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Distributed Fiber Optic Monitoring and Stability Analysis of a Model Slope under Surcharge Loading 被引量:23
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作者 ZHU Hong-Hu SHI Bin +2 位作者 ZHANG Jie YAN Jun-Fan ZHANG Cheng-Cheng 《Journal of Mountain Science》 SCIE CSCD 2014年第4期979-989,共11页
In the discipline of geotechnical engineering, fiber optic sensor based distributed monitoring has played an increasingly important role over the past few decades. Compared with conventional sensors, fiber optic senso... In the discipline of geotechnical engineering, fiber optic sensor based distributed monitoring has played an increasingly important role over the past few decades. Compared with conventional sensors, fiber optic sensors have a variety of exclusive advantages, such as smaller size, higher precision, and better corrosion resistance. These innovative monitoring technologies have been successfully applied for performance monitoring of geo-structures and early warning of potential geo- hazards around the world. In order to investigate their ability to monitor slope stability problems, a medium-sized model of soil nailed slope has been constructed in laboratory. The fully distributed Brillouin optical time-domain analysis (BOTDA) sensing technology was employed to measure the horizontal strain distributions inside the model slope. During model construction, a specially designed strain sensing fiber was buried in the soil mass. Afterward, the surcharge loading was applied on the slope crest in stages using hydraulic jacks and a reaction frame. During testing, an NBX-6o5o BOTDA sensing interrogator was used to collect the fiber optic sensing data. The test results have been analyzed in detail, which shows that the fiber optic sensors can capture the progressive deformation and failure pattern of the model slope. The limit equilibrium analyses were also conducted to obtain the factors ofsafety of the slope under different surface loadings. It is found that the characteristic maximum strains can reflect the stability of the model slope and an empirical relationship was obtained, This study verified the effectiveness of the distributed BOTDA sensing technology in performance monitoring of slope. 展开更多
关键词 Slope stability Geotechnical monitoring fiber optic sensor Distributed strain sensing Brillouin optical time-domain analysis (BOTDA) model test
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Micro Model of Carbon Fiber/Cyanate Ester Composites and Analysis of Machining Damage Mechanism 被引量:3
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作者 Haitao Liu Jie Lin +1 位作者 Yazhou Sun Jinyang Zhang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第3期198-208,共11页
Machining damage occurs on the surface of carbon fiber reinforced polymer (CFRP) composites during processing. In the current simulation model of CFRP, the initial defects on the carbon fiber and the periodic random d... Machining damage occurs on the surface of carbon fiber reinforced polymer (CFRP) composites during processing. In the current simulation model of CFRP, the initial defects on the carbon fiber and the periodic random distribution of the reinforcement phase in the matrix are not considered in detail, which makes the characteristics of the cutting model significantly different from the actual processing conditions. In