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| 1 | Forming limits under multi-index constraints in NC bending of aluminum alloy thin-walled tubes with large diameters显示文摘With increasing diameters of aluminum alloy thin-walled tubes (AATTs), the tube forming limits, i.e. the minimum bending factors, and their predictions under multi-index constraints including wrinkling, thinning and flattening have been being a key problem to be urgently solved for improving tube forming potential in numerical control (NC) bending processes of AATTs with large diameters. Thus in this paper, a search algorithm of the forming limits is put forward based on a 3D elastic-plastic finite element (FE) model and a wrinkling energy prediction model for the bending processes under axial compression loading (ACL) or not. This algorithm enables to be considered the effects of process parameter combinations including die, friction parameters on the multi-indices. Based on this algorithm, the forming limits of the different size tubes are obtained, and the roles of the process parameter combinations in enabling the limit bending processes are also revealed. The followings are found: the first, within the appropriate ranges of friction and clearances between the different dies and the tubes enabling the bending processes with smaller bending factors, the ACL enables the tube limit bending processes after a decrease of the mandrel ball thickness and diameters; then, without considering the effects of the tube geometry sizes on the tube constitutive equations, the forming limits will be decided by the limit thinning values for the tubes with diameters smaller than 80 mm, while the wrinkling for the tubes with diameters no less than 80 mm. The forming limits obtained from this algorithm are smaller than the analytical results, and reduced by 57.39%; the last, the roles of the process parameter combinations in enabling the limit bending processes are verified by experimental results. | YAN Jing, YANG He, ZHAN Mei & LI Heng College of Materials Science and Engineering, State Key Laboratory of Solidification Processing, Northwestern Polytechnical University, Xi’an 710072, China | 2010 | Science China(Technological Sciences)2010，53，2： | 21 |
| 2 | Theoretical analysis on bending behavior of functionally graded composite beam crack-controlled by ultrahigh toughness cementitious composites显示文摘Ultrahigh toughness cementitious composites (UHTCC) obviously show strain hardening property under tensile or bending loading. The failure pattern of the UHTCC components exhibits multiple fine cracks under uniaxial tensile loading with prominent tensile strain capacity in excess of 3%, with merely 60 μm average crack width even corresponding to the ultimate tensile strain state. The approach adopted is based on the concept of functionally-graded concrete, where part of the concrete, which surrounds the main longitudinal reinforcement in a RC (reinforced concrete) member, is strategically replaced with UHTCC with excellent crack-controlling ability. Investigations on bending behavior of functionally-graded composite beam crack controlled by UHTCC has been carried out, including theo- retical analysis, experimental research on long composite beams without web reinforcement, validation and comparison between experimental and theoretical results, and analysis on crack control. In addition to improving bearing capacity, the results indicate that functionally-graded composite beams using UHTCC has been found to be very effective in preventing corrosion-induced damage compared with RC beams. Therefore, durability and service life of the structure could be enhanced. This paper discusses the development of internal force and crack propagation during loading process, and presents analysis of the internal force in different stages, moment-curvature relationship from loading to damage and calculation of mid-span deflection and ductility index. In the end, the theoretical formulae have been validated by experimental results. | XU ShiLang LI QingHua | 2009 | Science China(Technological Sciences)2009，52，2： | 17 |
| 3 | NEW SOLUTION SYSTEM FOR CIRCULAR SECTOR PLATE BENDING AND ITS APPLICATION显示文摘Instead of the biharmonic type equation,a set of new governing equations and solvingmethod for circular sector plate bending is presented based on the analogy between plate bending andplane elasticity problems.So the Hamiltonian system can also be applied to plate bending problems byintroducing bending moment functions.The new method presents the analytical solution for the circu-lar,sector plate.The results show that the new method is effective. | Yao, W Zhong, WX Su, B | 1999 | Acta Mechanica Solida Sinica1999，12，4： | 15 |
