Tensile progressive damage and compressive postbuckling analysis of open-hole laminate composites

2020 ◽  
Vol 39 (17-18) ◽  
pp. 637-653
Author(s):  
Huairong Kang ◽  
Pengfei He ◽  
Cunman Zhang ◽  
Ying Dai ◽  
Zhongde Shan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Damage Mechanics ◽  
Failure Process ◽  
Tensile Failure ◽  
Progressive Damage ◽  
Laminate Composites ◽  
Crack Distribution ◽  
Failure Patterns ◽  
Fiber Damage ◽  
Open Hole

Laminate composites contain holes as a means of connection in industrial applications. A better understanding of the mechanical properties of open-hole components is necessary. Herein, progressive damage postbuckling analysis models are proposed for investigation of tensile damage and compressive buckling behaviors of open-hole laminate composites. The progressive damage model is based on failure criteria provided by the continuum damage mechanics model; virtual crack closure technology was employed to calculate the energy release rate for crack delamination in compressive postbuckling analysis. The models were utilized to analyze variations in the tensile and compressive mechanical properties, failure process, and buckling evolution of open-hole laminate composites using finite element analysis. The tensile failure patterns and failure processes of plies with different open-hole laminate composite angles were obtained and analyzed. Buckling characteristics, as well as the progression of buckling onset, buckling propagation, crack delamination, unstable delamination, and global buckling, were investigated. The influence of delamination crack length and crack distribution on the buckling properties of open-hole laminate composites are discussed in detail. Additionally, unstable and stable buckling characteristics were examined. The numerical results were in good agreement with theoretical and experimental results; damage initiated at the edge of a hole propagated to two sides with the onset of matrix damage, followed by fiber damage. The fiber damage of a 0°-ply led ultimately to laminate failure. The laminate with a symmetrical crack distribution showed stable buckling, whereas a short, nonsymmetrical distribution of cracks usually led to unstable buckling and delamination.

Fatigue-Cumulative Damage Model of RC Crane Girders Strengthened with FRP Strips

2008 ◽  
Vol 385-387 ◽  
pp. 165-168
Author(s):  
Shan Suo Zheng ◽  
Bin Wang ◽  
Lei Li ◽  
Liang Zhang ◽  
Pi Ji Hou
Keyword(s):  
Damage Mechanics ◽  
Flexural Rigidity ◽  
Failure Process ◽  
Damage Model ◽  
Cumulative Damage ◽  
Good Time ◽  
Failure Patterns ◽  
Damage And Fracture ◽  
Cumulative Damage Model ◽  
Frp Strips

The cumulative damage of the reinforced concrete (RC) crane girders occurred by overload, fatigue and other reasons in service may deteriorate the safety of RC crane girders seriously, so it is necessary to analyze the damage mechanism and rationally reinforce them in good time. In this paper, RC crane girder strengthened with CFRP strips is taken as a target, and the mechanical performance degradation under fatigue load is studied. According to the basic theory of continuum damage mechanics, a damage variable is defined by flexural rigidity, and fatigue- cumulative damage model, which describes the process of damage and fracture, is established. The variation law of cumulative damage of RC crane girders strengthened with FRP strips under crane load is discussed, and the failure patterns such as concrete cracking, debonding between CFRP strips and concrete, yield of steel bars etc., are studied. The criterion which can be used to estimate the cumulative damage degree of strengthened RC crane girders is proposed. Finally, the evolution of the fatigue damage in the RC crane girders strengthened with CFRP strips is numerically simulated, and the results show that the proposed model can correctly describe the damage and failure process of strengthened RC crane girders. The research will provide a reference for the damage analysis and reinforcement of RC crane girders strengthened with CFRP strips.

