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Model for the Whole Roller leveling Process of Plates with Random Curvature Distribution Based on the Curvature Integration Method

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Chinese Journal of Mechanical Engineering 2019年第3期32卷 145-155页

作者： Ben Guan Chao Zhang Yong Zang Yuan Wang School of Mechanical Engineering University of Science and Technology BeijingBeijing 100083China Institute of Artificial Intelligence University of Science and Technology BeijingBeijing 100083China

A model based on the curvature integration method has been applied in an online plate leveling system. However, there are some shortcomings in the current leveling models. On the one hand, the models cannot deal with the leveling process of plates with a random curvature distribution. On the other hand, the current models are suitable only for stable leveling processes and ignore the biting in and tailing out stages. This study presents a new plate-leveling model based on the curvature integration method, which can describe the leveling process of plates with random curvature distribution. Further, the model is solved in two cases in order to take the biting in and tailing out stages into consideration. The proposed model is evaluated by comparing with a plate leveling experiment. Finally, the leveling process of a plate with a wave bent is studied using the proposed model. It is found that the contact angles vary greatly during the biting in and tailing out stages. However, they are relatively steady during the 5 roller leveling stage. In addition, the contact angle of roller No. 2 is the smallest, which is close to 0. Roller leveling can effectively eliminate bending in the plate, but there are regions in the head and tail of the plate, where roller leveling is not effective. The non-leveling region length is about 2 times that of the roller space. This study proposes a quasi-static plate-leveling model, which makes it possible to analyze the dynamic straightening process using a curvature integration method. It also makes it possible to analyze the straightening process of a plate with random curvature distribution.

关键词： leveling Curvature integration method Curvature Contact angle Deflection

Longitudinally profiled plate leveling theory based on linear decreasing leveling scheme

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Journal of Iron and Steel Research(International) 2019年第2期26卷 130-136页

作者： Jian-liang Sun Xing-ming Du Kai Li Yan Peng National Engineering Research Center for Equipment and Technology of Cold Strip Rolling Yanshan UniversityQinhuangdao 066004HebeiChina State Key Laboratory of Metastable Materials Science and Technology Yanshan UniversityQinhuangdao 066004HebeiChina

An an alytical model based on linear decreasi ng leveli ng scheme was proposed to inv estigate the longitu din ally profiled plate leveling process.Considering the variable cross-sectional thickness of longitudinally profiled plate and the dynamic reductions in leveling rolls,the reduction models of upper and lower rolls,the leveling force model and the leveling moment model were established,respectively,based on linear decreasing leveling scheme.Moreover,the finite element model of longitudinally profiled plate leveling process was established based on ABAQUS.Then,the total displacements of upper and lower rolls,the leveling force and the stress distribution of longifudinally profiled plate in the leveling process were calculated.To verify the validity of the proposed models,calculated leveling forces were compared with the measured values,and very good agreements are found.Calculated results show that linear decreasing leveling scheme is suitable for leveling longitudinally profiled plate.

关键词： Longitudi nally profiled plate Lin ear decreasing leveling Dynamic reduction Residual stress

Region Division and Stress Analysis for Plate Roller leveling Process

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Journal of Iron and Steel Research(International) 2005年第6期12卷 27-29页

作者： ZHOU Cun-long WANG Guo-dong LIU Xiang-hua QIN Jian-ping Northeastern University Shenyang 110004 China Taiyuan University of Science and Technology Taiyuan 030024 China

The flatness of leveled plate is settled by residual stress. According to stress distribution simulated by FEM software ANSYS/LS-DYNA, the plate can be divided into non-steady region and steady region. The nonsteady region is composed of four zones, two of which are about half of leveling roller pitch at leading and end edges and other two are about 10% of the width at lateral edges. The steady region is the rest part enclosed by the non-steady regions. It is helpful to improve the leveling process by analyzing forming mechanism of each region and selecting suitable processes settings.

关键词： leveling residual stress non-steady region steady region flatness

Research on Deformation Mode of the Longmenshan-Longriba Region Using GPS and leveling Data

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International Journal of Geosciences 2023年第7期14卷 619-634页

作者： Xudong Li Wei Li Jiangtao Qiu Bing Feng Xiang Liu The Second Monitoring and Application Center China Earthquake Administration Xi’an China Institute of Geology China Earthquake Administration Beijing China

