期刊文献+
共找到20篇文章
< 1 >
每页显示 20 50 100
Comparison of large deformation failure control method in a deep gob-side roadway: A theoretical analysis and field investigation
1
作者 WANG Jiong LIU Peng +2 位作者 HE Man-chao LIU Yi-peng DU Chang-xin 《Journal of Mountain Science》 SCIE CSCD 2023年第10期3084-3100,共17页
Under the dual influence of the mining disturbance of the previous working face and the advanced mining of the working face,the roadway is prone to large deformation,failure,and rockburst.Roadway stabilization has alw... Under the dual influence of the mining disturbance of the previous working face and the advanced mining of the working face,the roadway is prone to large deformation,failure,and rockburst.Roadway stabilization has always significantly influenced deep mining safety.In this article we used the research background of the large deformation failure roadway of Fa-er Coal Mine in Guizhou Province of China to propose two control methods:bolt-cable-mesh+concrete blocks+directional energy-gathering blasting(BCM-CBDE method)and 1st Generation-Negative Poisson’s Ratio(1G NPR)cable+directional energy-gathering blasting+dynamic pressure stage support(πgirder+single hydraulic prop+retractable U steel)(NPR-DEDP method).Meantime,we compared the validity of the large deformation failure control method in a deep gob-side roadway based on theoretical analysis,numerical simulations,and field experiments.The results show that directional energy-gathering blasting can weaken the pressure acting on the concrete blocks.However,the vertical stress of the surrounding rock of the roadway is still concentrated in the entity coal side and the concrete blocks,showing a’bimodal’distribution.BCM-CBDE method cannot effectively control the stability of the roadway.NPR-DEDP method removed the concrete blocks.It shows using the 1G NPR cable with periodic slipping-sticking characteristics can adapt to repeated mining disturbances.The peak value of the vertical stress of the roadway is reduced and transferred to the deep part of the surrounding rock mass,which promotes the collapse of the gangue in the goaf and fills the goaf.The pressure of the roadway roof is reduced,and the gob-side roadway is fundamentally protected.Meantime,the dynamic pressure stage support method withπgirder+single hydraulic prop+retractable U steel as the core effectively protects the roadway from dynamic pressure impact when the main roof is periodically broken.After the on-site implementation of NPR-DEDP method,the deformation of the roadway is reduced by more than 45%,and the deformation rate is reduced by more than 50%. 展开更多
关键词 Deep gob-side roadway deformation failure control Roof structure mechanical model Stress field distribution Mining safety .Failure mode.
下载PDF
A generalized multi-field coupling approach and its application to stability and deformation control of a high slope 被引量:5
2
作者 Chuangbing Zhou Yifeng Chen +1 位作者 Qinghui Jiang Wenbo Lu 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE 2011年第3期193-206,共14页
Human activities, such as blasting excavation, bolting, grouting and impounding of reservoirs, will lead to disturbances to rock masses and variations in their structural features and material properties. These engine... Human activities, such as blasting excavation, bolting, grouting and impounding of reservoirs, will lead to disturbances to rock masses and variations in their structural features and material properties. These engineering disturbances are important factors that would alter the natural evolutionary processes or change the multi-field interactions in the rock masses from their initial equilibrium states. The concept of generalized multi-field couplings was proposed by placing particular emphasis on the role of engineering disturbances in traditional multi-field couplings in rock masses. A mathematical model was then developed, in which the effects of engineering disturbances on the coupling-processes were described with changes in boundary conditions and evolutions in thermo-hydro-mechanical (THM) properties of the rocks. A parameter, d, which is similar to damage variables but has a broader physical meaning, was conceptually introduced to represent the degree of engineering disturbances and the couplings among the material properties. The effects of blasting excavation, bolting and grouting in rock engineering were illustrated with various field observations or theoretical results, on which the degree of disturbances and the variations in elastic moduli and permeabilities were particularly focused. The influences of excavation and groundwater drainage on the seepage flow and stability of the slopes were demonstrated with numerical simulations. The proposed approach was further employed to investigate the coupled hydro-mechanical responses of a high rock slope to excavation, bolting and impounding of the reservoir in the dam left abutment of Jinping I hydropower station. The impacts of engineering disturbances on the deformation and stability of the slope during construction and operation were demonstrated. 展开更多
