Rainfall-triggered waste dump instability analysis based on surface 3D deformation in physical model test

Landslide is the second largest natural disaster after earthquake. It is of significance to study the evolution laws and failure mechanism of landslides based on its surface 3D deformation information. Based on the rainfall-triggered waste dump instability model test, we studied the failure mechanisms of the waste dump by integrating surface deformation and internal slope stress and proposed novel parameters for identifying landslide stability. We developed a noncontact measurement device, which can obtain millimeter-level 3D deformation data for surface scene in physical model test;Then we developed the similar materials and established a test model for a waste dump. Based on the failure characteristics of slope surface, internal stress of slope body and displacement contours during the whole process, we divided the slope instability process in model test into four stages: rainfall infiltration and surface erosion, shallow sliding, deep sliding, and overall instability. Based on the obtained surface deformation data, we calculated the volume change during slope instability process and compared it with the point displacement on slope surface. The results showed that the volume change can not only reflect the slow-ultra acceleration process of slope failure, but also fully reflect the above four stages and reduce the fluctuations caused by random factors. Finally, this paper proposed two stability identification parameters: the volume change rate above the slip surface and the relative velocity of volume change rate. According to the calculation of these two parameters in model test, they can be used for study the deformation and failure mechanism of slope stability.

The Deformation Analysis of the 3D Alignment Control Network Based on the Multiple Congruence Models

In the construction and maintenance of particle accelerators,all the accelerator elements should be installed in the same coordinate system,only in this way could the devices in the actual world be consistent with the design drawings.However,with the occurrence of the movements of the reinforced concrete cover plates at short notice or building deformations in the long term,the control points upon the engineering structure will be displaced,and the fitness between the subnetwork and the global control network may be irresponsible.Therefore,it is necessary to evaluate the deformations of the 3D alignment control network.Different from the extant investigations,in this paper,to characterize the deformations of the control network,all of the congruent models between the points measured in different epochs have been identified,and the congruence model with the most control points is considered as the primary or fundamental model,the remaining models are recognized as the additional ones.Furthermore,the discrepancies between the primary S-transformation parameters and the additional S-transformation parameters can reflect the relative movements of the additional congruence models.Both the iterative GCT method and the iterative combinatorial theory are proposed to detect multiple congruence models in the control network.Considering the actual work of the alignment,it is essential to identify the competitive models in the monitoring network,which can provide us a hint that,even the fitness between the subnetwork and the global control network is good,there are still deformations which may be ignored.The numerical experiments show that the suggested approaches can describe the deformation of the 3D alignment control network roundly.

Study on Asymmetric Deformation Law and Surrounding Rock Control Technology of High Stress Soft Rock Crossing Roadway

In order to solve the problem of asymmetric large deformation of high-stress soft rock crossing roadway under complex geological conditions in deep mines, taking the 2# total return airway of 76.2# section of Wuyang Coal Mine as the engineering background, the causes of asymmetric deformation and failure of soft rock crossing roadway in deep mines were summarized and analyzed by means of field investigation, theoretical analysis and numerical simulation, and the asymmetric high-efficiency support technology with large row spacing was studied. The results show that the lithology of roadway strata is the main cause of asymmetric deformation and failure of roadway. The shape change of roadway is not the main influencing factor of asymmetric deformation of roadway, but for the control of roadway surrounding rock, the straight wall semi-circular arch roadway is better than the rectangular roadway. The field industrial test shows that after adopting the new support design scheme, the displacement of the roof and floor of the roadway is reduced by 86.39% compared with the original support design scheme, and the displacement of the two sides of the roadway is reduced by 86.05% compared with the original support design scheme, which can ensure the normal and safe production of the roadway during the service period, and provide reference for the support design of other similar geological conditions.