this paper, a novel three-phase model of carbon fiber/cyanate ester composites is proposed to simulate the machining damage of the composites. The periodic random distribution of the carbon fiber reinforced phase in the matrix was realized using a double perturbation algorithm. To achieve the stochastic distribution of the strength of a single carbon fiber, a novel method that combines the Weibull intensity distribution theory with the Monte Carlo method is presented. The mechanical properties of the cyanate matrix were characterized by fitting the stress-strain curves, and the cohesive zone model was employed to simulate the interface. Based on the model, the machining damage mechanism of the composites was revealed using finite element simulations and by conducting a theoretical analysis. Furthermore, the milling surfaces of the composites were observed using a scanning electron microscope, to verify the accuracy of the simulation results. In this study, the simulations and theoretical analysis of the carbon fiber/cyanate ester composite processing were carried out based on a novel three-phase model, which revealed the material failure and machining damage mechanism more accurately. 展开更多
关键词 Carbon fiber reinforced polymer COMPOSITES MICRO simulation model MACHINING damage mechanism MILLING and observation experiment Theoretical analysis
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Seismic response of continuous span bridges through fiber-based finite element analysis 被引量:9
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作者 Chiara Casarotti Rui Pinho 《Earthquake Engineering and Engineering Vibration》 SCIE EI CSCD 2006年第1期119-131,共13页
It is widely recognized that nonlinear time-history analysis constitutes the most accurate way to simulate the response of structures subjected to strong levels of seismic excitation. This analytical method is based o... It is widely recognized that nonlinear time-history analysis constitutes the most accurate way to simulate the response of structures subjected to strong levels of seismic excitation. This analytical method is based on sound underlying principles and has the capability to reproduce the intrinsic inelastic dynamic behavior of structures. Nonetheless, comparisons with experimental results from large-scale testing of structures are still needed, in order to ensure adequate levels of confidence in this numerical methodology. The fiber modelling approach employed in the current endeavor inherently accounts for geometric nonlinearities and material inelasticity, without a need for calibration of plastic hinges mechanisms, typical in concentrated plasticity models. The resulting combination of analysis accuracy and modelling simplicity, allows thus to overcome the perhaps not fully justifiable sense of complexity associated to nonlinear dynamic analysis. The fiber-based modelling approach is employed in the framework of a finite element program downloaded from the Intemet for seismic response analysis of framed structures. The reliability and accuracy of the program are demonstrated by numerically reproducing pseudo-dynamic tests on a four span continuous deck concrete bridge. Modelling assumptions are discussed, together with their implications on numerical results of the nonlinear time-history analyses, which were found to be in good agreement with experimental results. 展开更多
