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圆塑瓶大输液自动包装生产设备的设计与应用 被引量:1
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作者 秦玉超 方超 《机电信息》 2018年第14期13-16,共4页
从圆塑瓶大输液生产线人工包装的工艺流程及缺点入手,提出了将圆塑瓶大输液生产线的人工包装改造为自动包装的方案,介绍了自动包装方案的工艺流程及设计要点,改造后的自动包装生产线经实际运行证明,企业的生产效率及经济效益得到了显著... 从圆塑瓶大输液生产线人工包装的工艺流程及缺点入手,提出了将圆塑瓶大输液生产线的人工包装改造为自动包装的方案,介绍了自动包装方案的工艺流程及设计要点,改造后的自动包装生产线经实际运行证明,企业的生产效率及经济效益得到了显著提升。 展开更多
关键词 圆塑瓶大输液 自动包装 设备布置 理论产能
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库木吐喇石窟千手眼大悲像再探--以伯希和探险队拍摄编号AP 7086历史照片为中心 被引量:1
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作者 刘韬 《艺术设计研究》 CSSCI 2022年第3期11-15,共5页
本文以伯希和探险队拍摄编号AP 7086历史照片为中心,对库木吐喇石窟千手眼大悲像做进一步考订。首先,将AP 7086所摄图像比定为库木吐喇窟群区第7窟主室正壁。其次,推测AP 7086所摄图像与库木吐喇石窟已发现的千手眼大悲像,同属龟兹回鹘... 本文以伯希和探险队拍摄编号AP 7086历史照片为中心,对库木吐喇石窟千手眼大悲像做进一步考订。首先,将AP 7086所摄图像比定为库木吐喇窟群区第7窟主室正壁。其次,推测AP 7086所摄图像与库木吐喇石窟已发现的千手眼大悲像,同属龟兹回鹘时期。再次,分析龟兹回鹘时期千手眼大悲像的样式与造像技艺,兼具龟兹与汉地的双重影响。最后,讨论在中心柱窟正壁以千手眼大悲像为主尊统摄全窟,呈现出龟兹回鹘时期当地独有的图像布局。 展开更多
关键词 库木吐喇石窟 龟兹回鹘 千手眼大悲像 圆塑
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Influences of strain softening and seepage on elastic and plastic solutions of circular openings in nonlinear rock masses 被引量:12
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作者 杨小礼 黄阜 《Journal of Central South University》 SCIE EI CAS 2010年第3期621-627,共7页
Considering the influence of strain softening, the solutions of stress, displacement, plastic softening region radius and plastic residual region radius were derived for circular openings in nonlinear rock masses subj... Considering the influence of strain softening, the solutions of stress, displacement, plastic softening region radius and plastic residual region radius were derived for circular openings in nonlinear rock masses subjected to seepage. The radial stress distribution curve, ground reaction curve, and relation curve between plastic softening region radius and supporting force in three different conditions were drawn respectively. From the comparisons among these results for different conditions, it is found that when the supporting force is the same, the displacement of tunnel wall considering both seepage and strain softening is 85.71% greater than that only considering seepage. The increase values of radial displacement at 0.95 m and plastic softening region radius at 6.6 m show that the seepage and strain softening have the most unfavorable effects on circular opening stability in strain softening rock masses. 展开更多
关键词 strain softening SEEPAGE nonlinear yield ground reaction curve rock masses
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Elasto-plastic Analysis of Circular Tunnels in Jointed Rock Masses Satisfy the Hoek-Brown Failure Criterion 被引量:11
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作者 SUN Jin-shan LU Wen-bo ZHU Qi-hu CHEN Ming 《Journal of China University of Mining and Technology》 EI 2007年第3期393-398,共6页
The relationship between the Hoek-Brown parameters and the mechanical response of circular tunnels is il-lustrated. Closed-form and approximate solutions are given for the extent of the plastic zone and the stress and... The relationship between the Hoek-Brown parameters and the mechanical response of circular tunnels is il-lustrated. Closed-form and approximate solutions are given for the extent of the plastic zone and the stress and dis-placement fields under axisymmetrical and asymmetric stress conditions. For the same rock masses and under axisym-metrical stress conditions,the radius of the plastic zone in terms of Hoek-Brown criterion is generally an approximation of the radius in terms of the Mohr-Coulomb criterion. The radius in terms of the Hoek-Brown criterion is larger under low stress conditions. For poor quality rock masses (GSI<25),measures (such as grouting,setting rock bolts,etc.) that improve the GSI of rock masses are effective in improving the stability of tunnels. It is not advisable to improve the sta-bility of the tunnels by providing a small support resistance p through shotcrete,except for very poor quality jointed rock masses. Without reference to the quality of the rock mass,the disturbance factor D should not less than 0.5. Meas-ures which disturb rock masses during tunnel construction should be taken carefully when the tunnel depth increases. 展开更多
关键词 jointed rock masses circular tunnel general Hoek-Brown failure criterion elasto-plastic analysis con-struction measures
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Viscoelasto-plastic rheological experiment under circular increment step load and unload and nonlinear creep model of soft rocks 被引量:21