关键词 generalized multi-field couplings engineering disturbance slope stability deformation control
下载PDF
Sheet Bulk Forming of Thin-Walled Components with External Gearing through Upsetting Using Controllable Deformation Zone Method 被引量:1
3
作者 Xincun Zhuang Meile Liang +2 位作者 Shengfa Zhu Yin Zhu Zhen Zhao 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2021年第5期282-295,共14页
Sheet-bulk metal forming(SBMF)is a promising process for manufacturing complex sheet components with functional elements.In this study,the entire forming process for a typical thin-walled component with external geari... Sheet-bulk metal forming(SBMF)is a promising process for manufacturing complex sheet components with functional elements.In this study,the entire forming process for a typical thin-walled component with external gearing is investigated,including sheet forming and bulk forming processes.Deep drawn cups are prepared during sheet forming;subsequently,upsetting is performed on the sidewall to form external gearing.The upsetting method performed is known as upsetting with a controllable deformation zone(U-CDZ).Compared with the conventional upsetting method,a floating counter punch with a counter force is used in the U-CDZ method such that the forming mechanism is changed into the accumulation of the deformation zone instead of deformation throughout the entire sidewall.The effects of the counter force and material flow are investigated to understand the mechanism.The forming quality,i.e.,the formfilling and effective strain distribution,improved,whereas a high forming load is avoided.In addition,a punch with a lock bead is used to prevent folding at the inner corner during the experiment. 展开更多
关键词 Sheet-bulk metal forming Thin-walled components External gearing controllable deformation zone
下载PDF
Weld deformation control based on programmable multi-point flexible support 被引量:2
4
作者 Xiao Jun Lei Yiding +2 位作者 Chen Shujun Lu Wei He Enguang 《China Welding》 CAS 2022年第3期30-34,共5页
T-joint titanium alloy structures are commonly used in aircraft manufacturing,and their laser welding process is relatively mature,but due to the strict requirements of the airplane production,the angular deformation ... T-joint titanium alloy structures are commonly used in aircraft manufacturing,and their laser welding process is relatively mature,but due to the strict requirements of the airplane production,the angular deformation caused by uneven heat input across the sheet is still not negligible,so active control needs to be imposed.In this paper,an active deformation control method based on programmable multi-point flexible support is proposed and validated.In response to the problem that the traditional rigid clamping and pre-stressing are not adapted to the T-structure thin sheet,this study has designed a multi-point flexible support with microcontroller and electric actuators,which can monitor the stress state of the current support position in real time during the welding process and make dynamic adjustment,so that the weld deformation could be effectively reduced in this way. 展开更多
关键词 laser welding deformation control flexible support force control
下载PDF
Top-coal deformation control of gob-side entry with narrow pillars and its application for fully mechanized mining face 被引量:3
5
作者 Qi Fangkun Zhou Yuejin +3 位作者 Li Jiawei Wang Erqian Cao Zhengzheng Li Ning 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2016年第3期417-422,共6页
A mechanical model to control the top-coal deformation is established in accordance with the structural characters of the gob-side entry surrounding rock for the fully-mechanic top-coal caving; the analytical solution... A mechanical model to control the top-coal deformation is established in accordance with the structural characters of the gob-side entry surrounding rock for the fully-mechanic top-coal caving; the analytical solution of top coal roof-sag curve is deduced with Winkler elastic foundation beam model. By means of a calculating and analytic program, the top coal roof-sag values are calculated under the conditions of different supporting intensities, widths of narrow pillars and stiffness of top coal; meanwhile, the relationship between the roof-sag values and supporting intensity, width of narrow pillars and stiffness of top coal is analyzed as well. With the actual situation of the gob-side entry taken into consideration, the parameters of top-coal control are determined and a supporting plan is proposed for the top-coal control,which is proved to be reliable and effective by on-site verification. Some theoretical guidance and advice are put forward for the top-coal deformation control in gob-side entry for fully mechanized top-coal caving face. 展开更多