The Longmenshan-Longriba region is located on the eastern edge of the Tibetan Plateau, and is an ideal place to study the eastward extrusion and uplift mechanism of the plateau. Previous studies on this area mainly focused on tectonic activity and seismic hazard, with few studies giving its overall deformation characteristics and dynamic mechanism. This paper uses the latest dense GPS data, combined with precise leveling data to analyze the kinematic characteristics and deformation mode of the Longmenshan fault zone (LMSF) and the Longriba fault zone (LRBF). The results show that both the Longmenshan fault zone and the Longriba fault zone have certain right-lateral strike-slip and thrusting, indicating that they play an important role in adjusting strain distribution and absorbing tectonic deformation;The strain-rate field on the Longriba fault zone is broadly distributed, suggesting that the deformation field is at least partially coupled;while the strain-rate field on the Longmenshan fault zone presents a non-uniform distribution, indicating different dynamic sources acting on segments. The high strain rate areas revealed in this study points us to the high-risk area for future earthquakes. The present-day vertical motion velocity field in the region obtained from leveling and GPS data shows a mismatch between the regional deformation field and active tectonics, which can be explained by the incomplete coupling of deformation between the lower and upper crust.

关键词： Longmenshan Fault Zone Longriba Fault Zone GPS Strain leveling

Mean sea surface heights of the South and East China Seas from ocean circulation model and geodetic leveling

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Chinese Science Bulletin 2002年第4期47卷 326-329页

作者： FANG Guohong WEI Zexun FANG Yue WANG Kai Choi Byungho Institute of Oceanology Chinese Academy of SciencesQingdao 266071China Department of Oceanography Texas A&M UniversityCollege StationTX 77843-3146USA Department of Civil Engineering Sungkyunkwan UniversitySuwon440-746Korea

The mean sea surface heights (sea surface topography) of the South China, East China, Yellow and Bohai Seas are derived from an ocean general circulation model and surface air pressure. The circulation model covers the global oceans, with fine grid (1/6°)? covering the East Asian marginal seas and coarse grid (3°) covering the rest part of the global oceans. The result shows that the China 1985 Na-tional Altitude Datum is 24.7 cm above the mean sea surface height of the world oceans. The mean sea surface in the coastal ocean adjacent to China is higher in the south than in the north. Intercomparison of the model results with the geodetic leveling measurements at 28 coastal tidal stations shows a standard deviation of 4.8 cm and a fitting coefficient of 95.3%. After correction through linear regression, the standard deviation is reduced to 4.5 cm. This indicates that the accuracy of model results is sufficient for practical application. Based on the model results, the mean sea surface heights for the

关键词： mean sea surface height ocean circulation model land leveling South China Sea East China Sea Yellow Sea Bohai Sea.

Using satellite altimetry leveling to assess the marine geoid

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Geodesy and Geodynamics 2020年第2期11卷 106-111页

作者： Zhengtao Wang Nengfang Chao Dingbo Chao School of Geodesy and Geomatics Wuhan UniversityWuhan 430079China College of Marine Science and Technology China University of GeosciencesWuhan 430074China

Based on the concept of Global Position System(GPS)/leveling,the satellite altimetry leveling(SAL) is first proposed to evaluate the marine geoid.SAL is derived by the difference among the mean sea surface(MSS),mean dynamic ocean topography(MDT),and leveling origin.In this study,(1) the original satellite altimetry data are processed to infer the vertical deflection and gravity anomaly,(2) the Chinese coastal marine geoids(CMG) are determined by using the differe nt methods(including Molodensky,least square collocation,Stokes formula,and two-dimensional fast Fourier transformation(FFT) with the vertical deflection and gravity anomaly data),(3) CMG are evaluated by using the results from above different methods,the Gravity field and steady-state Ocean Circulation Explorer(GOCE) gravity potential model(GGPM),and SAL.The results show that(1) CMG from the Molodensky method has the highest precision by using vertical de flection data,(2) the accuracy of CMG indicate good consistency between the SAL and GGPM,(3) SAL can be used as a new method for assessing marine geoid.

关键词： Satellite altimetry leveling Marine geoid Vertical deflection Gravity anomaly

Vertical deformation before and after the 2022 Menyuan Ms6.9 earthquake and analysis of earthquake precursors

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Geodesy and Geodynamics 2023年第6期14卷 582-588页

作者： Sixin Zhang Peng Jia Bowen Hou Ming Hao The Second Monitoring and Application Center China Earthquake AdministrationXi'an 710054China