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作者 赵延林 曹平 +2 位作者 王卫军 万文 刘业科 《Journal of Central South University》 SCIE EI CAS 2009年第3期488-494,共7页
The viscoelastic-plastic creep experiments on soft ore-rock in Jinchuan Mine III were performed under circular increment step load and unload. The experimental data were analyzed according to instantaneous elastic str... The viscoelastic-plastic creep experiments on soft ore-rock in Jinchuan Mine III were performed under circular increment step load and unload. The experimental data were analyzed according to instantaneous elastic strain, visco-elastic strain, instantaneous plastic strain and visco-plastic strain. The result shows that instantaneous deformation modulus tends to increase with the increase of creep stress; soft rocks enhance the ability to resist instantaneous elastic deformation and instantaneous plastic deformation during the multi-level of load and unload in the cyclic process. In respect of specimen JC1099, the ratio of visco-elastic strain to visco-plastic strain varies from 3.15 to 6.58, and the ratio has decreasing tendency with stress increase as a whole; creep deformation tends to be a steady state at low stress level; soft rocks creep usually embodies accelerated creep properties at high stress level. With the damaging variable and the hardening function introduced, a nonlinear creep model of soft rocks is established, in which the decay creep is described by the nonlinear hardening function H of viscidity coefficient. The model can describe the accelerated creep of soft rocks since the nonlinear damaging evolvement variable D of deformation parameter of rocks is introduced. Three stages of soft rocks creep can be described with the uniform creep equation in the nonlinear creep model. With this nonlinear creep model applied to the creep experiments of the ore-rock of Jinchuan Mine III, the nonlinear creep model's curves are in good agreement with experimental data. 展开更多
关键词 rheological experiment nonlinear creep damaging HARDENING soft rocks
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Investigation of weld parameters on ductility, onion ring and fracture behaviour of friction stir welded AA2219-T87 被引量:2
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作者 Dinesh KUMAR R S MUTHUKUMARAN +2 位作者 Vincent XAVIER T VENKATESWARAN D SIVAKUMAR 《Journal of Central South University》 SCIE EI CAS CSCD 2019年第9期2318-2327,共10页
Friction stir welding provides better retention of ductility and plasticity in comparison to fusion welding and it increases the stability against cracking.This study aims to enhance both the ductility and strength of... Friction stir welding provides better retention of ductility and plasticity in comparison to fusion welding and it increases the stability against cracking.This study aims to enhance both the ductility and strength of the welded joints.Tool profile was found to play an important role in retaining ductility,understanding the metal flow behavior and determining the fracture initiating point.The microstructure of different regions in the onion ring was inferred to correlate the strength with the metal flow pattern.The onion ring pattern strengthened the weld nugget.Shoulder and taper threaded profile tool resulted in superior mechanical properties.Microhardness results confirmed that the fracture runs through low hardness areas such as heat affected zone and thermo-mechanically affected zone.The scanning electron microscopic images revealed elongated grains and dimples,justifying ductile mode of fracture. 展开更多
关键词 plasticity metal flow onion ring fracture friction stir welding
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ELASTOPLASTIC ANALYSIS OF THICK-WALLCYLINDER CONSIDERING THE MATERIAL'S DILATANCY CHARACTER
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作者 江崎哲郎 张铭 +1 位作者 竹下昭博 三谷泰浩 《Journal of China University of Mining and Technology》 1995年第1期66-73,共8页
Impermeable bentonite or its mixtures have been proposed as candidate materials to be used in the geotechnical disposal of radioactive nuclear waste. These materials are filled in the space between a canister containi... Impermeable bentonite or its mixtures have been proposed as candidate materials to be used in the geotechnical disposal of radioactive nuclear waste. These materials are filled in the space between a canister containing radioactive nuclear waste and an underground chamber to absorb the radionuclide emitting from the canister and simultaneously retard its migration accompanying the perrneation of underground water to prevent the surrounding environment from po1lution. On the basis of the established elastoplastic strain-hardening