3D mosaic. The voxels of reconstructed volumetric body are replaced by primitive shapes such as sphere, cylinder, cone, etc. We call this process as a 3D mosaic. The background-eliminated input images may contain information on body parts supplied by a user. Using information on body parts, only a part of 3D reconstructed volumetric body is replaced by a new shape while the rest of body retains voxel information. The surface normal values are used for primitive shapes with direction such as a cone. 3D mosaic can be used for emphasizing or deemphasizing a part of 3D reconstructed model body, similar to the function of a 2D image mosaic. Emphasizing and deemphasizing is done by resolution, surface normal, size of body parts, color and/or shape of the 3D primitive object.

Abstract: Surface deformation is a slow and irreversible change. It is impacted by topographic, geologic and human activities. To investigate the spatial distribution of surface deformation in Lanzhou, we used PS-InSAR technique. PS-InSAR is a remote sensing method that can be used to detect surface deformation: an indicator of potential hazards. By capturing these deformations over a period of time, we can get valuable information about impending geohazards, such as landslides. This study focused on using this technique to investigate the distribution and cause of surface deformation in the region around Lanzhou, the capital of Gansu Province, China.

Abstract: Analysis of the surface deformation law in mines can provide a significant guide to safety operation of important structures around. For mental mine, field monitoring and simulation are the major methods to study its surface deformation. Chengchao iron mine is a typical mental ore. Taking it as background engineering, the Flac3D is used to simulate its engineering geology condition and mining technology, and study its surface deformation law. It turns out that the simulation results are very close to the field monitoring data. With the mining on, important structures such as ore dressing workshop and new auxiliary shaft will go into the shift line range. It is necessary to adjust the mining program for the safety of the important structures.

Abstract: The atmospheric phase delay due to tropospheric water vapor has been one of the major limitations for the application of high precision repeat pass InSAR. In this paper, we present the atmospheric correction methods and key technology for ASAR interferograms with MODIS integrated water vapor data, then, conduct the atmospheric corrections using ASAR interferometric pair over the Taiyuan region as examples. The experimental results show that the MODIS\ASAR atmospheric correction method can greatly improve the quality of interferogram, and the deformation inversion accuracy can be significantly improved, verify the necessity and reliability of MODIS and ASAR data fusion for obtaining information of surface deformation.

Abstract: The paper discusses the factor and mechanism of the surface deformation caused by shield construction and introduces the process of design and implementation of intelligent prediction system of the surface deformation using BP neural network. It researches the system prediction precision and shows that it is a feasible method to predict the surface deformation.

Abstract: There is a large section tunnel and neighboring tunnels in parallel with cross diaphragm method (CRD) and single excavation by drilling-blasting method at a subway station in Dalian. For the construction of shallow buried tunnels, this article has carried on the numerical simulation analysis of dynamic excavation in order to draw a law of surface deformation due to the interaction effect of CRD and drilling and blasting method by analyzing the surface subsidence in every sequential step. It is concluded that maximum ground settlement point affected by different construction stage and the influence of excavation caused by stress redistribution will keep away from or be close to the large cross section tunnel axis as the reference line whose maximum deviation value is the clear distance of 0.6 times; In different construction stages, the settlement decreases along with the increase of distance far away the maximum ground settlement point; Adjacent tunnel construction has a significant effect on the surface deformation.

Abstract: This paper presented the abrasive wear process of a particle pressing into the material and sliding on the surface simulated by finite element method to reveal wear characteristics and effect factors. The contact stress and surface deformation of material were indicated and material wear resistance was studied, it was found that the stress and the deformation of subsurface not only depends on mechanical properties of material and original surface shape, but also on deformed surface profile due to sliding. In order to prove the effects of material yield stress and deformation harden property on surface deformation and abrasion resistance property, the abrasive wear of three kinds of carbon steel were taken for examples, the simulation results were presented that the larger yield stress of carbon steel, the less surface deformation and the better abrasion resistance property when a particle sliding on the surface. The simulation results also shown that the deformation harden of carbon steel could reduce surface deformation, but couldnt always improve abrasion resistance property.

Abstract: The stability evaluation of highway near a goaf is a key problem in highway construction projects. The goal of this research is to analyze the surface deformation of the highway No.108 in Baoshui area. Both Probability Integral Method (PIM) and Finite Difference Method (FDM) are used and compared to deal with this problem. The main aspects of this research consist of surface subsidence calculation and prediction of surface residual deformation. The results calculated by probability integral method and finite difference method are mainly in agreement,and they are in accord with surface deformation observation results of some sections. So these two kinds of method are proven to be effective in dealing this problem. Moreover, the surface residual deformation was predicted by using numerical simulation based on FLAC^3D. To ensure the highway No.108 security, backfill grouting should be carried out in the areas where collapse pits and ground fissure are found near the highway.