Present-day 3D deformation field of Northeast China,observed by GPS and leveling

A broad view of present-day 3D deformation field around the Northeast China region was derived from GPS and leveling observations. We draw the following conclusions： First, the Northeast China region moved towards northwest with an average velocity of 5 ram/a, with respect to South China. The entire Northeast China region was in a low strain state from the strain rate field. Second, we processed two periods of first- order leveling data in 1970s and 1990s, showing the vertical deformation of the Northeast China region is ＂uplift in western part and subsidence in eastern part＇

Elastoplastic 3D Deformation and Stress Analysis of Strip Rolling

An elastoplastic method for analyzing the 3D deformation, stress and transverse distribution of tension stress during cold strip rolling is developed. The analysis is based on the elastoplastic variational principle in which a kinematically admissible velocity field is constructed with the lateral flow function as an unknown function. The stress distribution and volume strain distribution are obtained by solving the simultaneous equations formed by the longitudinal differential equation of equilibrium and constitutive equations. The lateral flow function is determined by minimizing the total energy dissipation rate. Experimental investigation was carried out on a reversible cold mill. The front tension stress distributions in cold rolled strips were measured by a multi roll segmented tension sensing shapemeter. The calculated results are in good agreement with the measured ones.

Stereo particle image velocimetry measurement of 3D soil deformation around laterally loaded pile in sand

A developed stereo particle image velocimetry(stereo-PIV) system was proposed to measure three-dimensional(3D) soil deformation around a laterally loaded pile in sand.The stereo-PIV technique extended 2D measurement to 3D based on a binocular vision model,where two cameras with a well geometrical setting were utilized to image the same object simultaneously.This system utilized two open software packages and some simple programs in MATLAB,which can easily be adjusted to meet user needs at a low cost.The failure planes form an angle with the horizontal line,which are measured at 27°-29°,approximately three-fourths of the frictional angle of soil.The edge of the strain wedge formed in front of the pile is an arc,which is slightly different from the straight line reported in the literature.The active and passive influence zones are about twice and six times of the diameter of the pile,respectively.The test demonstrates the good performance and feasibility of this stereo-PIV system for more advanced geotechnical testing.

Effective grouting area of jointed slope and stress deformation responses by numerical analysis with FLAC^(3D)

To study the grouting reinforcement mechanism in jointed rock slope, first, the theoretical deduction was done to calculate the critical length of slipping if the slope angle is larger than that of joint inclination; Second, the numerical calculation model was founded by FLAG^3D, so as to find the stress and deformation responses of rock mass in the state before and after grouting, the analysis results show that the range between the boundary of critical slipping block and the joint plane that passes the slope toe is the effective grouting area （EGA）. After excavation, large deformation occurs along the joint plane. After grouting, the displacements of rock particles become uniform and continuous, and large deformations along the joint plane are controlled; the dynamic displacement can re- flect the deformation response of slope during excavation in the state before and after grouting, as well as the shear location of potential slip plane. After grouting, the dynamic displacement of each monitoring point reaches the peak value with very few time steps, which indicate that the parameters of the joint plane, such as strength and stiffness, are improved; the stress field becomes uniform. Tensile area reduces gradually; whole stability of the slope and its ability to resist tensile and shear stress are improved greatly.

3D deformation effect and optimal excavated design of surface mine

The three-dimensional （3D） deformation effect of the slope engineering under the step-by-step excavation for the Antaibao surface mine was analyzed using the FLAC^3D technique. An optimal excavated scheme with a relatively steeper slope angle of 47° instead of 30° was successfully implemented at the west wall in the geological section 73200 of the mine area, where the 3D effect of the nonlinear large deformation of the slope was taken into account. Based on the above research conclusion, put forward the countermeasures of shortening mining length, excavating by different regions, timely foot backfilling to protect the excavated slope, and monitoring and feedback adjustment by studying the nonlinear effect. The results show that these countermeasures are effective in controlling maximum deformation and increasing the stability of the slope.

A Method of Obtaining Deformation Information by Tracing Deformation from Sections for 3D FE Simulation

With the development of computer technology and finite element method, the priority research area of plasticforming has focused on 3D FE simulation of forming processes for components with complicated geometrical shape.These processes have complex deforming mechanism, and different sections have different deforming characteristics.Therefore, for making a simple, convenient, and practical analysis of its deforming law, how to obtain deformationinformation of key sections from the results of 3D FE simulation has become one of problems urgently to be solved.So, a method of obtaining deformation information by tracing deformation from sections for 3D FE simulation hasbeen proposed. From the deformation information got by this method, the deformation law of key locations and thewhole deforming body can be obtained. This method can also help to compare the result from FE simulation withthat from physical modeling. Key procedures of this method have been presented in detail, and it has been testedby applying to 3D FE simulation of precision forging of the blade with a damper platform. The result shows thatthe method is practicable and reliable, and it can also be applied to 3D FE simulation of plastic forming processes ofother components.

