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Longbiao Li - One of the best experts on this subject based on the ideXlab platform.
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Time-Dependent Fatigue Behavior of Fiber-Reinforced Ceramic-Matrix Composites at Elevated Temperatures
Advanced Ceramics and Composites, 2020Co-Authors: Longbiao LiAbstract:In this chapter, the time-dependent static fatigue and cyclic fatigue behavior of fiber-reinforced ceramic-matrix composites (CMCs) are investigated. The stress-strain relationships considering Interface oxidation and Interface wear in the Interface debonding region under static and cyclic fatigue loading are developed to establish the relationships between the peak strain, the Interface debonding length, the Interface oxidation length, and the Interface Slip lengths. The effects of the stress-rupture time, stress levels, matrix crack spacing, fiber volume, and oxidation temperature on the peak strain and the Interface Slip lengths are investigated. The experimental fatigue hysteresis loops, Interface Slip lengths, peak strain, and Interface oxidation length of C/[Si–B–C] and SiC/MAS composite at 566, 1093, and 1200 °C in air atmosphere are predicted.
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Synergistic effects of Interface Slip and fiber fracture on stress-dependent mechanical hysteresis of SiC/SiC minicomposites
Composite Interfaces, 2020Co-Authors: Longbiao LiAbstract:ABSTRACTIn this paper, the synergistic effects of Interface Slip and fiber fracture on stress-dependent mechanical hysteresis of SiC/SiC ceramic-matrix minicomposites (mini-CMCs) are investigated. ...
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Tension-tension fatigue behavior of unidirectional SiC/Si3N4 composite with strong and weak Interface bonding at room temperature
Ceramics International, 2017Co-Authors: Longbiao Li, Pascal Reynaud, Gilbert FantozziAbstract:Abstract In this paper, the tension-tension fatigue behavior of unidirectional SiC/Si 3 N 4 ceramic-matrix composite with strong and weak Interface bonding at room temperature has been investigated using a micromechanical approach. The hysteresis loops models considering different Interface Slip cases have been developed to establish the relationships between fatigue hysteresis loops, hysteresis dissipated energy, hysteresis modulus, and the Interface shear stress. The damage evolution process under tension-tension fatigue loading has been analyzed using hysteresis loops. By comparing experimental fatigue hysteresis dissipated energy with theoretical computational values, the Interface shear stresses of SiC/Si 3 N 4 composite with weak and strong Interface bonding were obtained for different cycle numbers. The fatigue life S‒N curves and broken fibers fraction versus cycle number curves corresponding to different fatigue peak stresses have been predicted. For SiC/Si 3 N 4 with strong Interface bonding, the fatigue limit stress approaches to 75% tensile strength, which is much higher than that of composite with weak Interface bonding, i.e., 58% tensile strength, due to the higher Interface shear stress degradation rate for weak bonding Interface.
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Synergistic Effects of Stress-Rupture and Cyclic Loading on Strain Response of Fiber-Reinforced Ceramic-Matrix Composites at Elevated Temperature in Oxidizing Atmosphere.
Materials, 2017Co-Authors: Longbiao LiAbstract:In this paper, the synergistic effects of stress rupture and cyclic loading on the strain response of fiber-reinforced ceramic-matrix composites (CMCs) at elevated temperature in air have been investigated. The stress-strain relationships considering Interface wear and Interface oxidation in the Interface debonded region under stress rupture and cyclic loading have been developed to establish the relationship between the peak strain, the Interface debonded length, the Interface oxidation length and the Interface Slip lengths. The effects of the stress rupture time, stress levels, matrix crack spacing, fiber volume fraction and oxidation temperature on the peak strain and the Interface Slip lengths have been investigated. The experimental fatigue hysteresis loops, Interface Slip lengths, peak strain and Interface oxidation length of cross-ply SiC/MAS (magnesium alumino-silicate, MAS) composite under cyclic fatigue and stress rupture at 566 and 1093 °C in air have been predicted.
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Synergistic effect of Interface wear and loading sequence on Interface debonding and relative Slipping of fiber-reinforced ceramic-matrix composites
Theoretical and Applied Fracture Mechanics, 2016Co-Authors: Longbiao LiAbstract:Abstract This study investigates the synergistic effect of Interface wear and loading sequence on Interface debonding and relative Slipping of fiber-reinforced ceramic-matrix composites (CMCs). There are five different fatigue loading sequences considered in the present analysis. Based on the fatigue damage mechanism of fiber Slipping relative to the matrix upon unloading/reloading, the Interface debonded length and Interface Slip lengths are determined using the fracture mechanics approach. The relationships between Interface debonding, Interface Slipping, Interface wear, cycle number, peak stress and loading sequence have been determined. The fatigue hysteresis loops of C/SiC composite under three-stage cyclic fatigue loading have been predicted using the present analysis.