关键词 BRIDGES seismic response pseudo-dynamic testing nonlinear dynamic analysis fiber modelling
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Simulation and Analysis of Fiber Motion in Condensing Zone of Compact Spinning with Lattice Apron 被引量:3
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作者 汪燕 华志宏 +1 位作者 程隆棣 袁力军 《Journal of Donghua University(English Edition)》 EI CAS 2010年第5期600-605,共6页
To get fiber motion in condensing zone of compact spinning,velocity of this area is achieved by simulation,and then a bead-elastic rod fiber model is established.Based on simulation and dynamic analysis on this zone,g... To get fiber motion in condensing zone of compact spinning,velocity of this area is achieved by simulation,and then a bead-elastic rod fiber model is established.Based on simulation and dynamic analysis on this zone,governing equations are constructed and Runge-Kutta approach is used.Lastly,trajectories of fibers are calculated by specially designed Matlab procedure according to the principles mentioned above.Results show that fiber motions at different initial positions are different;X-axis velocity component makes fibers gathering on sides of suction slot;Y-axis airflow gets fibers gradually close and then stick to the surface of lattice apron.Fiber motions also reflect that the compact spinning process in condensing zone can be divided into three parts:fast convergence zone,adjustment convergence zone,and steady convergence zone. 展开更多
关键词 compact spinning with lattice apron fiber model kinetic analysis simulation of flow field fiber motion compact mechanism
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Modeling of fiber bridging in fluid flow for well stimulation applications 被引量:5
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作者 Mehdi Ghommem Mustapha Abbad +2 位作者 Gallyam Aidagulov Steve Dyer Dominic Brady 《Petroleum Science》 SCIE CAS CSCD 2020年第3期671-686,共16页
Accurate acid placement constitutes a major concern in matrix stimulation because the acid tends to penetrate the zones of least resistance while leaving the low-permeability regions of the formation untreated.Degrada... Accurate acid placement constitutes a major concern in matrix stimulation because the acid tends to penetrate the zones of least resistance while leaving the low-permeability regions of the formation untreated.Degradable materials(fibers and solid particles)have recently shown a good capability as fluid diversion to overcome the issues related to matrix stimulation.Despite the success achieved in the recent acid stimulation jobs stemming from the use of some products that rely on fiber flocculation as the main diverting mechanism,it was observed that the volume of the base fluid and the loading of the particles are not optimized.The current industry lacks a scientific design guideline because the used methodology is based on experience or empirical studies in a particular area with a particular product.It is important then to understand the fundamentals of how acid diversion works in carbonates with different diverting mechanisms and diverters.Mathematical modeling and computer simulations are effective tools to develop this understanding and are efficiently applied to new product development,new applications of existing products or usage optimization.In this work,we develop a numerical model to study fiber dynamics in fluid