This study analyzed the vertical deformation before and after the 2022 Menyuan Ms6.9 earthquake in Qinghai Province,China,using leveling profiles across faults measured from Minle County in Gansu Province to Menyuan County in Qinghai Province.Our results suggest the following:(1)The amplitude of regional vertical differential motion near the Sunna-Qilian and Lenglongling faults within the Qilian Shan increased before the 2022 Menyuan earthquake.It was accompanied by the emergence of high gradient deformation zones.Deformation at the Tongziba cross-fault leveling site near the Sunan-Qilian fault was considerable.In contrast,deformation at the Daliang cross-fault leveling site near the stepover region(adjacent to the epicenter)between the Lenglongling and Tuolaishan faults was minor.After 2018,vertical deformation at the Tongziba site notably accelerated,while that at the Daliang site was insignificant.(2)After the 2022 Menyuan earthquake,140—150 mm of subsidence deformation occurred near the Daliang site,while the Tongziba site did not experience significant deformation.(3)Vertical deformation before and after the 2022 Menyuan earthquake conforms with the elastic-rebound theory,and the evolution of pre-earthquake deformation was consistent with the strike-slip fault deformation pattern at different seismogenic stages,i.e.,the relative motion near the locked fault in the late seismogenic stage gradually weakened.The characteristics of strain accumulation and release derived from the vertical deformation before and after the Menyuan MS6.9 earthquake help understand the deformation process of earthquake preparation and earthquake precursors.

关键词： 2022 Menyuan earthquake 2016 Menyuan earthquake leveling Vertical deformation Elastic rebound

Current Vertical Motion Analysis of Northwestern Margin of Ordos Based on Precise leveling

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Earthquake Research in China 2018年第1期32卷 113-118页

作者： Guo Baozhen Ta La Zhou Haitao Su Guangli The First Monitoring and Application Center CEA

Ordos block was squeezed by the Qinghai-Tibetan block and North China block,and the tectonic activity was intense. In the periphery of Ordos block,there was a series of folds zones and compressed faults with complicate structures. This paper used three-phase data of 1980,1990 and 2014 to calculate vertical velocity of Northwestern margin of Ordos and the analytical results indicated that(1) the Hetao basin between the rise of Yinshan fault block and Ordos fault block showed relatively subsidence,in which Linhe basin was the most evident and the subsidence rate was about 2-4 mm/a. The subsidence rate of Jartai-Yinchuan rift zone on the western margin of Ordos block was about 2 mm/a;(2) the whole testing zone exhibited the evident inherited movement characterized by mountain rise and basin subsidence;(3) the two leveling section through the northern margin fault and Dengkou-Benjing fault showed that the difference between vertical velocities on two sides of the fault was less than 0. 5 mm/a.

关键词： Precise leveling Ordos Fault Vertical velocity

Deformation Evolution Characteristics Revealed by GPS and Cross-fault leveling Data before the M_S8. 0 Wenchuan Earthquake

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Earthquake Research in China 2019年第3期33卷 461-477页

作者： ZHAO Jing LIU Jie REN Jinwei YUE Chong LI Jiaojiao State Key Laboratory of Earthquake Dynamics Institute of GeologyCEABeijing 100029China China Earthquake Networks Center Beijing 100045China Institute of Earthquake Forecasting CEABeijing 100036China China Aero Geophysical Survey and Remote Sensing Center for Natural Resources Beijing 100083China

Based on GPS velocity during 1999-2007,GPS baseline time series on large scale during1999-2008 and cross-fault leveling data during 1985-2008,the paper makes some analysis and discussion to study and summarize the movement,tectonic deformation and strain accumulation evolution characteristics of the Longmenshan fault and the surrounding area before the MS8. 0 Wenchuan earthquake,as well as the possible physical mechanism late in the seismic cycle of the Wenchuan earthquake. Multiple results indicate that:GPS velocity profiles show that obvious continuous deformation across the eastern Qinghai-Tibetan Plateau before the earthquake was distributed across a zone at least 500 km wide,while there was little deformation in Sichuan Basin and Longmenshan fault zone,which means that the eastern Qinghai-Tibetan Plateau provides energy accumulation for locked Longmenshan fault zone continuously. GPS strain rates show that the east-west compression deformation was larger in the northwest of the mid-northern segment of the Longmenshan fault zone,and deformation amplitude decreased gradually from far field to near fault zone,and there was little deformation in fault zone. The east-west compression deformation was significant surrounding the southwestern segment of the Longmenshan fault zone,and strain accumulation rate was larger than that of mid-northern segment.Fault locking indicates nearly whole Longmenshan fault was locked before the earthquake except the source of the earthquake which was weakly locked,and a 20 km width patch in southwestern segment between 12 km to 22. 5 km depth was in creeping state. GPS baseline time series in northeast direction on large scale became compressive generally from 2005 in the North-South Seismic Belt,which reflects that relative compression deformation enhances. The cross-fault leveling data show that annual vertical change rate and deformation trend accumulation rate in the Longmenshan fault zone were little,which indicates that vertical activity near the fault was very weak and the fa

关键词： MS8.0 Wenchuan earthquake GPS data Cross-fault leveling data Fault locking Block deformation