Li Longbiao - One of the best experts on this subject based on the ideXlab platform.
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Modeling cyclic fatigue hysteresis loops of 2D woven ceramic-matrix composite at elevated temperatures in air considering multiple matrix cracking modes
Theoretical and Applied Fracture Mechanics, 2016Co-Authors: Li LongbiaoAbstract:Abstract In this paper, the cyclic fatigue hysteresis loops of 2D woven SiC/SiC ceramic-matrix composites (CMCs) at elevated temperatures has been investigated. The Interface Slip between fibers and the matrix existed in the matrix cracking mode 3 and mode 5, in which matrix cracking and Interface debonding occurred in the longitudinal yarns, are considered as the major reason for hysteresis loops of 2D woven CMCs. The hysteresis loops of 2D SiC/SiC composite corresponding to different peak stresses, test conditions and loading frequencies have been predicted using present analysis. The damage parameter, i.e., the proportion of matrix cracking mode 3 in the entire matrix cracking modes of the composite, and the hysteresis dissipated energy increase with increasing fatigue peak stress. With increasing cycle number, the Interface shear stress in the longitudinal yarns decreases, leading to transition of Interface Slip types of matrix cracking mode 3 and mode 5.
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Modeling for cyclic loading/unloading hysteresis loops of carbon fiber-reinforced ceramic-matrix composites at room and elevated temperatures. Part I: Theoretical analysis
Engineering Fracture Mechanics, 2016Co-Authors: Li LongbiaoAbstract:Abstract The hysteresis loops models of fiber-reinforced ceramic-matrix composites (CMCs) are developed based on the Coulomb friction law instead of a constant frictional shear stress usually assumed in hysteresis analysis. Based on damage mechanism of fiber Slipping relative to matrix upon loading/unloading, the Interface Slip lengths are obtained by fracture mechanics approach. The effects of matrix stochastic cracking, fiber volume fraction, Interface debonded energy, Interface frictional coefficient and fiber Poisson ratio on hysteresis loops, Interface Slip lengths and Interface Slip stresses have been analyzed.
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Modeling the Effect of Multiple Matrix Cracking Modes on Cyclic Hysteresis Loops of 2D Woven Ceramic-Matrix Composites
Applied Composite Materials, 2016Co-Authors: Li LongbiaoAbstract:In this paper, the effect of multiple matrix cracking modes on cyclic loading/unloading hysteresis loops of 2D woven ceramic-matrix composites (CMCs) has been investigated. The Interface Slip between fibers and the matrix existed in matrix cracking mode 3 and mode 5, in which matrix cracking and Interface debonding occurred in longitudinal yarns, are considered as the major reason for hysteresis loops of 2D woven CMCs. The effects of fiber volume content, peak stress, matrix crack spacing, Interface properties, matrix cracking mode proportion and Interface wear on Interface Slip and hysteresis loops have been analyzed. The cyclic loading/unloading hysteresis loops of 2D woven SiC/SiC composite corresponding to different peak stresses have been predicted using the present analysis. It was found that the damage parameter, i.e., the proportion of matrix cracking mode 3 in the entire cracking modes of the composite, increases with increasing peak stress.
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Modeling the effect of oxidation on hysteresis loops of carbon fiber-reinforced ceramic-matrix composites under static fatigue at elevated temperature
Journal of The European Ceramic Society, 2016Co-Authors: Li LongbiaoAbstract:Abstract An analytical method has been developed to investigate the effect of oxidation on the hysteresis loops of fiber-reinforced ceramic-matrix composites (CMCs) under static fatigue at elevated temperature. The oxidation region propagating model has been adopted to analyze the oxidation effect on the hysteresis loops, which is controlled by Interface frictional Slip and diffusion of oxygen gas through matrix multicrackings. Based on the damage mechanism of fiber Slipping relative to matrix, the hysteresis loops models corresponding to different Interface Slip cases considering Interface oxidation have been established. The relationships between hysteresis loops, hysteresis dissipated energy, Interface Slip and oxidation time have been established. The effects of stress level, matrix crack spacing, fiber volume content and oxidation temperature on the hysteresis dissipated energy, Interface debonding, oxidation and Slip lengths versus oxidation time have been analyzed. The experimental hysteresis loops of C/[Si–B–C] composite under static fatigue in air at 1200 °C have been predicted.
