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progressive damage Analysis(PDA)of Carbon Fiber Plates with Out-of-Plane Fold under Pressure

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Computer Modeling in Engineering & Sciences 2020年第8期124卷 545-559页

作者： Tao Zhang Jinglan Deng Jihui Wang Composite Materials and Engineering Laboratory Wuhan University of TechnologyWuhan430070China

The out-of-plane fold is a common defect of composite materials during the manufacturing process and will greatly affect the compressive strength as well as the service *** it of great importance to investigate the influence of out-of-plane defects to the compressive strength of laminate plates of composite materials,and to understand the patterns of defect ***,the strip method is applied in this article to create out-of-plane defects with different aspect ratios in laminated plates of composite materials,and a compressive performance test is conducted to quantify the influence of out-of-plane *** result shows that the compressive strength becomes weaker with a greater aspect *** the highest aspect ratio is set to 0.12 in the experiment,the compressive strength reduces by 36.1%.Then we establish a 3-D progressive damage model based on continuum mechanics,and write it into the UMAT subroutine together with the 3-D Hashin criteria and the non-linear degradation criteria of materials.3-D solid modeling is performed for the samples with an out-of-plane fold based on ABAQUS,and progressive damage analysis is conducted to acquire the inplane evolution process of initial failure strength with different *** experimental results agree well with the simulation results.

关键词： Composite materials out-of-plane fold compressive strength continuum mechanics progressive damage UMAT

3D progressive damage Based Macro-Mechanical FE Simulation of Machining Unidirectional FRP Composite

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Chinese Journal of Mechanical Engineering 2018年第3期31卷 128-143页

作者： Yan-Li He Joao-Paulo Davim Hong-Qian Xue Key Laboratory of Contemporary Design and Integrated Manufacturing Technology of Ministry of Education School of Mechanical EngineeringNorthwestern Polytechnical University Department of Mechanical Engineering University of AveiroCampus Santiago

Finite element(FE) simulation is a powerful tool for investigating the mechanism of machining fiber?reinforced polymer composite(FRP). However in existing FE machining simulation works,the two?dimensional(2 D) progressive damage models only describe material behavior in plane stress,while the three?dimensional(3 D) damage models always assume an instantaneous sti ness reduction pattern. So the chip formation mechanism of FRP under machin?ing is not fully analyzed in general stress state. A 3 D macro?mechanical based FE simulation model was developed for the machining of unidirectional glass fiber reinforced plastic. An energy based 3 D progressive damage model was proposed for damage evolution and continuous sti ness degradation. The damage model was implemented for the Hashin?type criterion and Maximum stress criterion. The influences of the failure criterion and fracture energy dissipa?tion on the simulation results were studied. The simulated chip shapes,cutting forces and sub?surface damages were verified by those obtained in the reference experiment. The simulation results also show consistency with previous 2 D FE models in the reference. The proposed research provides a model for simulating FRP material behavior and the machining process in 3 D stress state.

关键词： FRP Macro mechanical Machining Finite element progressive damage

Quantitative characterization of damage-aggravation effect caused by progressive damage

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Acta Mechanica Sinica 2021年第2期37卷 349-365页

作者： Qindong Lin Shihai Li Chun Feng Dong Zhou Key Laboratory for Mechanics in Fluid Solid Coupling Systems Institute of MechanicsChinese Academy of SciencesBeijing 100190China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China

Aiming at the progressive damage phenomenon in geotechnical field,it attempts to study the effect of progressive damage on the macro-bearing ***,based on the theoretical analysis of a two-dimensional plane inside representative volume element,it is proposed that progressive damage will occur if the bearing capacity of microplanes is ***,“damage-aggravation effect”is proposed according to the difference between the macro-bearing capacity of entire plane and the sum of bearing capacity of all microplanes when progressive damage ***,progressive damage ratio K_(t)is proposed to quantify“damage-aggravation effect”.Finally,based on the rod model,the correspondence between K_(t),and some influence factors is studied by theoretical analysis and numerical *** results show that“damage-aggravation effect”does exist,and the macro-bearing capacity of entire plane is less than the sum of bearing capacity of all microplanes when progressive damage *** the bearing capacity of rods in the rod model obeys uniform distribution,as the minimum of bearing capacity increases linearly,the macro-bearing capacity increases linearly,and K_(t)decreases inversely.