flow.We employ a discrete element method in which the fibers are represented by multi-rigid-body systems of interconnected spheres.The discrete fiber model is coupled with a fluid flow solver to account for the inherent simultaneous interactions.The focus of the study is on the tendency for fibers to flocculate and bridge when interacting with suspending fluids and encountering restrictions that can be representative of fractures or wormholes in carbonates.The trends of the dynamic fiber behavior under various operating conditions including fiber loading,flow rate and fluid viscosity obtained from the numerical model show consistency with experimental observations.The present numerical investigation reveals that the bridging capability of the fiber–fluid system can be enhanced by increasing the fiber loading,selecting fibers with higher stiffness,reducing the injection flow rate,reducing the suspending fluid viscosity or increasing the attractive cohesive forces among fibers by using sticky fibers. 展开更多
关键词 fiber bridging fiber flocculation modeling and numerical simulation Discrete element method fiber-fluid coupling Sensitivity analysis
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Simulation Tools for a Fiber-Optic Based Structural Health Monitoring System 被引量:2
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作者 Alfredo Güemes Antonio Fernandez-Lopez +2 位作者 Jaime García-Ramírez Maria Eugenia Reyes-Perez Flor Criado Zurita 《Transactions of Nanjing University of Aeronautics and Astronautics》 EI CSCD 2018年第2期219-225,共7页
Probability of detection(POD)graphics allow for a change from qualitative to quantitative assessment for every damage detection system,and as such it is a main request for conventional non-destructive testing(NDT)tech... Probability of detection(POD)graphics allow for a change from qualitative to quantitative assessment for every damage detection system,and as such it is a main request for conventional non-destructive testing(NDT)techniques.Its availability can greatly help towards the industrialization of the corresponding Structural health monitoring(SHM)system.But having in mind that for SHM systems the sensors are at fixed positions,and the location of a potential damage would change its detectability.Consequently robust simulation tools are required to obtain the model assisted probability of detection(MAPOD)which is needed to validate the SHM system.This tool may also help for the optimization of the sensor distribution,and finally will allow a probabilistic risk management.INDEUS,simulation of ultrasonic waves SHM system,was a main milestone in this direction.This article deals with the simulation tools for a strain based SHM system,using fiber optic sensors(FOS).FOS are essentially strain/temperature sensors,either with multi-point or with distributed sensing.The simulation tool includes the finite element model(FEM)for the original and damaged structure,and algorithms to compare the strain data at the pre-established sensors locations,and from this comparison to extract information about damage occurrence and location.The study has been applied to the structure of an all-composite unmanned aircraft vehicle(UAV)now under construction,designed at Universidad Politecnica de Madrid for the inspection of electrical utilities networks.Distributed sensing optical fibers were internally bonded at the