关键词 Fully mechanized top-coal caving Narrow pillar Gob-side entry Top coal deformation control
下载PDF
Reinforcement learning method for machining deformation control based on meta-invariant feature space
6
作者 Yujie Zhao Changqing Liu +2 位作者 Zhiwei Zhao Kai Tang Dong He 《Visual Computing for Industry,Biomedicine,and Art》 EI 2022年第1期323-339,共17页
Precise control of machining deformation is crucial for improving the manufacturing quality of structural aerospace components.In the machining process,different batches of blanks have different residual stress distri... Precise control of machining deformation is crucial for improving the manufacturing quality of structural aerospace components.In the machining process,different batches of blanks have different residual stress distributions,which pose a significant challenge to machining deformation control.In this study,a reinforcement learning method for machining deformation control based on a meta-invariant feature space was developed.The proposed method uses a reinforcement-learning model to dynamically control the machining process by monitoring the deformation force.Moreover,combined with a meta-invariant feature space,the proposed method learns the internal relationship of the deformation control approaches under different stress distributions to achieve the machining deformation control of different batches of blanks.Finally,the experimental results show that the proposed method achieves better deformation control than the two existing benchmarking methods. 展开更多
关键词 Machining deformation Residual stress deformation control Meta-invariant feature space Reinforcement learning
下载PDF
Deformation Control of Deep Excavation Pit and Numerical Simulation with Finite Element Method
7
作者 Li Yun’an Engineering Faculty, China University of Geosciences, Wuhan 430074 School of Civil Engineering and Mechanics, Shanghai Jiaotong University, Shanghai 200030 Ge Xiurun School of Civil Engineering and Mechanics, Shanghai Jiaotong University, Shanghai 200030 Tang Huiming Engineering Faculty, China University of Geosciences, Wuhan 430074 《Journal of China University of Geosciences》 SCIE CSCD 2002年第3期278-288,共11页
The authors firstly introduce deformation control of deep excavation pit indetail, and then put forward new conceptions such as: effective coefficient of excavation pit,effective area, ineffective area and critical li... The authors firstly introduce deformation control of deep excavation pit indetail, and then put forward new conceptions such as: effective coefficient of excavation pit,effective area, ineffective area and critical line, and also put forward the referential criteria ofdeformation control. The System of Optimization Design with Deformation Control of Deep ExcavationPit and Numerical Simulation with Finite Element Method (SDCDEFEM) is also briefly introduced.Factors influencing deformation of excavation pit are analyzed by the system. The measured andsimulated data of maximum deformations (settlement, displacement and upheaval) and their positionsare analyzed and discussed. The statistic formula estimating maximum deformations and theirpositions was gained, and economical-effective measures of deformation control were brought forward. 展开更多
关键词 deep excavation pit deformation control finite element effectivecoefficient of excavation pit
下载PDF
Research on Deformation Control Indicators and Standard of Urban Traffic Tunnel Construction Adjacent to High-rise Building
8
作者 Bo Shi Kun Wang Ke Li 《Journal of Architectural Research and Development》 2020年第6期24-30,共7页
The biggest environmental problem caused by the construction of tunnels adjacent to high-rise buildings is the settlement of buildings.The paper analyzes the influence of tunnel excavation on the deformation of the su... The biggest environmental problem caused by the construction of tunnels adjacent to high-rise buildings is the settlement of buildings.The paper analyzes the influence of tunnel excavation on the deformation of the superstructure and the deformation mode of the superstructure.It introduces the indicators and standards for the construction control of tunnel adjacent to the building at home and abroad.Combined with the Yuzhong tunnel project under construction in Chongqing,the main monitoring indicators and control standards of the Yuzhong Tunnel passing through the main buildings are given after comprehensive analysis and considerations,which provide a reference for the deformation control indicators of similar urban traffic tunnels adjacent to high-rise buildings. 展开更多