mechanical model considering the material’s dilatancy character,the authors carry out the stress-strain analysis of a thick-wa1l cylinder in a plane strain state subJected to a pressure difference between internal and external pressures. The analysis may be expected to be a theoretical basis for developing a coupled shear and permeability test apparatus for conducting a permeability test along a sheared plane in a specimen. The apparatus will be used to study the effects of shear strain on the variation of geotechnical materials’ permeability coefficient in order to evaluate the influence of shear strain caused by nonuniform deformation and/or earthquake on the long-term safety of the disposal system of radioactive nuclear waste. The theoretlcal analysls methods in this paper can be directly spread to the analysis of the deformation and stability of tunnels or roadways driven in soft soils or high moisture-bearing soft rocks. 展开更多
关键词 DILATANCY thick-wall cylinder elastoplastic analysis waste disposal bentonite mixture
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Analysis of complete plasticity assumption for solid circular shaft under pure torsion and calculation of shear stress 被引量:1
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作者 刘光连 黄明辉 +2 位作者 谭青 李显方 刘振 《Journal of Central South University》 SCIE EI CAS 2011年第4期1018-1023,共6页
The distribution of shear stress on the cross-section of plastic metal solid circular shaft under pure torsion yielding, the applicability of complete plastic model assumption and the shear stress formula were researc... The distribution of shear stress on the cross-section of plastic metal solid circular shaft under pure torsion yielding, the applicability of complete plastic model assumption and the shear stress formula were researched. Based on the shear stress formula of circular shaft under pure torsion in elastic stage, the formula of torque in elastic stage and the definition of yield, it is obtained that the yielding stage of plastic metal shaft under pure torsion is only a surface phenomenon of torque-torsion angle relationship, and the distribution of shear stress is essentially different from that of tensile stress when yielding under uniaxial tension. The pure torsion platform-torsion angle and the shape of torque-torsion angle curve cannot change the distribution of shear stress on the shaft cross-section. The distribution of shear stress is still linear with the maximum shear stress ts. The complete plasticity model assumption is not in accordance with the actual situation of shaft under torsion. The experimental strength data of nine plastic metals are consistent with the calculated results of the new limiting strain energy strength theory (LSEST). The traditional yield stress formula for plastic shaft under torsion is reasonable. The shear stress formula based on the plane assumption in material mechanics is applicable for all loaded stages of torsion shaft. 展开更多
关键词 pure torsion YIELD complete plastic model assumption shear stress calculation limiting strain energy strength theory
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Prediction of plastic zone size around circular tunnels in non-hydrostatic stress field 被引量:6
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作者 Behnam Bagheri Fazlollah Soltani Hamid Mohammadi 《International Journal of Mining Science and Technology》 SCIE EI 2014年第1期81-85,共5页
This paper discusses the calculation of plastic zone properties around circular tunnels to rock-masses that satisfy the Hoek–Brown failure criterion in non-hydrostatic condition,and reviews the calculation of plastic... This paper discusses the calculation of plastic zone properties around circular tunnels to rock-masses that satisfy the Hoek–Brown failure criterion in non-hydrostatic condition,and reviews the calculation of plastic zone and displacement,and the basis of the convergence–confinement method in hydrostatic condition.A two-dimensional numerical simulation model was developed to gain understanding of the plastic zone shape.Plastic zone radius in any angles around the tunnel is analyzed and measured,using different values of overburden(four states)and stress ratio(nine states).Plastic zone radius equations were obtained from fitting curve to data which are dependent on the values of stress ratio,angle and plastic zone radius in hydrostatic condition.Finally validation of this equation indicate that results predict the real plastic zone radius appropriately. 展开更多
关键词 Plastic zone radius Convergence-confinement method Non-hydrostatic condition Stress ratio