fuselage and wing.Routine inspection is planned to be done with the aircraft at the test bench by imposing known loads.From the acquired strain data,damage occurrence may be calculated as slight deviations from the baselines.This is a fast inspection procedure without requiring trained specialists,and it would allow for detection of hidden damages.Simulation indicates that stringer partial debondings are detected before they become critical,while small delaminations as those produced by barely visible impact damages would require a prohibited number of sensing lines.These simulation tools may easily be applied to any other complex structure,just by changing the FEM models.From these results it is shown how a fiber optic based SHM system may be used as a reliable damage detection procedure. 展开更多
关键词 damage DETECTION fiber optics distributed sensing finite element models probability of detection(POD) principal component analysis (PCA) FIBRE BRAGG GRATINGS (FBG)
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Nonlinear stability of timber column strengthened with fiber reinforced polymer
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作者 欧阳煜 杨骁 包若涵 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2011年第7期903-916,共14页
By taking into account the effect of the bi-modulus for tension and compression of the fiber reinforced polymer (FRP) sheet in the reinforcement layer, a general mathematical model for the nonlinear bending of a sle... By taking into account the effect of the bi-modulus for tension and compression of the fiber reinforced polymer (FRP) sheet in the reinforcement layer, a general mathematical model for the nonlinear bending of a slender timber beam strengthened with the FRP sheet is established under the hypothesis of the large deflection deformation of the beam. Nonlinear governing equations of the second order effect of the beam bending are derived. The nonlinear stability of a simply-supported slender timber column strengthened with the FRP sheet is then investigated. An expression of the critical load of the simply-supported FRP-strengthened timber beam is obtained. The existence of postbuckling solution of the timber column is proved theoretically, and an asymptotic analytical solution of the postbuckling state in the vicinity of the critical load is obtained using the perturbation method. Parameters are studied showing that the FRP reinforcement layer has great influence on the critical load of the timber column, and has little influence on the dimensionless postbuckling state. 展开更多
关键词 fiber reinforced polymer (FRP) timber column REINFORCEMENT bi-modulus nonlinear mathematical model postbuckling analysis
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Modeling and analysis of actively Q-switched Fe:ZnSe laser pumped by a 2.8μm fiber laser
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作者 LIANG Xiaolin ZHOU Songqing +1 位作者 LIU Zhizhuang BAO Bengang 《Optoelectronics Letters》 EI 2023年第9期513-518,共6页