关键词 deformation control Indicators Urban Traffic Tunnel Construction High-rise Building
下载PDF
Tunnel entrance crossing spoil heap deformations control by micropile combine with coupling beams
9
作者 Chunwei Wu Han Xia +1 位作者 Da Qin Junhui Luo 《Geohazard Mechanics》 2024年第1期21-28,共8页
Aiming at the deformation control problem of the tunnel entrance crossing the spoil heap at the Xialao junction,this paper adopts the micropile combined with the coupling beams method to treat the spoiled layers.The r... Aiming at the deformation control problem of the tunnel entrance crossing the spoil heap at the Xialao junction,this paper adopts the micropile combined with the coupling beams method to treat the spoiled layers.The results show that the excavation of the tunnel after the construction of the micropile and coupling beam will cause vertical deformation of the tunnel and the slope surface.The main reason is that the soil layer structure is loose,and the tunnel excavation causes the whole displacement of the loose body.In addition,the buried depth of the tunnel is shallow,so it cannot form an effective soil arch.The stability process after the construction of the micropile method is the process of stress redistribution,and the rock and soil are gradually compressed and compacted.That is,the construction by the micropile method changes the surrounding rock level of the tunnel and reduces the height of the soil arch.Therefore,it is suggested that the tunnel excavation should be carried out when the micropile is constructed after the soil layers are consolidated completely.The micropile method treats the loose spoiled soil at the tunnel entrance,which saves 73%of the total cost compared with the scheme of directly digging out the accumulation,and the economic benefit is very obvious. 展开更多
关键词 MICROPILE Coupling beams Spoil heap deformation control
原文传递
Floor heave characteristics and control technology of the roadway driven in deep inclined-strata 被引量:7
10
作者 Wang Meng Guo Guanlong +2 位作者 Wang Xiangyu Guo Yu Dao Vietdoan 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第2期267-273,共7页
Based on in-mine instrumentation and theoretical analysis of the unsymmetrical large-deformation that occurred in the roadway after excavation,Differential Floor Heave(DFH)was found to be the main reason for roadway f... Based on in-mine instrumentation and theoretical analysis of the unsymmetrical large-deformation that occurred in the roadway after excavation,Differential Floor Heave(DFH)was found to be the main reason for roadway failure.It needs to be pointed out that the specific roadway was driven in inclined rock strata.In addition,the factors that contribute to the occurrence of DFH are discussed in detail.It is believed that DFH is triggered by the unsymmetrical stress distribution in the floor and the different rock types encountered near the two floor corners.Hence,DFH control should be focused on the left floor corner where shearing failure occurs initially and the left floor surface where tensile failure is more severe.The proposed DFH control strategies include unsymmetrical grouting for the whole roadway,re-design of the roof and ribs support,reinforcement of the weak zones,and release of the concentrated stress in the earlier stage.Meanwhile,it is recommended that in the later stage,both bolts and cable bolts with higher strength and the backfilling technique using the coal measure rocks and concrete should be employed in the reversed-arch floor.The field instrumentation results,after using the proposed control strategies,indicate that large deformation in a DFH roadway has been successfully controlled. 展开更多
关键词 Deep roadway Inclined strata Differential Floor Heave (DFH)Unsymmetrical deformation Two stage control strategies
下载PDF
High-resistance controlled yielding supporting technique in deep-well oil shale roadways 被引量:3
11
作者 Yu Yang Bai Jianbiao +3 位作者 Wang Xiangyu Wang Junde Xue Shizhi Xu Ke 《International Journal of Mining Science and Technology》 SCIE EI 2014年第2期229-236,共8页