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Press cutting of thin-walled round pipe for producing curvilinear end
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作者 温彤 陈霞 《Journal of Central South University》 SCIE EI CAS 2012年第2期304-311,共8页
In order to obtain a basic understanding of the unwanted distortions in the pipe wall during the press cutting process, the deformation of a thin-walled round pipe to form a curvilinear end was numerically and experim... In order to obtain a basic understanding of the unwanted distortions in the pipe wall during the press cutting process, the deformation of a thin-walled round pipe to form a curvilinear end was numerically and experimentally studied. Vector analysis was used to study the relationship between the punch shape and the collapse of the cut-end. Stamping experiments on AISI 1020 steel pipe were conducted using different angles a and β defining the shape of the punch. The elasto-plastic finite element method that allows consideration of a ductile fracture was also employed to study the process. The results show that the deformation of the pipe end after press cutting is inβuenced mostly by the shape of the punch. A satisfactory quality of the curvilinear end of the pipe can be obtained if the appropriate geometric parameters of the punch are chosen. The pipe-wall collapse in the upper part of the section is decreased when a and β increase. The recommended values for a and β lie within 30°-50°. The hole on the underside of the punch has less inβuence on the quality of the cut-end, and the wall distortion and the generation of burr on the cut-end can be satisfactorily simulated using the fracture criterion of Brozzo or the normalized criterion of Cockcroft and Latham. 展开更多
关键词 PIPE press cutting vector analysis finite element method
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Influence of stress anisotropy on the cylindrical cavity expansion in undrained elastic-perfectly plastic soil 被引量:4
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作者 ZHOU Hang LIU HanLong +1 位作者 ZHA YaHui YIN Feng 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2018年第3期370-380,共11页
This work presents an analysis of the influence of stress anisotropy on cylindrical cavity expansions in an undrained elastic-perfectly plastic soil. This problem was formulated by assuming a large strain in both the ... This work presents an analysis of the influence of stress anisotropy on cylindrical cavity expansions in an undrained elastic-perfectly plastic soil. This problem was formulated by assuming a large strain in both the elastic and plastic zones around the cavity and a plain strain condition during the cavity expansion process. The solutions for the limit pressure, stress, and excess pore pressure were obtained by introducing the anisotropic initial stress coefficient K_0 into the conventional cylindrical cavity expansion method.The proposed solutions were then used to interpret the piezocone penetration test, and the suitability of the solutions was verified by comparing the prediction with the piezocone penetration test data. Subsequently, parametric studies were carried out to investigate the influence of stress anisotropy on the stress, excess pores pressure distributions around an expanding cylindrical cavity, and limit pressure. The results show that the proposed cylindrical cavity expansion method under stress anisotropy is suitable and can be used to investigate the piezocone cone test. The present work improves upon the conventional theoretical framework of cavity expansion and can be applied to the determination of the stresses around axially loaded piles and around in-situ testing devices such as penetrometers. 展开更多
关键词 anisotropy cylindrical cavity expansion undrained elastic-perfectly plastic
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Effect of weld reinforcement on axial plastic buckling of welded steel cylindrical shells 被引量:3
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作者 Chu-lin YU Zhi-ping CHEN +2 位作者 Ji WANG Shun-juan YAN Li-cai YANG 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2012年第2期79-90,共12页