| 4 | Experimental study and stress analysis of rock bolt anchorage performance显示文摘A new method was developed to apply pull-and-shear loads to the bolt specimen in order to evaluate the anchorage performance of the rebar bolt and the D-Bolt.In the tests,five displacing angles(0,20,40,60,and 90),two joint gaps(0 mm and 30 mm),and three kinds of host rock materials(weak concrete,strong concrete,and concrete-granite) were considered,and stressestrain measurements were conducted.Results show that the ultimate loads of both the D-Bolt and the rebar bolt remained constant with any displacing angles.The ultimate displacement of the D-Bolt changed from 140 mm at the0 displacing angle(pure pull) to approximately 70 mm at a displacing angle greater than 40.The displacement capacity of the D-Bolt is approximately 3.5 times that of the rebar bolt under pure pull and50% higher than that of the rebar bolt under pure shear.The compressive stress exists at 50 mm from the bolt head,and the maximum bending moment value rises with the increasing displacing angle.The rebar bolt mobilises greater applied load than the D-Bolt when subjected to the maximum bending.The yielding length(at 0) of the D-Bolt is longer than that of the rebar bolt.The displacement capacity of the bolts increased with the joint gap.The bolt subjected to joint gap effect yields more quickly with greater bending moment and smaller applied load.The displacement capacities of the D-Bolt and the rebar bolt are greater in the weak host rock than that in the hard host rock.In pure shear condition,the ultimate load of the bolts slightly decreases in the hard rock.The yielding speed in the hard rock is higher than that in the weak rock. | Yu Chen | 2014 | Journal of Rock Mechanics and Geotechnical Engineering2014，6，5： | 13 |
| 5 | ON THE ACCURACY OF THE QUASICONFORMING AND GENERALIZED CONFORMING FINITE ELEMENTS显示文摘It is observed in practice that the numerical accuracy of the two unconventional plate elements, i. e., the nine parameter quasi-conforming and generalized conforming elements, is better than that of the usual Zienkiewicz in compatible cubic element and of a new element proposed recently by Specht, although all these elements have the same asymptotical rate of convergence O(h) in the energy norm. In the paper a careful error analysis for the quasi-conforming and generalized conforming elements is given. It is shown that the consistency error due to nonconformity of the two unconventional elements is of order O(h^2), one order high than that of other conventional nonconforming elements with nine parameters. | 石钟慈 | 1990 | Chinese Annals of Mathematics,Series B1990，11，2： | 10 |
| 6 | Bending behaviors of large diameter thin-walled CP-Ti tube in rotary draw bending | Zhi-yong ZHANG He YANG Heng LI Ning REN Yu-li TIAN | 2011 | Progress in Natural Science:Materials International2011，21，5： | 8 |
| 7 | Performance of a novel bent-up bars system not interacting with concrete显示文摘Increasing the bending and shear capacities of reinforced concrete members is an interesting issue in structural engineering.In recent years,many studies have been carried out to improve capacities of reinforced concrete members such as using post and pre-tensioning,Fiber Reinforced Polymer and other techniques.This paper proposes a novel and significant technique to increase the flexural capacity of simply supported reinforced concrete beams.The proposed method uses a new reinforcement bar system having bent-up bars,covered with rubber tubes.This technique will avoid interaction of bent-up bars with concrete.They are located in the zone where compressive and tensile forces act against one anothe匚The compressive force in the upper point of the bent-up bars is exerted to the end point of these bars located under neutral axis.Moreover,the tensile stress is decreased in reinforcements located under the neutral axis.This will cause the Reinforced Concrete(RC)beam to endure extra loading before reaching yield stress.These factors may well be considered as reasons to increase bending capacity in the new system.The laboratory work together with finite element method analysis were carried out in this investigation.Furthermore,bending capacity,ductility,strength,and cracking zone were assessed for the new proposed system and compared with the conventional model.Both the FEM simulation and the experimental test results revealed that the proposed system has significant impact in increasing the load bearing capacity and the stiffness of the RC beams.In the present study,an equation is formulated to calculate bending capacity of a new reinforcement bar system beam. | Aydin SHISHEGARAN Mohammad Reza GHASEMI Hesam VARAEE | 2019 | Frontiers of Structural and Civil Engineering2019，13，6： | 8 |