In order to avoid the deep-well oil shale roadway being deformed, damaged, or difficult to maintain after excavating and supporting in Haishiwan coal mine, this paper has analyzed the characteristics of the deformed r... In order to avoid the deep-well oil shale roadway being deformed, damaged, or difficult to maintain after excavating and supporting in Haishiwan coal mine, this paper has analyzed the characteristics of the deformed roadway and revealed its failure mechanism by taking comprehensively the methods of field geological investigation, displacement monitoring of surrounding rock, rock properties and hydration properties experiments and field application tests. Based on this work, the high-resistance controlled yielding supporting principle is proposed, which is: to "resist" by high pre-tightening force and high stiff- ness in the early stage, to "yield" by making use of the controlled deformation of a yielding tube in the middle stage, and to "fix" by applying total-section Gunite in the later stage. A high-resistance controlled yielding supporting technique of "high pre-tightening force yielding anchor bolt + small-bore pre-tight- ening force anchor cable + rebar ladder beam + rhombic metal mesh + lagging gunite" has been estab- lished, and industrial on site testing implemented. The practical results show that the high-resistance controlled yielding supporting technique can effectively control the large deformation and long-time rheology of deep-well oil shale roadways and can provide beneficial references for the maintenance of other con-generic roadways.Deep-well Oil shale 展开更多
关键词 deformation failure mechanism High-resistance controlled yielding supporting Yielding anchor bolt
下载PDF
Deformation control criterion of shield tunnel under lateral relaxation of soft soil 被引量:1
12
作者 Shimin WANG Xiaoyu PENG +3 位作者 Hang ZHOU Xuhu HE Anqi ZHOU Bing CHEN 《Frontiers of Structural and Civil Engineering》 SCIE EI CSCD 2023年第5期780-795,共16页
Metro shield tunnels under the lateral relaxation of soil(LRS)are susceptible to significant lateral deformations,which jeopardizes the structural safety and waterproofing.However,deformation control standards for suc... Metro shield tunnels under the lateral relaxation of soil(LRS)are susceptible to significant lateral deformations,which jeopardizes the structural safety and waterproofing.However,deformation control standards for such situations have not been clearly defined.Therefore,based on a specific case,a model test is conducted to realize the LRS of a shield tunnel in a sandy stratum to reveal its effect on segment liners.Subsequently,a deformation control criterion is established.The LRS is simulated by linearly reducing the loads applied to the lateral sides of the segment structure.During lateral unloading,the lateral earth pressure coefficient on the segment decreases almost exponentially,and the structural deformation is characterized by horizontal expansion at the arch haunches and vertical shrinkage at the arch vault and arch bottom.Based on the mechanical pattern of the segment structure and the acoustic emission,the deformation response of a segment can be classified into three stages:elastic and quasi-elastic,damage,and rapid deformation development.For a shield tunnel with a diameter of approximately 6 m and under the lateral relaxation of sandy soil,when the ellipticity of the segment is less than 2.71%,reinforcement measures are not required.However,the segment deformation must be controlled when the ellipticity is 2.71%to 3.12%;in this regard,an ellipticity of 3%can be used as a benchmark in similar engineering projects. 展开更多
关键词 shield tunnel lateral relaxation of soil deformation control criterion of segment structure model test
原文传递
Deep Learning Applied to Computational Mechanics:A Comprehensive Review,State of the Art,and the Classics 被引量:1
13
作者 Loc Vu-Quoc Alexander Humer 《Computer Modeling in Engineering & Sciences》 SCIE EI 2023年第11期1069-1343,共275页
Three recent breakthroughs due to AI in arts and science serve as motivation:An award winning digital image,protein folding,fast matrix multiplication.Many recent developments in artificial neural networks,particularl... Three recent breakthroughs due to AI in arts and science serve as motivation:An award winning digital image,protein folding,fast matrix multiplication.Many recent developments in artificial neural networks,particularly deep learning(DL),applied and relevant to computational mechanics(solid,fluids,finite-element technology)are reviewed in detail.Both hybrid and pure machine learning(ML)methods are discussed.Hybrid methods combine traditional PDE discretizations with ML methods either(1)to help model complex nonlinear constitutive relations,(2)to nonlinearly reduce the model order for efficient simulation(turbulence),or(3)to accelerate the simulation by predicting certain components in the traditional integration methods.Here,methods(1)and(2)relied on Long-Short-Term Memory(LSTM)architecture,with method(3)relying on convolutional neural networks.Pure ML methods to solve(nonlinear)PDEs are represented by Physics-Informed Neural network(PINN)methods,which