A theoretical model concerning active Q-switching of an Fe:ZnSe laser pumped by a continuous-wave(CW)2.8μm fiber laser is developed.Calculations are compared with the recently reported experiment results,and good agr... A theoretical model concerning active Q-switching of an Fe:ZnSe laser pumped by a continuous-wave(CW)2.8μm fiber laser is developed.Calculations are compared with the recently reported experiment results,and good agreement is achieved.Effects of principal parameters,including pump power,output reflectivity,ion concentration and temperature of crystal,on the laser output performance are investigated and analyzed.Numerical results demonstrate that similar to highly efficient CWFe:ZnSe laser,low temperature of the crystal is significant to obtain high peak power Q-switched pulses.The numerical simulation results are useful for optimizing the design of actively Q-switched Fe:ZnSe laser. 展开更多
关键词 modeling and analysis of actively Q-switched Fe:ZnSe laser pumped by a 2.8μm fiber laser
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温度影响下碳纤维导线分层力学特性有限元分析 被引量:1
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作者 祝贺 袁鸣 郭鑫 《西南交通大学学报》 EI CSCD 北大核心 2024年第3期700-711,共12页
为探明温度对碳纤维导线分层力学特性的影响,考虑拐点温度,利用电热模块施加不同电压得到多种温度,并计算分析不同温度和拉断力条件下碳纤维导线的各层、各股和各截面应力应变分布.研究结果表明:拐点温度后,碳芯受到正向应力但铝绞线承... 为探明温度对碳纤维导线分层力学特性的影响,考虑拐点温度,利用电热模块施加不同电压得到多种温度,并计算分析不同温度和拉断力条件下碳纤维导线的各层、各股和各截面应力应变分布.研究结果表明:拐点温度后,碳芯受到正向应力但铝绞线承受负向应力,使碳纤维导线失去了承担拉断力的作用;各股线的最大应力和应变均出现在线的两端,倒角位置的应力和应变结果略大于对应股线主体上的应力;碳纤维导线各个截面的最大应力均为正值,均出现在碳芯上,其靠近外力施加端截面的最大应力出现突然下降的现象;碳纤维导线更适用于各种温度条件,但应注意导线两端夹持位置和梯形截面中小截面的力学特性变化. 展开更多
关键词 碳纤维导线 温度效应 分层力学 温度-力学模型 有限元仿真
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正交异性钢-钢纤维混凝土组合桥面板疲劳极限状态研究
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作者 叶华文 潘威洲 +2 位作者 何建希 叶杨帆 邓雪峰 《桥梁建设》 EI CSCD 北大核心 2024年第4期46-52,共7页
为了解正交异性钢-钢纤维混凝土(Steel Fiber Reinforced Concrete,SFRC)组合桥面板的疲劳性能及失效机理,以川南城际铁路临港长江大桥为背景,设计、制作正交异性钢-SFRC组合桥面板足尺模型进行疲劳试验,采用ANSYS软件建立试件有限元模... 为了解正交异性钢-钢纤维混凝土(Steel Fiber Reinforced Concrete,SFRC)组合桥面板的疲劳性能及失效机理,以川南城际铁路临港长江大桥为背景,设计、制作正交异性钢-SFRC组合桥面板足尺模型进行疲劳试验,采用ANSYS软件建立试件有限元模型,研究关键细节的疲劳应力和开裂等情况。基于有限元模型,分析不同设计参数(钢顶板厚度、栓钉布置、SFRC抗拉强度及层厚)下组合桥面板疲劳极限状态的失效模式,并提出了主要控制参数取值建议。结果表明:200万次疲劳加载后足尺模型的实测最大裂缝宽度为0.136 mm,出现在SFRC层上缘,钢结构未开裂,组合桥面板疲劳性能良好;组合桥面板疲劳极限状态主要由SFRC层开裂控制,钢顶板厚度、栓钉布置对组合桥面板疲劳性能的影响较小,SFRC抗拉强度和层厚对组合桥面板疲劳性能影响较大,为主要控制参数;在常规正交异性钢桥面板上铺设薄层(厚度不超过50 mm)SFRC时,SFRC抗拉强度不应小于5 MPa,在常规正交异性钢桥面板上铺设普通SFRC(钢纤维体积含量不高于1%,抗拉强度不高于3 MPa)时,SFRC层厚不宜低于100 mm。 展开更多
关键词 组合桥面板 正交异性钢板 钢纤维混凝土 疲劳失效模式 参数分析 足尺模型试验 有限元法
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BFRP模壳不排水加固RC墩柱恢复力模型
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作者 张景杭 夏樟华 +3 位作者 姜绍飞 洪俊贤 朱朴 范千 《振动与冲击》 EI CSCD 北大核心 2024年第16期192-203,共12页
为研究玄武岩纤维增强聚合物(basalt fiber reinforced polymer, BFRP)模壳不排水加固钢筋混凝土(reinforced concrete, RC)墩柱抗震恢复力模型,在拟静力试验基础上,采用OpenSees有限元软件对模壳加固墩柱进行数值分析,主要研究参数为... 为研究玄武岩纤维增强聚合物(basalt fiber reinforced polymer, BFRP)模壳不排水加固钢筋混凝土(reinforced concrete, RC)墩柱抗震恢复力模型,在拟静力试验基础上,采用OpenSees有限元软件对模壳加固墩柱进行数值分析,主要研究参数为填充层混凝土强度、模壳厚度、加固高度、轴压比。研究表明:填充层混凝土强度等级越高,墩柱抗震性能有所增强,但C40以上的填充层混凝土强度等级墩柱的抗震性能较为接近;模壳加固厚度较大墩柱的抗震性能优于厚度较小墩柱;当模壳加固高度较高时,墩柱的抗震性能较好,当加固高度大于2~3倍原墩柱塑性铰高度时,抗震性能提升效果趋于稳定;轴压比越大,墩柱的刚度退化较快,不利延性发展。后通过数据回归分析,建立了BFRP模壳加固RC墩柱恢复力模型,对比可知,恢复力模型与试验曲线拟合较好,能有效反映加固墩柱的滞回性能,可为此类结构的抗震性能分析提供参考。 展开更多
关键词 玄武岩纤维增强聚合物(BFRP)模壳 不排水加固 钢筋混凝土(RC)墩柱 有限元 参数分析 恢复力模型
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轴压下FRP管-混凝土-钢管组合柱可靠性分析
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作者 高海洋 王连广 陈百玲 《东北大学学报(自然科学版)》 EI CAS CSCD 北大核心 2024年第3期430-438,共9页
以85个FRP管-混凝土-钢管双壁空心柱(double-skin tubular column,DSTC)轴压试验数据作为统计样本,评估了几种现有FRP约束混凝土强度模型,最终选择Teng模型进行可靠性分析,并确定了强度模型误差和构件抗力的最佳概率分布.运用JC法对DST... 以85个FRP管-混凝土-钢管双壁空心柱(double-skin tubular column,DSTC)轴压试验数据作为统计样本,评估了几种现有FRP约束混凝土强度模型,最终选择Teng模型进行可靠性分析,并确定了强度模型误差和构件抗力的最佳概率分布.运用JC法对DSTC进行可靠度计算.结果表明:可靠指标随着钢管强度、中空率和含钢率的提高而升高,而对混凝土强度的变化不敏感.FRP约束应力的增加会导致可靠指标的下降.基于可靠指标目标3.7,提出一个适用于DSTC的抗力分项系数表达式. 展开更多