Material orthotropy effects on progressive damage analysis of open-hole composite laminates under tension

2017 ◽  
Vol 36 (20) ◽  
pp. 1473-1486 ◽  
Author(s):  
Song Zhou ◽  
Yi Sun ◽  
Boyang Chen ◽  
Tong-Earn Tay
Keyword(s):  
Composite Laminates ◽  
Damage Mechanics ◽  
Damage Model ◽  
Continuum Damage Mechanics ◽  
Tensile Loading ◽  
Progressive Damage ◽  
Cohesive Elements ◽  
Damage Initiation ◽  
Proposed Model ◽  
Open Hole

The sizes effects on the strengths of open-hole fibre-reinforced composite laminates subjected to tensile loading (OHT) have been investigated widely. However, little attention has been paid to the influence of material orthotropy. This paper presents a progressive damage model for the model failure of notched laminates under tensile loading based on continuum damage mechanics and cohesive elements. The effects of orthotropy on the failure of notched laminates with seven different ply sequences are investigated by our proposed model. The prediction results adopting the Hoffman and Pinho failure criterions to determine matrix damage initiation are compared with the results of experiments. Our proposed models are able to predict the strong influence of orthotropy on strengths of open-hole laminate under tension, and model using Pinho criterion can predict the open-hole tension strength most accurately.

Static strength prediction in laminated composites by using discrete damage modeling

2016 ◽  
Vol 51 (10) ◽  
pp. 1473-1492 ◽  
Author(s):  
Kevin Hoos ◽  
Endel V Iarve ◽  
Michael Braginsky ◽  
Eric Zhou ◽  
David H Mollenhauer
Keyword(s):  
Compressive Strength ◽  
Input Data ◽  
Damage Mechanics ◽  
Laminated Composites ◽  
Matrix Cracking ◽  
Damage Modeling ◽  
Fiber Failure ◽  
Failure Patterns ◽  
Open Hole ◽  
Discrete Damage Modeling

Discrete Damage Modeling of complex local failure patterns in laminated composites including matrix cracking, delamination, and fiber failure was performed. Discrete Damage Modeling uses the Regularized eXtended Finite Element Method for the simulation of matrix cracking at initially unknown locations and directions independent of the mesh orientation. Cohesive interface model is used both for Mesh Independent Cracking as well as delamination propagation. The fiber failure mode is modeled by two different methods in tension and compression. Tensile failure is predicted by Critical Failure Volume criterion, which takes into account volumetric scaling of tensile strength. Compression fiber failure is simulated with a single parameter continuum damage mechanics model with non-compressibility condition in the failed region. Ply level characterization input data were used for prediction of notched and unnotched laminate strength. All input data required for model application is directly measured by ASTM tests except tensile fiber scaling parameter and compression fiber failure fracture toughness, which were taken from literature sources. The model contains no internal calibration parameters. Tensile and compressive strength of unnotched and open hole composite laminates IM7/977-3 has been predicted and compared with experimental data. Three different layups, [0/45/90/−45]2S, [30/60/90/−60/−30]2S, and the [60/0/−60]3S, were modeled and tested and showed good agreement with experiment in the case of tensile loading, whereas the compressive strength was generally under predicted for unnotched laminates and overpredicted for open hole laminates.

scholarly journals Numerical tests on thermal cracking characteristics of rocks with different scales

2018 ◽  
Vol 10 (8) ◽  
pp. 168781401879214 ◽  
Author(s):  
Yang Xiao ◽  
Rui Zhao ◽  
Qing-Xiang Huang ◽  
Jun Deng ◽  
Jun-Hui Lu
Keyword(s):  
Acoustic Emission ◽  
Thermal Destruction ◽  
Thermal Damage ◽  
Process Analysis ◽  
Failure Process ◽  
Acoustic Emissions ◽  
Thermal Cracking ◽  
Tensile Failure ◽  
Failure Patterns ◽  
Different Diameters

Realistic failure process analysis, a thermal software simulation, was used to explore the scale effect of thermal cracking of rock under the thermal–mechanical coupling loading. The patterns and characteristics of thermal destruction were analyzed by simulating the thermal cracking of rocks with the same diameter different lengths, the same length but different diameters, and the same size ratio but different sizes (same length/diameter ratio but with different diameters). The acoustic emission and energy changes were also studied during thermal destruction. The results represented that the main forms of thermal cracking are tensile failure and shear failure. The smaller the scale is (length, diameter, and size), the more complex the pattern of thermal damage exhibited as failure patterns of inverted “S” or “V.” With the increasing scale, thermal damage models were simpler. The elastic modulus was determined by the diameter of specimens, and the peak stress was determined by the length of specimens. Overall, as the scale increased, the stress intensity decreased, but the number of acoustic emissions and acoustic emission energy and the corresponding accumulation increased.