The effect of weld reinforcement on axial plastic buckling of welded steel cylindrical shells is investigated through experimental and numerical buckling analysis using six welded steel cylindrical shell specimens. Th... The effect of weld reinforcement on axial plastic buckling of welded steel cylindrical shells is investigated through experimental and numerical buckling analysis using six welded steel cylindrical shell specimens. The relationship between the amplitude of weld reinforcement and the axial plastic buckling critical load is explored. The effect of the material yield strength and the number of circumferential welds on the axial plastic buckling is studied. Results show that circumferential weld reinforcement represents a severe imperfect form of axially compressed welded steel cylindrical shells and the axial plastic buckling critical load decreases with the increment of the mean amplitude of circumferential weld reinforcement. The material yield strength and the number of circumferential welds are found to have no significant effect on buckling waveforms; however, the axial plastic buckling critical load can be decreased to some extent with the increase of the number of circumferential welds. 展开更多
关键词 Cylindrical shells Axial buckling PLASTIC WELD REINFORCEMENT Geometric imperfections
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Line field analysis and complex variable method for solving elastic-plastic fields around an anti-plane elliptic hole 被引量:3
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作者 GUO JunHong LU ZiXing 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2011年第8期1495-1501,共7页
A new approach is proposed to solve the elastic-plastic fields near the major-axis line of an elliptical hole. The complex variable method is used to determine the elastic fields near the major-axis line of the ellipt... A new approach is proposed to solve the elastic-plastic fields near the major-axis line of an elliptical hole. The complex variable method is used to determine the elastic fields near the major-axis line of the elliptical hole. Then, by using the line field analysis method, the exact and new solutions of the stresses, strains in the plastic zone, the size of the plastic region and the unit normal vector of the elastic-plastic boundary near the major-axis line of the elliptical hole are obtained for an anti-plane elliptical hole in a perfectly elastic-plastic solid. The usual small scale yielding assumptions are not adopted in the analysis. The present method is simple, easy and efficient. The influences of applied mechanical loading on the size of plastic zone are discussed. 展开更多
关键词 complex variable method line field analysis method elliptical hole elastic-plastic solid
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Simulations of Bingham plastic flows with the multiple-relaxation-time lattice Boltzmann model 被引量:4
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作者 CHEN SongGui SUN QiCheng +1 位作者 JIN Feng LIU JianGuo 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第3期532-540,共9页
Fresh cement mortar is a type of workable paste, which can be well approximated as a Bingham plastic and whose flow behavior is of major concern in engineering. In this paper, Papanastasiou's model for Bingham fluids... Fresh cement mortar is a type of workable paste, which can be well approximated as a Bingham plastic and whose flow behavior is of major concern in engineering. In this paper, Papanastasiou's model for Bingham fluids is solved by using the multiple- relaxation-time lattice Boltzmann model (MRT-LB). Analysis of the stress growth exponent m in Bingham fluid flow simulations shows that Papanastasiou's model provides a good approximation of realistic Bingham plastics for values of m 〉 108. For lower values of m, Papanastasiou's model is valid for fluids between Bingham and Newtonian fluids. The MRT-LB model is validated by two benchmark problems: 2D steady Poiseuille flows and lid-driven cavity flows. Comparing the numerical results of the velocity distributions with corresponding analytical solutions shows that the MRT-LB model is appropriate for studying Bingham fluids while also providing better numerical stability. We further apply the MRT-LB model to simulate flow through a sudden expansion channel and the flow surrounding a round particle. Besides the rich flow structures obtained in this work, the dynamics fhi d force on the round particle is calculated. Results show that both the Reynolds number Re and the Bingham number Bn affect the drag coefficients Co, and a drag coefficient with Re and Bn being taken into account is proposed. The relationship of Bn and the ratio of unyielded zone thickness to particle diameter is also analyzed. Finally, the Bingham fluid flowing around a set of randomly dispersed particles is simulated to obtain the apparent viscosity and velocity fields. These results help simulation of fresh concrete flowing in porous media. 展开更多
关键词 Bingham fluids multiple-relaxation-time lattice Boltzmann model tbw profiles drag coefficient
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