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Cyclic loading/unloading hysteresis behavior of fiber-reinforced ceramic–matrix composites at room and elevated temperatures
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2015Co-Authors: Li LongbiaoAbstract:Abstract In this paper, the cyclic loading/unloading hysteresis behavior of unidirectional C/SiC composite at room and elevated temperatures has been investigated. An approach to predict the hysteresis loops has been developed using the Coulomb friction law to describe the fiber/matrix Interface shear stress. The Interface debonded length, unloading Interface counter-Slip length and reloading Interface new-Slip length were determined by fracture mechanics approach. Based on the Slipping range between fibers and matrix in the Interface debonded region, the hysteresis loops have been divided into four different cases. The relationship between the hysteresis loops, hysteresis loss energy, Interface debonding and Interface Slipping has been established. The hysteresis loops of unidirectional C/SiC composite have been predicted corresponding to different peak stresses at room and elevated temperatures. With the increase of peak stress, the hysteresis loops at room temperature change from the Interface Slip Case 2, i.e., the Interface partially debonding and fiber partially Slipping relative to matrix, to the Interface Slip Case 3, i.e., the Interface completely debonding and fiber partially Slipping relative to matrix; however, at an elevated temperature of 800 °C in air atmosphere, the hysteresis loops change from the Interface Slip Case 2 to Case 4, i.e., the Interface completely debonding and fiber completely Slipping relative to matrix in the Interface debonded region, due to interphase oxidation.
Li-zhong Jiang - One of the best experts on this subject based on the ideXlab platform.
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Analysis on natural vibration characteristics of steel-concrete composite truss beam
Steel and Composite Structures, 2020Co-Authors: Li-zhong Jiang, Wangbao Zhou, Yulin Feng, Binbin HeAbstract:In order to study the natural vibration characteristics of steel-concrete composite truss beam (SCCTB), the influence of multiple factors such as Interface Slip, shear deformation and moment of inertia are considered. Afterwards, based on the Hamilton principle the vibration control differential equation and natural boundary conditions of SCCTB are deduced. By solving SCCTB differential equations of vibration control, an analytical calculation method is proposed for analyzing the natural vibration characteristics of SCCTB. The natural frequencies of SCCTBs with different degrees of shear connection and effective lengths are calculated by using the analytical method, and the results are compared against those obtained from ANSYS finite element numerical calculation method. The results show that the analytical method considering the influence factors such as Interface Slip, shear deformation and moment of inertia are in good agreement with those obtained from ANSYS finite element numerical calculation method. This evidences the correctness of the analytical method and show that the method proposed exhibits improvement over the previously developed theories for the natural vibration characteristics of SCCTB. Finally, based on the analytical method, the influence factors of SCCTB natural vibration characteristics are analyzed. The results indicate that the influence of Interface Slip stiffness on SCCTB\'s natural frequency is more than 10% and therefore cannot be neglected. Moreover, shear deformation has an effect of more than 35% on SCCTB\'s natural frequency and the effect cannot be ignored either in this case too.
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Improved Finite Beam Element Method to Analyze the Natural Vibration of Steel-Concrete Composite Truss Beam
Shock and Vibration, 2017Co-Authors: Li-zhong Jiang, Wangbao Zhou, Xilin ChaiAbstract:Based on Hamilton’s principle, this study has developed a continuous treatment for the steel-concrete composite truss beam (SCCTB). It has also deduced the SCCTB element stiffness matrix and mass matrix, which include the effects of Interface Slip, shear deformation, moment of inertia, and many other influencing factors. A finite beam element method (FBEM) program for SCCTB’s natural vibration frequency has been developed and used to calculate the natural vibration frequencies of several SCCTBs with different spans and different degrees of shear connections. The FBEM’s calculation results of several SCCTBs agree well with the results obtained from ANSYS. Based on the results of this study, the following conclusions can be drawn. For the SCCTB with high-order natural vibration frequency and with short span, the effect of the shear deformation is greater. Hence, the effect of the shear deformation on the SCCTB’s high-order natural vibration frequency cannot be ignored. On the other hand, the effect of the Interface Slip on the SCCTB’s high-order natural vibration frequency is insignificant. However, the effect of the Interface Slip on the SCCTB’s low-order natural vibration frequency cannot be ignored.