could be combined with attention mechanism to address discontinuous solutions.Both LSTM and attention architectures,together with modern and generalized classic optimizers to include stochasticity for DL networks,are extensively reviewed.Kernel machines,including Gaussian processes,are provided to sufficient depth for more advanced works such as shallow networks with infinite width.Not only addressing experts,readers are assumed familiar with computational mechanics,but not with DL,whose concepts and applications are built up from the basics,aiming at bringing first-time learners quickly to the forefront of research.History and limitations of AI are recounted and discussed,with particular attention at pointing out misstatements or misconceptions of the classics,even in well-known references.Positioning and pointing control of a large-deformable beam is given as an example. 展开更多
关键词 Deep learning breakthroughs network architectures backpropagation stochastic optimization methods from classic to modern recurrent neural networks long short-term memory gated recurrent unit attention transformer kernel machines Gaussian processes libraries Physics-Informed Neural Networks state-of-the-art history limitations challenges Applications to computational mechanics Finite-element matrix integration improved Gauss quadrature Multiscale geomechanics fluid-filled porous media Fluid mechanics turbulence proper orthogonal decomposition Nonlinear-manifold model-order reduction autoencoder hyper-reduction using gappy data control of large deformable beam
下载PDF
Study on gob-side entry retaining in fully-mechanized longwall with top-coal caving and its application 被引量:13
14
作者 Su Hai Bai Jianbiao +2 位作者 Yan Shuai Chen Yong Zhang Zizheng 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2015年第3期503-510,共8页
Based on the engineering background of gob-side entry retaining in fully-mechanized longwall with top coal caving(GER-FLTC) on N2105 working face of Yuwu coal mine, by adopting the methods of theoretical analysis and ... Based on the engineering background of gob-side entry retaining in fully-mechanized longwall with top coal caving(GER-FLTC) on N2105 working face of Yuwu coal mine, by adopting the methods of theoretical analysis and numerical calculation, the control techniques of surrounding rocks in GER-FLTC working face are studied in this paper. The two main difficulties of stability of surrounding rocks at gob-side retained entry in fully-mechanized longwall working face are the stability control of top coal and control of large deformation of GER-FLTC working face. Interaction mechanical model between roofing and roadside backfilling in GER-FLTC is established and the equations for the calculation of roof-cutting resistance of roadside backfilling are derived. Results of numerical calculation show that the damage zones of top coal can be categorized into the delaminating zone of top coal above the backfilling, tensile damage zone of top coal above the retained roadway and shear damage zone of the upper rib of the solid coal. Stability control of top coal is the critical part to success of GER-FLTC. With consideration of large deformation of surrounding rocks of gob-side retained entry in fully-mechanized longwall, the support technique of‘‘roofing control and wall strengthening'' is proposed where high strength and highly prestressed anchor rods and diagonal tensile anchor cables support are used for top coal, high strength and highly prestressed yielding anchor rod support is used for solid coal and roadside prestressed load-carrying backfilling is constructed by high-water material, in order to maintain the integrity of the top coal, transfer load, high resistance yielding load-carrying of solid coal, roof-cutting of roadside backfilling and support,and to achieve GER-FLTC. Results from this study are successfully applied in engineering practice. 展开更多
关键词 Gob-side entry retaining in fully-mechanized longwan with top coal caving Stability control of top coalLarge deformation control Roofing control and wall strengthening
下载PDF
An improved constrained steering law for SGCMGs with DPC 被引量:1
15
作者 Lei Jin Shijie Xu Department of Guidance, Navigation and Control,School of Astronautics, Beihang University, 100191 Beijing, China 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2009年第5期713-720,共8页