| 8 | ANALYSIS OF PIPELINE BEHAVIOURS DURING LAYING OPERATION显示文摘On the S-lay pipeline analysis, the stiffened catenary method which usually can only be used to determine the configuration of sag-bend of pipeline is now expanded to solve that on the total length of pipeline in the first part of this paper. In the second part, a finite difference procedure of S-lay analysis is presented, which is successfully used to solve 2-D problem with a consideration of current load and the effects of inclination as well as elasticity of sea bed as shown in dimensionless curves and some examples. | Gu, Yongning | 1989 | China Ocean Engineering1989，4，4： | 8 |
| 9 | ANOMALOUS BEHAVIOR REVISITED:DYNAMIC RESPONSE OF ELASTIC-PLASTIC STRUCTURES显示文摘Based on the minimum principle of acceleration in the elastic-plastic continua under fi-nite deformation,the dynamic response of an elastic-perfectly plastic pin-ended beam subjected to rect-angular impulse loading is studied with the help of a numerical approach.The calculated results once a-gain show the anomalous behavior of the beam during its response process,which was previously foundin[1].By carefully analyzing the instantaneous distribution of the bending moment,the membraneforce,the curvature and displacement during the response process,it is concluded that the interactiveeffect between the geometry and materials nonlinearities of the structure is the key reason for leading tothe anomalous behavior.This will be helpful for clarifying some misunderstandings in explaining theproblem before. | Xi, F Yang, JL Li, ZL | 1998 | Acta Mechanica Solida Sinica1998，11，4： | 7 |
| 10 | SYNTHESIS AND CHARACTERIZATION OF NOVEL MULTIFUNCTIONAL HOST COMPOUNDS.1.β-CYCLODEXTRIN DERIVATIVE BEARING DIETHANOLAMINE MOIETY显示文摘A novel β-cyclodextrin(β-CD)derivative bearing diethanolamine moietywas synthesized by a convenient method with 63% yield,and the new host compound wascharacterized by (13)~C-NMR,FT-IR spectra etc, | Bao Jian SHEN Lin Hui TONG Dao Sen JIN Lanzhou Institute of Chemical Physics,Chinese Academy of Sciences,Lanzhou,730000 | 1991 | Chinese Chemical Letters1991，2，3： | 7 |
| 11 | Bending and vibration analyses of a rotating sandwich cylindrical shell considering nanocomposite core and piezoelectric layers subjected to thermal and magnetic fields显示文摘The bending and free vibration of a rotating sandwich cylindrical shell are analyzed with the consideration of the nanocomposite core and piezoelectric layers subjected to thermal and magnetic fields by use of the first-order shear deformation theory(FSDT) of shells. The governing equations of motion and the corresponding boundary conditions are established through the variational method and the Maxwell equation. The closed-form solutions of the rotating sandwich cylindrical shell are obtained. The effects of geometrical parameters, volume fractions of carbon nanotubes, applied voltages on the inner and outer piezoelectric layers, and magnetic and thermal fields on the natural frequency, critical angular velocity, and deflection of the sandwich cylindrical shell are investigated. The critical angular velocity of the nanocomposite sandwich cylindrical shell is obtained. The results show that the mechanical properties, e.g., Young's modulus and thermal expansion coefficient, for the carbon nanotube and matrix are functions of temperature, and the magnitude of the critical angular velocity can be adjusted by changing the applied voltage. | M.MOHAMMADIMEHR R.ROSTAMI | 2018 | Applied Mathematics and Mechanics(English Edition)2018，39，2： | 6 |
| 12 | Optimization of Pass Schedule in Hot Strip Rolling显示文摘Rolling schedule not only determines the rolling process to be going smoothly, but also affects the shape accuracy and structure properties of finished strip. In order to gain good strip crown and flatness, the calculation formulas of the most suitable rolling force and bending force are deduced. By taking relatively equal load of rolling power and good shape as objective functions, the optimization mathematical models of finish rolling schedule are established. By contrast, the rolling schedules after optimization can improve the rolling mill working status and ensure the strip crown and flatness to be good. At the same time, the setting value of bending force is improved and this leaves more space for on-line shape control. | QI Xiang-dong, WANG Tao, XIAO Hong (National Engineering Research Center for Equipment and Technology of Cold Strip Rolling, Yanshan University, Qinhuangdao 066004, Hebei, China) | 2012 | Journal of Iron and Steel Research(International)2012，19，8： | 5 |