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Effects of Interface Slip and semi-rigid joint on elastic seismic response of steel-concrete composite frames
Journal of Central South University of Technology, 2010Co-Authors: Jing-jing Qi, Li-zhong JiangAbstract:The stiffness matrix of semi-rigidly connected composite beams considering Interface Slip was established and the calculation method for elastic seismic response of composite frame was derived. The corresponding calculation programs were developed. Introducing the dimensionless quantities that were related to the connector shearing stiffness and the joint rotation stiffness, the influences of Interface Slip and semi-rigid joint on composite frame were transferred to quantitative parameter analysis, taking account of cross sectional properties, materials and linear stiffness of composite beam synthetically. Based on the calculation programs, free vibration frequencies and seismic responses of semi-rigid joint steel-concrete composite frame considering Interface Slip were calculated. The influences of Interface Slip and semi rigid joint on dynamic characteristics and seismic response were analyzed and the seismic design advices were presented. The results show that the Interface Slip decreases the free vibration frequencies and increase the seismic responses of composite frame. The semi-rigid joint reduces the free vibration frequencies and increases seismic responses of composite frame compared with rigid joint. With the increase of joint rotational stiffness, the elastic seismic responses of composite frame increase firstly and then decrease. The effects are related to the ratio of joint rotation stiffness to linear stiffness of composite beam.
Pc Structure - One of the best experts on this subject based on the ideXlab platform.
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Experimental Study on the Interface Slip of New Type of Steel-encased Concrete Composite Beams
Journal of Sichuan University, 2020Co-Authors: Zhang Rong-guo, Pc StructureAbstract:To study the Interface Slip and the deflection properties of a new type of steel-encased concrete composite beams,four full size simply supported specimens with different shear connection coefficient were designed.One was a beam with full shear connection,and the others with partial shear connection.According to the experiment,a set of load-Slip curves and load-deflection curves are derived.Based on these results,the Interface Slip development process and distribution laws are gained.Taking the Interface Slip into account,a nonlinear finite element analysis model is established by using the finite element analysis soft-ANSYS,and gains a reasonable shearing connection coefficient.Based on the actual code,a theoretical formula is proposed for deflection.The results of finite element model and theoretical formula are proved to be in good agreement with the experimental data.
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Research on the Interface Slip of New Type Steel-encased Concrete Composite Beams with Partial Shear Connection
Natural Science Journal of Xiangtan University, 2020Co-Authors: Zhang Rong-guo, Li Aiqun, Pc StructureAbstract:In view of at some problems of common steel-concrete beams,a new type of steel-encased concrete composite beams is put forward.To study the Interface Slip and deformation character,four simple supported specimens of full size have been performed,the load-Slip curves,load-deflection curves are established through the experiment.Based on these results,the Interface Slip development process and laws are gained.Considering the Interface Slip,a nonlinear finite element analysis model is established by using finite element analysis soft-ANSYS,and gained a reasonable shearing connection coefficient.Based on actual code,a theoretical formula is proposed for deflection.The results of finite element model and theoretical formula are proved to be in good agreement with the experimental results.
Wang Lian - One of the best experts on this subject based on the ideXlab platform.
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Analysis of Interface Slip and Lift Displacement on Composite Beams of Steel Truss and Concrete by Finite Element Method
Journal of Northeastern University, 2020Co-Authors: Wang LianAbstract:Spatial analysis system for the composite beams of steel truss and concrete is presented. The long main span of the cable stayed Wuhu bridge with composite beams of steel truss and concrete on Yangtse River was analyzed using the system by finite element method. The distribution graphs of the Interface Slip and lift displacement along the longitudinal directions of the beam are obtained. The function of the Interface Slip and lift displacement and the shear mechanism of the connector are shown on the composite beams.The system can provide a scientific basis for the engineering design with composite beams of steel truss and concrete.
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Nonlinear Full-range Analysis on Steel Enclosed Concrete Beams
Journal of Shenyang Architectural and Civil Engineering Institute, 2020Co-Authors: Wang LianAbstract:On the basis of finite element method,nonlinear full range analytical model of the steel encased concrete beams is presented,the calculating programme is drawn up,the normal process of bearing capacity,deformation and Interface Slip,stress distribution for steel encased concrete beams are obtained,with provide theoretical basis for the engineering design with such beams.