关键词 DSTC 强度模型 可靠性分析 JC法 抗力分项系数 FRP
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基于纤维形态的结构功能特性模拟研究进展 被引量:1
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作者 孔繁康 李静 +2 位作者 沙力争 童欣 郭大亮 《中国造纸》 CAS 北大核心 2024年第6期165-174,共10页
本文总结了计算机模拟技术在纤维形态模拟中的应用研究进展,并在此基础上分析了多种纤维材料的可视化技术及性能预测与对比,以期为实现纤维在材料中的定位模拟研究和功能材料的开发提供思考。
关键词 纤维 材料性能 模拟理论 三维模型建立 可视化分析
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玄武岩纤维尾砂充填体力学性能及损伤本构模型 被引量:1
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作者 任碧琦 徐振洋 +2 位作者 王雪松 魏可心 张祚富 《有色金属工程》 CAS 北大核心 2024年第1期108-118,共11页
为了提高采空区充填体的力学性能,对加入玄武岩纤维的尾砂充填体进行抗压强度试验,研究不同纤维掺量、灰砂比和养护龄期对充填体的抗压强度影响规律,构建充填体损伤本构模型并分析其能量耗散规律。结果表明:玄武岩纤维的加入能够明显提... 为了提高采空区充填体的力学性能,对加入玄武岩纤维的尾砂充填体进行抗压强度试验,研究不同纤维掺量、灰砂比和养护龄期对充填体的抗压强度影响规律,构建充填体损伤本构模型并分析其能量耗散规律。结果表明:玄武岩纤维的加入能够明显提高尾砂充填体的抗压强度,随着纤维掺量的增加,充填体的抗压强度呈先增大后减小的趋势,且最优掺量为0.4%,对比素尾砂充填体强度提升了13.277%~24.865%。纤维充填体峰后残余强度较高,引入损伤修正系数的损伤本构模型能合理表述纤维充填体峰后残余强度,根据损伤本构模型可得到充填体的峰值比能演算模型,适量掺加纤维可以提升充填体的峰值比能并减少能量耗散。玄武岩纤维能提高充填体的力学性能,强化矿山采空区充填效果。 展开更多
关键词 玄武岩纤维尾砂充填体 抗压强度 损伤本构模型 能量分析
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碳纤维增强复合布加固混凝土圆柱受压承载力试验与数值模拟
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作者 周月明 高婧 +1 位作者 宋怀辉 许志旭 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第4期724-733,共10页
[目的]对不同层数碳纤维增强复合(CFRP)布加固混凝土圆柱进行轴心抗压试验的破坏分析以筛选出最优层数,并在此基础上对混凝土强度及长细比参数作进一步分析.[方法]采用万能试验机对不同层数CFRP布加固混凝土圆柱试件进行轴压试验,同时利... [目的]对不同层数碳纤维增强复合(CFRP)布加固混凝土圆柱进行轴心抗压试验的破坏分析以筛选出最优层数,并在此基础上对混凝土强度及长细比参数作进一步分析.[方法]采用万能试验机对不同层数CFRP布加固混凝土圆柱试件进行轴压试验,同时利用ABAQUS非线性有限元软件进行模拟验证及参数分析.[结果]轴压试验结果的极限承载力及荷载-位移曲线表明,CFRP布加固混凝土圆柱对于提升混凝土的抗压承载力具有明显效果,同时对于C30混凝土而言,两层CFRP布的加固效果最优.有限元模拟结果得出随着混凝土强度的提升,CFRP布的加固效率降低;当长细比大于2∶1时,CFRP布加固混凝土圆柱对于偏心受压时极限承载力的提升较小.[结论]本文通过对不同层数CFRP布加固混凝土圆柱试件进行轴压试验分析,筛选出了最优加固层数.同时提出了相应的有限元模型,其与试验结果吻合良好.基于有限元模型对混凝土强度及试件长细比参数进行充分分析,为CFRP布加固混凝土圆柱在实际工程应用中提供了参考依据. 展开更多
关键词 碳纤维增强复合(CFRP) 轴压试验 模型验证 有限元分析
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基于纤维梁柱单元的古建筑木柱空间受力分析模型
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作者 吴亚杰 孟威 +3 位作者 王燚 许阳 谢启芳 张利朋 《西安建筑科技大学学报(自然科学版)》 北大核心 2024年第5期723-729,共7页
古建筑木柱浮搁于础石,其空间力学性能与结构地震响应密切相关.提出了基于纤维梁柱单元的古建筑木柱空间受力分析模型,根据柱脚局部受压确定古建筑木柱纤维截面网格尺寸划分原则,使用只压材料反映古建筑木柱受压不受拉特性,通过设置材... 古建筑木柱浮搁于础石,其空间力学性能与结构地震响应密切相关.提出了基于纤维梁柱单元的古建筑木柱空间受力分析模型,根据柱脚局部受压确定古建筑木柱纤维截面网格尺寸划分原则,使用只压材料反映古建筑木柱受压不受拉特性,通过设置材料应变间隙考虑柱底与础石的接触缺陷.分析了模型对材性参数和应变间隙的敏感性,给出了模型应变间隙的取值方法,并基于已有试验验证了模型的正确性.进一步对模型施加空间荷载和地震机理,获取了其空间力和位移特性,结果表明:模型具备反映古建筑木柱空间力学性能的能力,可应用于结构抗震分析. 展开更多
关键词 古建筑木柱 空间力学性能 分析模型 纤维梁柱单元 接触缺陷
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新型FRP-金属组合T型梁桥及扭转刚度简化计算方法的研究 被引量:1
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作者 莫昌金 袁辉 +1 位作者 孙峰 杨军 《建筑结构》 北大核心 2024年第1期59-65,78,共8页
基于应急桥梁的轻量化、高强化和模块化的发展需求,提出了一种模块化纤维增强复合材料(FRP)-金属组合T型梁桥。首先,介绍了该T型梁桥的结构尺寸、空间布置、杆件类型、连接方式以及现场快速架设方法。其次,基于开口、闭口薄壁截面杆扭... 基于应急桥梁的轻量化、高强化和模块化的发展需求,提出了一种模块化纤维增强复合材料(FRP)-金属组合T型梁桥。首先,介绍了该T型梁桥的结构尺寸、空间布置、杆件类型、连接方式以及现场快速架设方法。其次,基于开口、闭口薄壁截面杆扭转理论,推导了该T型梁桥结构扭转刚度简化计算公式。最后,基于通用软件ANSYS开展了有限元分析,利用所推导的简化计算公式进行了结构扭转刚度影响因素分析。结果表明:相较于传统单车道钢结构应急桥梁,该组合T型梁桥达到了明显的减重效果;结构扭转刚度理论计算值与有限元值吻合较好,所建立的理论简化计算模型可便于单片T型梁扭转刚度的预测;单片T型梁的外扭矩主要由各纵向构件和斜腹杆共同抵抗。 展开更多
关键词 桥梁工程 T型梁 理论分析 扭转刚度 纤维增强复合材料 有限元模型 应急桥梁
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基于网格模型的自动铺丝路径规划方法
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作者 张铭雨 周鹏 +1 位作者 范长好 陈杰 《纤维复合材料》 CAS 2024年第3期113-121,共9页