| 13 | Aerodynamics and mechanisms of elementary morphing models for flapping wing in forward flight of bat显示文摘Large active wing deformation is a significant way to generate high aerodynamic forces required in bat's flapping flight. Besides the twisting, elementary morphing models of a bat wing are proposed, including wing-bending in the spanwise direction,wing-cambering in the chordwise direction, and wing area-changing. A plate of aspect ratio 3 is used to model a bat wing, and a three-dimensional unsteady panel method is used to predict the aerodynamic forces. It is found that the cambering model has great positive influence on the lift, followed by the area-changing model and then the bending model. Further study indicates that the vortex control is a main mechanism to produce high aerodynamic forces. The mechanisms of aerodynamic force enhancement are asymmetry of the cambered wing and amplification effects of wing area-changing and wing bending. Lift and thrust are generated mainly during downstroke, and they are almost negligible during upstroke by the integrated morphing model-wing. | Ziwu GUAN Yongliang YU | 2015 | Applied Mathematics and Mechanics(English Edition)2015，36，5： | 5 |
| 14 | Texture tailoring and bendability improvement of rolled AZ31 alloy using {10-12} twinning: The effect of precompression levels显示文摘In this study,the texture of a rolled Mg alloy is effectively modified through the application of precompression and subsequent annealing treatment,leading to a remarkable improvement in the bending formability of the alloy at room temperature.Precompression induces lattice reorientation through{10-12}twinning,and annealing treatment reduces the stored strain energy of the precompressed material,which results in the formation of a stable grain structure with two dominant texture components.With an increase in precompression,the tensile strain in the outer region of the bending samples is accommodated to a greater extent due to more pronounced{10-12}twinning and basal slip.As a result,the bending formability of the material at room temperature improves with greater precompression.The variation in microstructure,texture,and bending behavior in relation to the degree of precompression is discussed in detail. | Jong Un Lee Ye Jin Kim Sang-Hoon Kim Jeong Hun Lee Min-Seong Kim Shi-Hoon Choi Byoung Gi Moon Young Min Kim Sung Hyuk Park | 2019 | Journal of Magnesium and Alloys2019，7，4： | 5 |
| 15 | Dynamic rock tensile strengths of Laurentian granite: Experimental observation and micromechanical model显示文摘Tensile strength is an important material property for rocks. In applications where rocks are subjected to dynamic loads, the dynamic tensile strength is the controlling parameter. Similar to the study of static tensile strength, there are various methods proposed to measure the dynamic tensile strength of rocks.Here we examine dynamic tensile strength values of Laurentian granite(LG) measured from three methods: dynamic direct tension, dynamic Brazilian disc(BD) test, and dynamic semi-circular bending(SCB). We found that the dynamic tensile strength from direct tension has the lowest value, and the dynamic SCB gives the highest strength at a given loading rate. Because the dynamic direct tension measures the intrinsic rock tensile strength, it is thus necessary to reconcile the differences in strength values between the direct tension and the other two methods. We attribute the difference between the dynamic BD results and the direct tension results to the overload and internal friction in BD tests. The difference between the dynamic SCB results and the direct tension results can be understood by invoking the non-local failure theory. It is shown that, after appropriate corrections, the dynamic tensile strengths from the two other tests can be reduced to those from direct tension. | Kaiwen Xia Wei Yao Bangbiao Wu | 2017 | Journal of Rock Mechanics and Geotechnical Engineering2017，9，1： | 5 |
| 16 | Mesoscale fracture behavior of Longmaxi outcrop shale with different bedding angles:Experimental and numerical investigations显示文摘The mechanical properties and fracturing mechanism of shale containing beddings are critically important in shale gas exploitation and wellbore stability.To investigate the effects of shale bedding on crack behavior and fracturing mechanism,scanning electron microscope(SEM)with a loading system was employed to carry out three-point bending tests on Longmaxi outcrop shale.The crack initiation and propagation of Longmaxi shale were observed and recorded by taking photos during loading.The cracking paths were extracted to calculate the crack length through a MATLAB program.The peak load,fracture toughness and fracture energy all increase with the bedding angle from 0°to 90°.The crack length and energy were also found to increase with the bedding angle in the range of 0°-600 and then drop slightly.The fracturing mechanism of shale includes the main crack affected by the bedding angle and disturbed by randomly distributed particles.The main cracking path was accompanied by several microcrack branches which could form an interconnected crack system.When the main crack encounters larger sedimentary particles,it will deflect around the particles and then restore to the initial direction.A numerical technique using extended finite element method(XFEM)coupled with anisotropic cohesive damage criteria was developed,which is able to capture the dependence of crack propagations on bedding angle and sedimentary particles.This study sheds light on understanding and predicting mesoscale fracture behavior of shale with different bedding angles. | Jianping Zuo Jingfang Lu Rojin Ghandriz Jintao Wang Yanhong Li Xiaoyan Zhang Jun Li Hongtao Li | 2020 | Journal of Rock Mechanics and Geotechnical Engineering2020，12，2： | 4 |