An improved constrained (IC) steering law for single gimbal control moment gyros (SGCMGs) with deformed pyramid configuration (DPC) is proposed, First of all, the original system with five pyramid configuration ... An improved constrained (IC) steering law for single gimbal control moment gyros (SGCMGs) with deformed pyramid configuration (DPC) is proposed, First of all, the original system with five pyramid configuration (FPC) whose two adjacent gyros are in failure state is reconfigured as a degraded system with DPC. Then, the singular angular momentum hypersurfaces of the original and the degraded systems are plotted via the singular angular momentum equa- tion of SGCMGs. Based on singular surfaces, the differences between FPC and DPC in singularity and momentum envelope are obtained directly, which provide an important reference for steering law design of DPC. Finally, an IC steering law is designed and applied to DPC. The simulation results demonstrate that the IC steering law has advantages in simplicity of calculation, avoidance of singularity and exactness of output torque, which endow the degraded system with fine controllability in a restricted workspace. 展开更多
关键词 Single gimbal control moment gyros (SGCMGs) - Deformed pyramid configuration (DPC) Failure Singularity - Steering law
下载PDF
Thermally controlled large deformation in temperaturesensitive hydrogels bilayers
16
作者 Jianying Hu Nan Jiang Jianke Du 《International Journal of Smart and Nano Materials》 SCIE EI 2021年第4期450-471,共22页
The present work investigates the thermally controlled deformation characteristics in temperature-sensitive hydrogels bilayers.The free energy density for temperature-sensitive hydrogels is modified,upon which the fin... The present work investigates the thermally controlled deformation characteristics in temperature-sensitive hydrogels bilayers.The free energy density for temperature-sensitive hydrogels is modified,upon which the finite element model is developed and implemented through user-defined material subroutine UHYPER in the commercial software ABAQUS.The modified UHYPER implementation allows for more vividly depicting the continuous deformation in phase temperature region for temperature-sensitive hydrogels.Several thermally controlled cases of temperature-sensitive hydrogel including grippers,self-folding boxes,thermally driven origami are presented to illustrate a wide array of complex interesting applications or phenomena.Furthermore,we develop a simple model to theoretically calculate the bending angle of the temperature-sensitive hydrogel bilayers,which has been validated by the finite element simulation results.Our study can provide more insights for optimal design in thermally controlled hydrogels structures. 展开更多
关键词 Temperature-sensitive hydrogels thermally controlled deformation swelling-induced bending
原文传递
An allowance allocation method based on dynamic approximation via online inspection data for deformation control of structural parts
17
作者 Xiaozhong HAO Yingguang LI +3 位作者 Chong HUANG Mengqiu LI Changqing LIU Kai TANG 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2020年第12期3495-3508,共14页
Deformation resulting from residual stress has been a significant issue in machining.As allowance allocation can directly impact the residual stress on part deformation,it is essential for deformation control.However,... Deformation resulting from residual stress has been a significant issue in machining.As allowance allocation can directly impact the residual stress on part deformation,it is essential for deformation control.However,it is difficult to adjust allowance allocation by traditional simulation methods based on residual stress,as the residual stress cannot be accurately measured or predicted,and many unexpected factors during machining process cannot be simulated accurately.Different from traditional methods,this paper proposes an allowance allocation method based on dynamic approximation via online inspection data for deformation control of structural parts.An Autoregressive Integrated Moving Average(ARIMA)model for dynamic allowance allocation is established so as to approach the minimum deformation,which is based on the in-process deformation inspection data during the alternative machining process of upside and downside.The effectiveness of the method is verified both by simulation cases and real machining experiments of aircraft structural parts,and the results show that part deformation can be significantly reduced. 展开更多
关键词 ARIMA model deformation control deformation inspection data Machining allowance allocation Structural parts
原文传递
3D Printing of Stretchable Strain Sensor Based on Continuous Fiber Reinforced Auxetic Structure
18
作者 Wanquan Yan Xiaoyong Tian +2 位作者 Daokang Zhang Yanli Zhou Qingrui Wang 《Chinese Journal of Mechanical Engineering(Additive Manufacturing Frontiers)》 2023年第2期11-18,共8页