Application of GTN Model in Tensile Fracture of Pipeline Steel

2018 ◽  
Vol 777 ◽  
pp. 451-456
Author(s):  
Ye Da Lian ◽  
Ren Qiang Wu ◽  
Bing Zhang ◽  
Tao Feng
Keyword(s):  
Damage Mechanics ◽  
Volume Fraction ◽  
Plastic Material ◽  
Pipeline Steel ◽  
Failure Process ◽  
Tensile Failure ◽  
Tensile Fracture ◽  
X70 Pipeline Steel ◽  
Finite Element Software ◽  
Mechanics Model

In this paper, the macroscopic mechanical behavior of tensile fracture of X70 pipeline steel is combined with the evolution of mesoscopic pores. The ABAQUS finite element software was used to analyze the variation of pore volume fraction in the tensile failure process of unilateral notched specimens with Gurson-Tvergaard-Needleman (GTN) mesoscopic damage model. Combined with the unilateral notched tensile test and the numerical simulation results, the damage mechanics model of pipeline steel based on void volume fraction is established. The results show that the volume fraction of pores is a mesomechanical parameter based on the damage of the micro-holes in the metallic plastic material, which is a bridge between the mesoscopic damage characteristics and the macro-mechanical parameters. Establishing the damage mechanics model of high strength pipeline steel with hole volume fraction as damage variable can truly reflect the macro-meso-mechanics behavior of X70 pipeline steel during unilateral notching.

scholarly journals Experimental Study and Numerical Simulation on Failure Process of Reinforced Concrete Box Culvert

2020 ◽  
Vol 2020 ◽  
pp. 1-13
Author(s):  
Yafeng Gong ◽  
Yulin Ma ◽  
Guojin Tan ◽  
Haipeng Bi ◽  
Yunze Pang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Finite Element ◽  
Reinforced Concrete ◽  
Failure Process ◽  
Side Wall ◽  
Load Test ◽  
Tensile Failure ◽  
Scale Model ◽  
Road Transportation ◽  
Contact Behaviour

Culvert is an important part of roads whose healthy operation is related to the efficiency and safety of road transportation. Therefore, it is very important to evaluate the safety of culvert structure by load test. Four types of prefabricated reinforced concrete box culverts (integral BC, round hinged BC, flat seam BC, and mortise BC) were designed in this paper. By designing a scale model test, the sensor system was used to test the mechanical properties of BC, which included dial indicators, strain gauges, and a pressure sensor. The finite element analysis based on material nonlinearity and contact nonlinearity of round hinged BC and integral BC was carried out. After validating the finite element models, mechanical properties of reinforcement and concrete of BCs were analyzed. The experimental results show that the failure mode of BC was tensile failure of concrete at the bottom of top slab under bending action, and integral BC had the maximum carrying capacity. The contact behaviour of sliding and rotating at hinge joints caused the first principal tensile stress of concrete at the internal surface of the side wall below hinge joints.

Progressive Failure Monitoring of Fiber-Reinforced Metal Laminate Composites Using a Nondestructive Approach

2019 ◽  
Vol 2 (2) ◽  
Author(s):  
Rami Carmi ◽  
Brian Wisner ◽  
Prashanth A. Vanniamparambil ◽  
Jefferson Cuadra ◽  
Arie Bussiba ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Failure Modes ◽  
Progressive Failure ◽  
Failure Process ◽  
Digital Signal ◽  
Dynamic Mechanical Properties ◽  
Fiber Reinforced ◽  
Laminate Composites ◽  
Material State ◽  
Failure Monitoring

Fiber-reinforced metal laminate (FRML) composites are currently used as a structural material in the aerospace industry. A common FRML, glass layered aluminum reinforced epoxy (Glare), possesses a set of mechanical properties which was achieved by designing its layup structure to combine metal alloy and fiber-reinforced polymer phases. Beyond static and dynamic mechanical properties at the material characterization phase, however, the need exists to develop methods that could assess the evolving material state of Glare, especially in a progressive failure context. This paper presents a nondestructive approach to monitor the damage at the material scale and combine such information with characterization and postmortem evaluation methods, as well as data postprocessing to provide an assessment of the failure process during monotonic loading conditions. The approach is based on multiscale sensing using the acoustic emission (AE) method, which was augmented in this paper in two ways. First, by applying it to all material components separately in addition to actual Glare specimens. Second, by performing testing and evaluation at both the laboratory scale as well as at the scale defined inside the scanning electron microscopy. Such elaborate testing and nondestructive evaluation results provided the basis for the application of digital signal processing and machine learning methods which were capable to identify data trends that are shown to be correlated with the evolution of failure modes in Glare.