SIMULATION OF 3-D DEFORMATION AND MATERIAL FLOW DURING ROLL FORGING PROCESS USING SYSTEM OF OVAL-ROUND GROOVE

Basing on the analysis of the traits of the roll forging process, a system-model of computer simulation has been established. Three-dimensional rigid-plastic FEM has been used for the simulation of the deformation process in the oval and round pass rolling, including the entering, rolling, and separating stages. The analysis was conducted using the Deform-3D ver.5.0 code. The important information concerned with the deformation area characteristic, material flow, and velocity field has been presented. Otherwise, the location of the neutral plane in the deformation area was shown clearly.

A Laplacian Surface Deformation and Optimization Based 3D Registration Algorithm for Image Guided Prostate Radiotherapy

Purpose: To develop a fast landmark-based deformable registration method to capture the soft tissue transformation between the planning 3D CT images and treatment 3D cone-beam CT (CBCT) images for the adaptive external beam radiotherapy (EBRT). Method and Materials: The developed method was based on a global-to-local landmark-based deformable registration algorithm. The landmarks were first acquired by applying a fast segmentation method using the active shape model. The global registration method was applied to establish a registration framework. The Laplacian surface deformation (LSD) and Laplacian surface optimization (LSO) method were then employed for local deformation and remeshing respectively to reach an optimal registration solution. In LSD, the deformed mesh is generated by minimizing the quadratic energy to keep the shape and to move control points to the target position. In LSO, a mesh is reconstructed by minimizing the quadratic energy to smooth the object by minimizing the difference while keeping the landmarks unchanged. The method was applied on 8 EBRT prostate datasets. The distance and volume based estimators were used to evaluate the results. The target volumes delineated by physicians were used as gold standards in the evaluation. Results: The entire segmentation and registration processing time was within 1 minute for all the datasets. The mean distance estimators ranged from 0.43 mm to 2.23 mm for the corresponding model points between the treatment CBCT images and the registered planning images. The mean overlap ratio ranged from 85.5% to 93.2% of the prostate volumes after registration. These results demonstrated reasonably good agreement between the developed method and the gold standards. Conclusion: A novel and fast landmark-based deformable registration method is developed to capture the soft tissue transformation between the planning and treatment images for prostate target volumes. The results show that with the method the image registration and transformation can be completed within one minute and has the potential to be applied to real-time adaptive radiotherapy.

Measuring 3D face deformations from RGB images of expression rehabilitation exercises

Background The accurate(quantitative)analysis of 3D face deformation is a problem of increasing interest in many applications.In particular,defining a 3D model of the face deformation into a 2D target image to capture local and asymmetric deformations remains a challenge in existing literature.A measure of such local deformations may be a relevant index for monitoring the rehabilitation exercises of patients suffering from Par-kinson’s or Alzheimer’s disease or those recovering from a stroke.Methods In this paper,a complete framework that allows the construction of a 3D morphable shape model(3DMM)of the face is presented for fitting to a target RGB image.The model has the specific characteristic of being based on localized components of deformation.The fitting transformation is performed from 3D to 2D and guided by the correspondence between landmarks detected in the target image and those manually annotated on the average 3DMM.The fitting also has the distinction of being performed in two steps to disentangle face deformations related to the identity of the target subject from those induced by facial actions.Results The method was experimentally validated using the MICC-3D dataset,which includes 11 subjects.Each subject was imaged in one neutral pose and while performing 18 facial actions that deform the face in localized and asymmetric ways.For each acquisition,3DMM was fit to an RGB frame whereby,from the apex facial action and the neutral frame,the extent of the deformation was computed.The results indicate that the proposed approach can accurately capture face deformation,even localized and asymmetric deformations.Conclusion The proposed framework demonstrated that it is possible to measure deformations of a reconstructed 3D face model to monitor facial actions performed in response to a set of targets.Interestingly,these results were obtained using only RGB targets,without the need for 3D scans captured with costly devices.This paves the way for the use of the proposed tool in remote medical rehabilitation monitoring.