| 17 | THE METHOD OF THE RECIPROCAL THEOREM OF FORCED VIBRATION FOR THE ELASTIC THIN RECTANGULAR PLATES(Ⅰ)—RECTANGULAR PLATES WITH FOUR CLAMPED EDGES AND WITH THREE CLAMPED EDGES显示文摘In this paper the method of the reciprocal theorem(MRT)is extended to solve thesteady state responses of rectangular plates under harmonic disturbing forces.A series ofthe closed solutions of rectangular plates with various boundary conditions are given andthe tables and figures which have practical value are provided.MRT is a simple,convement and general method for solving the steady state responsesof rectangular plates under vartous harmonic disturbing forces.The paper contains three parts:(Ⅰ)rectangular plates with four clamped edges andwith three clamped edges:(Ⅱ)rectangular.plates with two adjacent clamped edges:(Ⅲ)cantilever plates.We are going to publish them one after another. | 付宝连 李农 | 1989 | Applied Mathematics and Mechanics(English Edition)1989，10，8： | 4 |
| 18 | Inhomogeneous strain-induced half-metallicity in bent zigzag graphene nanoribbons显示文摘Realization of half-metallicity in low dimensional materials is a fundamental challenge for nano spintronics,which is a critical component for next-generation information technology.Using the method of generalized Bloch theorem,we show that an in-plane bending can induce inhomogeneous strains,which in turn lead to spin-splitting in zigzag graphene nanoribbons and results in the highly desired half-metallic state.Unlike the previously proposed scheme that requires unrealistically strong external electric fields,the obtained half-metallicity with sizeable half-metallic gap and high energetic stability of magnetic order of edge states requires only relatively low-level strain in the in-plane bending.Given the superior structural flexibility of graphene and the recent experimental advances in controllable synthesis of graphene nanoribbons,our design provides a hitherto most practical approach to the realization of half-metallicity in low dimensional systems.This work,thus paves a way towards the design of nanoscale spintronic devices through strain engineering. | Dong-Bo Zhang Su-Huai Wei | 2017 | npj Computational Materials2017，，1： | 4 |
| 19 | Study on Bending of Woven Fabrics Using Linear Viscoelasticity Theory显示文摘The bending behavior of woven fabrics under low curva-ture conditions has been analyzed by linear viscoelastictheory.The fabric is assumed to behave viscoelasticallyand to be subjected to frictional restraints in bending de-formation.The frictional restraint is considered to beproportional to the curvature and can be described by africtional moment.A model has been constructed by astandard three-element solid model and a paralleledfrictional sliding element.The equations of the model fora cyclic curvature variation are derived.A set of param-eters of the equations for each fabric has been obtainedexperimentally.Predictions of the bending rigidity andhysteresis for wool,cashmere,wool/polyester blended,polyester and cotton fabrics are made,displaying verygood agreement with the experimental observations. | 石风俊 胡金莲 余同希 | 2000 | Journal of China Textile University(English Edition)2000，17，1： | 4 |
| 20 | Analysis of lateral stability of I-section aluminum beams显示文摘This paper focuses on the lateral buckling of laterally-unrestrained aluminum beams subjected to a concentrated, uniformly loading and pure-bending action. The design methods of lateral stability of aluminum beams in the current codes are discussed. The influence of material property on the lateral buckling of aluminum beams is investigated with finite element analysis (FEA) methods. Some numerical examples are given, and the results from current codes are compared with the FEA solutions. The design method on lateral stability of steel beams specified in the Chinese standard GB 50017-2003 is modified to calibrate the stability factors of aluminum beams according to the European code, British code, and American code, and the modified method is verified by FEA results. Through comparison with the available test results, the modified design method for overall stability of aluminum bending members is proposed in this paper and proved applicable in the design of lateral stability of aluminum beams. | CHENG Ming SHI Yongjiu WANG Yuanqing | 2006 | Science China(Technological Sciences)2006，49，6： | 4 |
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