关键词： progressive damage Bearing strength damage-aggravation effect progressive damage ratio

Effect of stress paths on failure mechanism and progressive damage of hard-brittle rock

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Journal of Mountain Science 2021年第9期18卷 2486-2502页

作者： CHEN Zi-quan HE Chuan HU Xiong-yu MA Chun-chi Key Laboratory of Transportation Tunnel Engineering Ministry of EducationSouthwest Jiaotong UniversityChengdu 610031China Key Laboratory of Engineering Structures of Heavy Haul Railway Ministry of EducationCentral South UniversityChangsha 410075China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China

During deep buried hard-brittle rock tunnel excavation,the surrounding rock experiences a complicated stress path and stress adjustment *** the adjusted stress exceeds the ultimate bearing capacity of rockmass,a rock failure mode defined as stress-cracking type will *** order to investigate the effect of stress paths on failure mechanism and progressive damage of deep-buried rockmass,the cyclic loading-unloading,loading-unloading,uniaxial,conventional and unloading triaxial compression tests on samples of hard-brittle sandstone were *** to the experimental results,increase in the confining pressure was beneficial to improve the mechanical parameters of rock,but it will reduce the brittle failure *** with conventional triaxial compression,the sandstone under unloading state had more remarkable stress drop and unstable failure ***,it was found that the energy dissipation and energy release in the whole process of rock deformation were the internal power of driven rock progressive *** the increase of confining pressure,the energy hardening and energy accumulation features of rock were weakened,while the progressive damage evolution characteristics could be *** unloading state,more energy could be converted into elastic energy in the energy softening phase(σeb-σP),so that the prepeak damage rate of rock was lower than that of conventional triaxial compression ***,the energy dissipation rate of rock after peak strength decreased linearly with the increase of confining pressure under conventional triaxial compression state,while in unloading state it showed the opposite law.

关键词： Hard-brittle rock Stress path Confining pressure Failure mechanism progressive damage

Nonlinear progressive damage model for composite laminates used for low-velocity impact

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Applied Mathematics and Mechanics(English Edition) 2013年第9期34卷 1145-1154页

作者：郭卫薛璞杨军 School of Aeronautics Northwest Polytechnical University Chengdu Aircraft Design and Research Institute

In order to effectively describe the progressively intralaminar and interlam- inar damage for composite laminates, a three dimensional progressive damage model for composite laminates to be used for low-velocity impact is presented. Being applied to three-dimensional （3D） solid elements and cohesive elements, the nonlinear damage model can be used to analyze the dynamic performance of composite structure and its failure be- havior. For the intralaminar damage, as a function of the energy release rate, the damage model in an exponential function can describe progressive development of the damage. For the interlaminar damage, the damage evolution is described by the framework of the continuum mechanics through cohesive elements. Coding the user subroutine VUMAT of the finite element software ABAQUS/Explicit, the model is applied to an example, i.e., carbon fiber reinforced epoxy composite laminates under low-velocity impact. It is shown that the prediction of damage and deformation agrees well with the experimental results.

关键词： composite laminate progressive damage delamination energy release rate low-velocity impact

Effects of Structural Characteristics of a Bionic Dragonfly Wing on Its Low Velocity Impact Resistance

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Journal of Bionic Engineering 2018年第5期15卷 859-871页

作者： Azadeh Arjangpay Abolfazl Darvizeh Mehdi Yarmohammad Tooski Department of Mechanical Engineering University of Guilan P.O. Box 3756 Rasht Iran Department of Mechanical Engineering Islamic Azad University Bandar Anzali Branch Bandar Anzali Iran Department of Mechanical Engineering lslamic Azad University South Tehran Branch Tehran Iran

The influence of the structural features of dragonfly wings, including the sandwich-type configuration of longitudinal veins and the longitudinal corrugations, on the impact response of a bio-inspired structure is investigated. According to experimental observations of the wing morphology, a novel foam-based composite structure is introduced consisting of E-glass/epoxy face-sheets bonded to a polyurethane foam core. A finite element model is employed to simulate the structural responses of the biomimetic structure under low velocity impact. The initiation and evolution of the impact-induced damage in composite skins are simulated by applying a user-defined progressive damage model together with the interracial cohesive law for intra- and inter-laminar damages, respectively. To simulate the nonlinear behavior of the foam core, a crushable plasticity model is implemented. The numerically obtained results are found to correlate with the experimentally measured ones, acquired by drop-weight testing on a bio-inspired structure. It is numerically predicted that reinforcing the structure with the veins gives the more impact load-bearing capacity and the longitudinal corrugation can increase the stiffness and damage resistance of the structure. Effects of the change in impact location, the configuration of the veins and the corrugated angle on damage resistance of the structures are fully discussed.