针对复合材料自动铺丝工艺,研究基于网格模型的自动铺丝路径规划方法。梳理了自动铺丝路径规划的业务流程,对三角网格拓扑关系进行重建,节省数据存储空间;提出了基于给定点与方向的定向延伸算法,用于精确计算网格模型的线型路径点;对路... 针对复合材料自动铺丝工艺,研究基于网格模型的自动铺丝路径规划方法。梳理了自动铺丝路径规划的业务流程,对三角网格拓扑关系进行重建,节省数据存储空间;提出了基于给定点与方向的定向延伸算法,用于精确计算网格模型的线型路径点;对路径等距后的点集进行优化,避免了等距后的线型自交以及凸边现象,保证了线型的准确;对所规划路径的压辊可铺放性分析方法进行研究,并基于分析结果提出了路径优化策略。结合CATIA二次开发工具CAA在VS平台对自动铺丝路径规划模块进行开发,并通过实例验证了本文所研究方法的可行性与可靠性。 展开更多
关键词 自动铺丝 三角网格模型 路径规划 可铺放性分析 CATIA
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Thermogravimetric analysis of bamboo-tar under different heating rates based on distributed activation energy model
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作者 Huan Zhang Beibei Yan +4 位作者 Tingzhou Lei Tao Liu Jianjun Hu Yameng Li Guanyi Chen 《International Journal of Agricultural and Biological Engineering》 SCIE EI CAS 2018年第6期180-186,共7页
Carbon fiber is a kind of new polymer material with excellent mechanical properties and being applied widely.The process of carbon fiber prepared by bamboo tar,including extraction,condensation,spinning,oxidation and ... Carbon fiber is a kind of new polymer material with excellent mechanical properties and being applied widely.The process of carbon fiber prepared by bamboo tar,including extraction,condensation,spinning,oxidation and carbonation,is influenced by the pyrolysis kinetics significantly.In this paper,the thermogravimetric analysis(TGA)of bamboo tar produced in the process of pyrolysis and gasification of the bamboo which is known as Phylostachys sulphurea,was analyzed by the distributed activation energy model(DAEM)to understand the kinetic properties and parameters of bamboo tar.The thermogravimetric analysis of bamboo tar which is used as the raw material of carbon fiber was conducted under 5 different heating rates(i.e.5,10,15,30 and 50℃/min,etc.)in nitrogen atmosphere.The results show that the activation energy of bamboo tar and the exponential factor increased significantly with the increase of the heating rate,and the low heating rate is advantageous to the extraction of bamboo tar solvent and the thermal polycondensation,which can provide scientific reference for the optimization of carbon fiber technology.The thermal weight results show that the temperature range of bamboo tar being decomposed rapidly is 213℃-410℃.The ranges of the activation energy were calculated by DAEM,which have small difference in comparisons with five heating rates when the conversion rate is at 0.1-0.6 and the average value of the activation energy is 119 kJ/mol.The stability range of the activation energy is enlarged when the conversion rate is greater than 0.6 and heating rate increases. 展开更多
关键词 bamboo tar carbon fiber thermogravimetric analysis(TGA) distributed activation energy model(DAEM)
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高烈度震区预制拼装连续刚构桥延性分析
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作者 贾继祥 张雷 《铁路工程技术与经济》 2024年第5期27-31,共5页
本文基于纤维梁柱单元模型的基本原理,对广佛西环城际铁路4×40m预制拼装连续刚构在罕遇地震作用下进行弹塑性分析,结果表明:在10.5~22m墩高范围内,随着墩高增加,塑性转角、剪力计算值有降低的趋势;箍筋对桥墩的延性影响很大,甚至... 本文基于纤维梁柱单元模型的基本原理,对广佛西环城际铁路4×40m预制拼装连续刚构在罕遇地震作用下进行弹塑性分析,结果表明:在10.5~22m墩高范围内,随着墩高增加,塑性转角、剪力计算值有降低的趋势;箍筋对桥墩的延性影响很大,甚至在某种程度依赖于箍筋配置的合理与否,合理的配置箍筋是一种经济有效的提高抗震性能的方式;采用《铁路工程抗震设计规范》和《城市桥梁抗震设计规范》两种方法验算了该种桥梁桥墩的抗震性能,其弹塑性分析方法和延性抗震成果为其他高烈度震区刚构桥延性抗震设计提供了参考。 展开更多
关键词 预制拼装 连续刚构 罕遇地震 纤维模型 时程分析 塑性铰 弹塑性分析
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