基于DEFORM-3D的支撑销冷挤压成形数值模拟

采用冷挤压工艺成形支撑销,相对于传统切削加工方法,可降低能耗、提高工效。基于刚塑性有限元法,采用DEFORM-3D对支撑销冷挤压成形过程进行了数值模拟,揭示其变形过程中的金属流动规律,分析了速度场、应力应变场和凸模行程载荷曲线的特点,研究了挤压速度对支撑销挤压成形过程的影响规律。结果表明,支撑销的冷挤压成形过程可分为3个阶段:镦粗变形阶段、型腔填充阶段和最终成形阶段;支撑销两凸缘处变形较剧烈,应力最大;凸模运动速度越快,凸模受到的载荷越大。模拟结果表明,冷挤压成形支撑销工艺方案是可行的。

基于Deform 3D的高速超高速磨削温度的仿真研究

采用有限元分析软件Deform 3D建立了适合高速磨削仿真的Johnson-Cook材料本构模型,构建了反映金属磨削过程高温、大应变及高应变率状态的切削模型,模拟了40Cr钢磨削加工过程,对磨削弧区温度场、热流以及温度变化的仿真结果进行了分析,验证了有限元模型的合理性,为实现对工艺参数的优化选择奠定了理论基础。

基于Deform-3D的车削残余应力分析

切削加工残余应力是零件疲劳强度的重要影响因素,因此对残余应力的研究具有很大的实际指导作用。文章根据热—弹塑性有限元理论,在DEFORM-3D中建立铝合金7075的三维有限元模型,对车削加工表面残余应力进行分析,得到不同切削用量和前角对表面残余应力的影响规律。结果表明:在切削用量和前角一定变化范围内,工件表面在切削方向主要产生残余压应力;在进给方向主要产生残余拉应力,随着距表面层深度的增加,残余拉应力逐渐变为残余压应力。

Deform 3D软件支持的球头铣刀铣削仿真分析

球头铣刀铣削过程包含复杂的多物理场耦合作用,且球头铣刀刀刃特殊,分析较为困难。在商业有限元软件Deform 3D前处理器中建立了球头铣刀铣削有限元模型,运用可靠的材料模型及切屑分离、断裂准则,采用合理的摩擦模型和传热模型,施加恰当的边界条件,进行了连续两刀齿的仿真模拟铣削过程,得到了铣削力、工件温度场和残余应力场的仿真结果,并分析了铣削速度、进给量、铣削深度等工艺参数对结果的影响。

基于Deform 3D的高速车削加工仿真研究

基于有限元分析软件Deform 3D对高速车削加工进行仿真研究,通过实例分析了车削过程中切屑的形成过程,切削力大小、切削温度及应力应变的分布情况。该仿真结果对车削工艺效果的预测和优化具有现实的指导意义。

基于DEFORM 3D的ADI切削力有限元仿真

为更好的研究金属材料的切削加工过程,以DEFORM 3D软件为平台,利用有限元法对等温淬火球墨铸铁的切削进行了建模与仿真,分析得到了切削速度、切削深度、进给量对切削力的影响规律。通过有限元法计算刀具的切削力,得出了切削力分别在不同切削深度和不同进给量下的变化规律,并以试验数据为基础,将仿真数据和传统经验公式的计算数据进行对比与分析。研究结果表明,影响切削力的主要因素是切削深度,其次是进给量,影响最小的是切削速度。

基于Deform 3D内齿冷挤压数值模拟分析

利用Deform 3D有限元软件对内齿的冷挤压进行数值模拟,通过网格划分、有限元方法(FEM)求解器和点追踪等功能的应用,对速度、应力和应变进行分析,从而得到金属成形过程的流动规律、力学场分布情况以及存在的问题.

基于Deform-3D的准干式深孔钻削有限元分析

采用Deform-3D有限元分析软件对准干式BTA单刃内排屑深孔钻钻削做了仿真研究。应用Deform-3D软件设置模拟参数为干式钻削,在不同的切削用量情况下对切削力的大小、刀具磨损以及切削温度场进行了仿真分析,讨论了断屑的发生位置以及分屑的形成过程,为准干式深孔加工的切削参数和刀具参数进一步的优化提供了依据。