A Damage Model for Prediction of the Open-Hole Strength of Glare Laminates

2013 ◽  
Vol 325-326 ◽  
pp. 123-127
Author(s):  
Zi Zhen Cao ◽  
Ji Feng Zhang ◽  
Yun Wan ◽  
Yong Gang Xie
Keyword(s):  
Failure Modes ◽  
Damage Model ◽  
Three Dimensional ◽  
Matrix Cracking ◽  
Failure Behavior ◽  
Cohesive Elements ◽  
Fiber Failure ◽  
Solution Approach ◽  
Present Solution ◽  
Open Hole

A three-dimensional progressive damage model is proposed to predict the open-hole tensile strength of Glare laminates. For the glass fiber reinforced epoxy the user subroutine UMAT is employed for description of the failure modes, such as matrix cracking and fiber failure. Behavior of the delamination between plies of the laminate is described using cohesive elements. Laminates with a rhombic hole, a square hole and a circular hole are taken into consideration separately. The results obtained by the present solution approach are validated with those available in the literatures.

A new progressive damage model for predicting the tensile behavior of the three-dimensional woven carbon/carbon composites using micromechanics method

2021 ◽  
pp. 105678952110354
Author(s):  
Kunlong Wei ◽  
Hongbin Shi ◽  
Jiang Li ◽  
Min Tang
Keyword(s):  
Evolution Equations ◽  
Damage Model ◽  
Three Dimensional ◽  
Failure Behavior ◽  
Progressive Damage ◽  
Cohesive Elements ◽  
Damage Initiation ◽  
Void Defects ◽  
Fiber Matrix ◽  
Progressive Damage Model

A new progressive damage model for the three-dimensional (3 D) woven carbon/carbon (C/C) composites is developed at fiber-matrix level using the micromechanics method. A woven architecture based Representative Volume Element (RVE) model composed of yarns, matrix and yarn/matrix interface is constructed, in which the manufacturing void defects are accounted for. The fiber-matrix concentric cylinder model is employed as a repeating unit cell to represent the yarn, and the matrix micro strain field is computed analytically by the micromechanics method. The maximum stain criteria is utilized for fiber longitudinal breakage, and the Von-Mises criterion is applied for the damage initiation of matrix in both intra-yarns and inter-yarns. The damaged fiber and matrix are modeled by the stiffness degradation method combined with exponential damage evolution equations. The zero thickness cohesive elements governed by bilinear traction-separation constitutive are adopted for yarn/matrix interfacial debonding behavior. The micro progressive damage and failure behavior of the 3 D woven C/C composites subjected to tension is implemented through a developed user-defined material subroutine in commercial software ABAQUS. The predicted stress-strain response is in a good agreement with experimental results. In addition, the effect of manufacturing void defects is also examined by the developed model.

Mechanical and failure behavior of three-dimensional six-directional braided composites bolted joint

2017 ◽  
Vol 36 (10) ◽  
pp. 739-753 ◽  
Author(s):  
Yuling Tang ◽  
Zhengong Zhou ◽  
Shidong Pan ◽  
Zhiyong Tan ◽  
Hongwei Wu
Keyword(s):  
Finite Element ◽  
Failure Modes ◽  
Characteristic Curve ◽  
Damage Model ◽  
Three Dimensional ◽  
Reference Value ◽  
Failure Criteria ◽  
Failure Behavior ◽  
Bolted Joint ◽  
Braided Composites

Experiments and finite element simulation were used to investigate the influence of geometric parameters on failure response of a single-lap bolted joint. Single- and double-bolt joints in three-dimensional six-directional braided composites were tested. The failure modes and mechanisms of the joints were evaluated. To accurately predict bearing strength, a three-dimensional composite damage model was used, which included the Yamada–Sun failure criteria based on the characteristic curve method. The finite element method (FEM) was validated by experimental results. The geometric reference value and failure envelope for the single-lap bolted joint were obtained. The results showed that the carrying capacity of the single-lap bolted joint decreased and the failure mode also changed owing to the secondary bending. It can also be obtained that increased the number of bolt rows can effectively reduce the secondary bending of the plates and thus generated less severe net tensile stresses.

scholarly journals An Optimization Tool for Impact Analysis of Composite Structures

2018 ◽  
Author(s):  
DC Pham
Keyword(s):  
Impact Loading ◽  
Composite Structures ◽  
Impact Analysis ◽  
Failure Modes ◽  
Drop Test ◽  
Matrix Cracking ◽  
Computational Time ◽  
Failure Behavior ◽  
Test Analysis ◽  
Plane Failure