关键词： dragonfly wing bio-inspired structure impact response progressive damage Vectorized User-defined Material subroutine

Shear behaviour of anchored jointed rock mass under different engineering conditions considering damage and joint surface morphology

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Underground Space 2023年第6期13卷 316-334页

作者： Zenghui Zhao Wei Sun Shaojie Chen Hao Liu College of Energy and Mining Engineering Shandong University of Science and TechnologyQingdao 266590China State Key Laboratory of Strata Intelligent Control and Green Mining Co-founded by Shandong Province and the Ministry of Science and Technology Shandong University of Science and TechnologyQingdao 266590China Department of Petroleum Engineering China University of Petroleum-BeijingBeijing 102249China

According to different geological conditions and engineering disturbance,three dimensional numerical models of anchored jointed rock mass with two kinds of boundary conditions of constant normal load(CNL)and constant normal stiffness(CNS)were constructed considering the ductility damage of rockbolt,the stiffness degradation of grouting layer and the joint surface *** effects of anchorage angle,joint surface morphology,and boundary conditions on the shear performance of anchorage system were analyzed,and the failure characteristics under different working conditions were ***,the analytical solution of shear strength of anchored system was *** show that the larger the anchorage angle is,the more serious the necking phenomenon of rockbolt will *** damage degree of the bonding layer and the horizontal displacement of the bedding rock mass decrease with the increase of the joint surface *** CNL condition is to instantaneously apply high normal stress,and the CNS condition is to gradually form a high normal stress environment through the superposition of increment on the basis of the initial value,which can resist greater transverse *** is equivalent to enhancing the ductility of the *** shear strength of the system increases with the increase of normal stress and normal *** the normal stiffness will underestimate the shear strength.

关键词： Anchored jointed rock mass Normal stress Normal stiffness progressive damage

Multiscale modeling of mechanical behavior and failure mechanism of 3D angle-interlock woven aluminum composites subjected to warp/weft directional tension loading

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Chinese Journal of Aeronautics 2021年第8期34卷 202-217页

作者： Zhenjun WANG Siyuan YANG Shiping SUN Yingfeng ZHANG Changchun CAI Bowen XIONG Wei YANG Zhifeng XU Huan YU School of Aeronautical Manufacturing Engineering Nanchang Hangkong UniversityNanchang 330063China Hunan Aviation Powerplant Research Institute Aero Engine Corporation of ChinaZhuzhou 412002China School of Mechanical Engineering Northwestern Polytechnical UniversityXi'an 710072China

The mechanical behavior and progressive damage mechanism of novel aluminum matrix composites reinforced with 3D angle-interlock woven carbon fibers were investigated using a multiscale modeling *** mechanical properties and failure of yarns were evaluated using a microscale model under different loading *** this basis,a mesoscale model was developed to analyze the tensile behavior and failure mechanism of the *** interfacial decohesion,matrix damage,and failure of fibers and yarns were incorporated into the microscopic and mesoscopic *** stress–strain curves and fracture modes from simulation show good agreement with the experimental curves and fracture *** interface and matrix damage initiate first under warp directional ***,interfacial failure,weft yarn cracking,and matrix failure occur *** fracture of warp yarn,which displays a quasi-ductile fracture characteristic,dominates the ultimate composites *** weft directional tension,interfacial failure and warp yarn rupture occur at the early and middle *** failure and weft yarn fracture emerge simultaneously at the final stage,leading to the cata-strophic failure of *** weft directional strength and fracture strain are lower than the warp directional ones because of the lower weft density and the more serious brittle fracture of weft yarns.

关键词： Aluminum matrix composites Failure mechanism Mechanical behavior progressive damage Multiscale modeling

Effects of Stacking Sequence and Impactor Diameter on Impact damage of Glass Fiber Reinforced Aluminum Alloy Laminate

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Computers, Materials & Continua 2016年第5期52卷 105-121页

作者： Zhengong Zhou Shuang Tian Jiawei Zhang Center for Composite Materials Harbin Institute of TechnologyHarbinChina Beijing Institute of Mechanical Equipment BeijingP.R.China

The methods of numerical simulation and test are combined to analyze the impact behavior of glass fiber reinforced aluminum alloy laminate(GLARE).A new failure criteria is proposed to obtain the impact failure of GLARE,and combined with material progressive damage method by writing code of *** velocity impact test of GLARE is employed to validate the feasibility of the finite element model *** simulation results have been shown that progressive damage finite element model established is *** the application of the finite element model established,the delamination of GLARE evolution progress is simulated,various failure modes of GLARE during impact are obtained,and the effects of stacking sequence and impactor diameter on the impact damage of GLARE are obtained.

关键词： GLARE Impact behavior progressive damage Finite element method Impact test