Progressive Damage Analysis of Random Chopped Fiber Composite Using Finite Elements

2010 ◽  
Vol 133 (1) ◽  
Author(s):  
Yi Pan ◽  
Assimina A. Pelegri
Keyword(s):  
Mechanical Properties ◽  
Cohesive Zone Model ◽  
Fiber Composite ◽  
Damage Model ◽  
Interfacial Debonding ◽  
Matrix Cracking ◽  
Uniaxial Tensile ◽  
Zone Model ◽  
Progressive Damage ◽  
Fiber Damage

The mechanical properties of random chopped fiber composites are analyzed using micromechanical principles. A progressive damage model is adopted to investigate the damage and failure of the material. A representative volume element is generated numerically based on microscopic observations that capture the complex mesostructure of the random chopped fiber composite specimens. Sequentially, the mechanical properties are obtained using a micromechanics approach, particularly, the homogenization method. The underlying hypothesis insinuates that damage mechanisms such as matrix cracking, fiber damage, and interfacial debonding are responsible for the damaged behavior of the composite. Matrix cracking and fiber damage are modeled by progressive degradation of their respective stiffnesses. The interfacial debonding is modeled with a cohesive zone model. The prediction of uniaxial tensile response is compared with experimental data.

Three Dimensional Numerical Approach to Splitting Failure of Rock Discs

2007 ◽  
Vol 353-358 ◽  
pp. 921-924
Author(s):  
Tao Xu ◽  
Tian Hui Ma ◽  
Chun An Tang ◽  
Zheng Zhao Liang
Keyword(s):  
Standardized Test ◽  
Process Analysis ◽  
Failure Process ◽  
Numerical Approach ◽  
Rock Failure ◽  
Test Method ◽  
Tensile Failure ◽  
Numerical Code ◽  
Failure Patterns ◽  
Splitting Failure

The Brazilian splitting tests have been commonly and widely used as a standardized test method on disc or cylinder specimens to measure the indirect tensile strength of rocks in mining engineering and other rock engineering. In this paper, a novel numerical code, 3D Rock Failure Process Analysis code, was applied to implement the splitting tensile failure tests on rock discs. The influences of the heterogeneity on stress distribution in rock are also discussed and the splitting failure patterns of specimens subjected to Brazilian tests are simulated. The simulated splitting results of rock discs were found quite realistic, which indicate that the rock failure analysis method is applicable and practical for the study of rock disc splitting failure.

Progressive damage simulation of open-hole composite laminates under compression based on different failure criteria

2016 ◽  
Vol 51 (9) ◽  
pp. 1239-1251 ◽  
Author(s):  
Song Zhou ◽  
Yi Sun ◽  
Boyang Chen ◽  
Tong-Earn Tay
Keyword(s):  
Composite Structures ◽  
Damage Mechanics ◽  
Failure Modes ◽  
Failure Criteria ◽  
Strength Prediction ◽  
Progressive Damage ◽  
Cohesive Elements ◽  
Damage Initiation ◽  
Open Hole ◽  
Matrix Damage

The strength prediction of open-hole fibre-reinforced composite laminate under compression is very important in the design of composite structures. The modelling of fibre, matrix damage and delamination plays an important role in the understanding of the damage mechanics of laminate under open-hole compression. In this article, a progressive damage model for open-hole compression that is based on continuum shell elements and cohesive elements is established to model in-plane damage and delamination, respectively. The damage mechanics of sublaminate-scaled laminates with ply sequence [45/0/−45/90]ms and ply-level-scaled laminates with ply sequence [45n/0n/−45n/90n]s are investigated by our proposed model. The Tsai-Wu and Hoffman failure criteria are employed for the determination of matrix damage initiation. Compared with the experiments, the numerical results using the Tsai-Wu criterion exhibit better accuracy regarding open-hole compression strength prediction and failure modes simulation.

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