Stretchable strain sensors play a key role in motion detection and human-machine interface functionality,and deformation control.However,their sensitivity is often limited by the Poisson effect of elastic substrates.I... Stretchable strain sensors play a key role in motion detection and human-machine interface functionality,and deformation control.However,their sensitivity is often limited by the Poisson effect of elastic substrates.In this study,a stretchable strain sensor based on a continuous-fiber-reinforced auxetic structure was proposed and fabricated using a direct ink writing(DIW)3D printing process.The application of multi-material DIW greatly simplifies the fabrication process of a sensor with an auxetic structure(auxetic sensor).The auxiliary auxetic struc-ture was innovatively printed using a continuous-fiber-reinforced polydimethylsiloxane composite(Fiber-PDMS)to balance the rigidity and flexibility of the composite.The increase in stiffness enhances the negative Poisson’s ratio effect of the auxetic structure,which can support the carbon nanotube-polydimethylsiloxane composite(CNT-PDMS)stretchable sensor to produce a significant lateral expansion when stretched.It is shown that the structural Poisson’s ratio of the sensor decreased from 0.42 to−0.33 at 20%tensile strain,and the bidirectional tensile strain increases the sensor sensitivity by 2.52 times(gage factor to 18.23).The Fiber-PDMS composite maintains the excellent flexibility of the matrix material.The auxetic sensor exhibited no structural damage af-ter 150 cycles of tension and the signal output exhibited high stability.In addition,this study demonstrates the significant potential of auxetic sensors in the field of deformation control. 展开更多
关键词 3D printing Stretchable sensor Auxetic structure Continuous fiber Sensitivity deformation control
原文传递
Numerical study on lateral wall displacement of deep excavation supported by IPS earth retention system 被引量:2
19
作者 Tugen Feng Long Liu +1 位作者 Tao Tong Mi Zhou 《Underground Space》 SCIE EI 2017年第4期259-271,共13页
The objective of this study is to investigate the 3D behavior characteristics of an excavation supported by an innovative prestressed support(IPS)earth retention system.A numerical simulation was conducted in order to... The objective of this study is to investigate the 3D behavior characteristics of an excavation supported by an innovative prestressed support(IPS)earth retention system.A numerical simulation was conducted in order to provide insight into the IPS system behavior by using the FLAC3D package.Prior to the parametric study,validation work was conducted by means of a comparison of the deformation between thefield test data and numerical analysis results,and strong agreement was obtained.The reasonable excavation location,lay-ered excavation thickness,and blocked excavation sequence are presented according to variable parameter analysis.In view of the pre-viousfindings,certain measurements are proposed in order to control the foundation pit deformation.The results indicate that prestress compensation has a significant effect on the IPS system behavior,while an optimized excavation sequence slightly improves its behavior.With the conclusion proposed based on the numerical results,the aim is to provide reference data for optimization design and the construction sequence. 展开更多
关键词 FLAC3D IPS system Prestress compensation Layered excavation Blocked excavation deformation control
原文传递
Manipulating a micro-cantilever between its optomechanical bistable states in a lever-based Fabry-Pérot cavity 被引量:1
20
作者 FU Hao DING JiangFang +1 位作者 LI Yong CAO GengYu 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS CSCD 2015年第5期41-45,共5页
In this paper, we demonstrate experimentally switching a cantilever between its optomechanical bistable states in a low finesse optical cavity. Our experiment shows that the deformation of cantilever can be manipulate... In this paper, we demonstrate experimentally switching a cantilever between its optomechanical bistable states in a low finesse optical cavity. Our experiment shows that the deformation of cantilever can be manipulated by tuning the cavity resonance. When the laser power increases across the threshold value of 110 ?W, optomechanical bistability is induced by strong static photothermal backaction at room temperature. Numerical calculation revealed that the bistable effect originates from the multi-well potential created via the optomechanical interaction. Switching of the cantilever between the bistable states was achieved by tuning the cavity to the corresponding boundaries of the bistable region, where the barrier between the bistable states vanishes. 展开更多
关键词 optomechanical bistability static deformation control optomechanical switch photothermal backaction MICRO-CANTILEVER
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部