Composite materials exhibit complex failure behavior under impact loading especially such as that for composite landing gear structure. Possible failure modes in composites may include matrix cracking, fiber breakage, kinking, fiber-matrix debonding or delamination between composite plies. In order to better understand the damage mechanisms and non-linear response of composite structures under impact, complex geometries, materials, ply orientations and stacking sequence need to be considered. However, general drop test analysis for composite structures usually takes a lot of computational efforts, and it may be even more expensive for failure analysis and optimization when various structural geometries and design configurations are taken into account. This paper proposes a new methodology for evaluation and optimization of failure behavior of composite structures subjected to impact loading, whereby drop test analysis of composite structures is modeled by explicitly dynamics analysis of two-dimensional structures and implicit analysis of three-dimensional solid structures to predict delamination or out-of-plane failure. The above-mentioned modeling strategy helps speed up the optimization process and considerably save computational time and efforts. The proposed methodology together with reliable optimization algorithms and failure theory criteria are integrated and coded into a FE optimization tool by Python script. It is shown that the optimization tool effectively helps engineers and researchers perform optimization of general composite structures and fully take into account of various geometries, materials, loading configurations, composite stack-up and sequences and individual ply's orientation.

Numerical analysis of damage and failure behavior of concrete

2019 ◽  
Vol 29 (4) ◽  
pp. 570-590 ◽  
Author(s):  
Michael Brünig ◽  
Alexander Michalski
Keyword(s):  
Failure Modes ◽  
Damage Model ◽  
Numerical Procedure ◽  
Image Correlation ◽  
Failure Behavior ◽  
Correlation Technique ◽  
Strain Rate Tensor ◽  
Continuum Damage ◽  
Finite Element Program ◽  
Continuum Damage Model

The paper discusses an anisotropic continuum damage model for concrete and its numerical implementation into a finite element program to provide an efficient approach suitable for boundary-value problems analyzing nonlinear concrete behavior. The phenomenological continuum approach is based on kinematic description of damage. Irreversible deformation behavior as well as volume increase of material samples even under compression loading are simulated by a damage strain rate tensor. The elastic constitutive equations are affected by damage strain tensors modeling decrease of elastic material parameters. The numerical procedure is based on the damage predictor–elastic corrector technique and the corresponding consistent tangent modulus is presented. Different experiments have been performed and deformation fields are analyzed by digital image correlation technique. Numerical simulations of the experiments show good agreement of the results and elucidate stress and damage states in the specimens. They allow prediction of failure modes of the tested specimens agreeing well with photographs of fractured cylinders and cubes. They also demonstrate the efficiency and the applicability of the proposed continuum damage model.

Transient Thermal Analysis and Visco-Plastic Damage Model for Life Prediction of Turbine Components

2014 ◽  
Author(s):  
A. Staroselsky ◽  
T. J. Martin ◽  
B. Cassenti
Keyword(s):  
Finite Element ◽  
Life Prediction ◽  
Failure Modes ◽  
Damage Model ◽  
High Stress ◽  
Three Dimensional ◽  
Dissipated Energy ◽  
Linear Deformation ◽  
Three Dimensional Finite Element ◽  
Turbine Airfoils

This paper reports the process and computer methodology for a physics-based prediction of overall deformation and local failure modes in cooled turbine airfoils, blade outer air seals, and other turbomachinery parts operating in severe high temperature and high stress environments. The computational analysis work incorporated time-accurate, coupled aerothermal CFD with non-linear deformation thermal-structural FEM with a slip-based constitutive model, evaluated at real engine characteristic mission times and flight points for part life prediction. The methodology utilizes a fully-coupled elastic-viscoplastic model that was based on crystal morphology, and a semi-empirical lifing model introduced the use of dissipated energy to estimate the remaining part life in terms of cycles to failure. The method was effective for use with three-dimensional finite element models of realistic turbine airfoils using commercial finite element applications. The computationally predicted part life was calibrated and verified against test data for deformation and crack growth.

A three-dimensional progressive damage model for drop-weight impact and compression after impact

2019 ◽  
Vol 54 (4) ◽  
pp. 449-462 ◽  
Author(s):  
Dinh Chi Pham ◽  
Jim Lua ◽  
Haotian Sun ◽  
Dianyun Zhang
Keyword(s):  
Impact Analysis ◽  
Damage Model ◽  
Three Dimensional ◽  
Matrix Cracking ◽  
Progressive Damage ◽  
Continuum Damage ◽  
Drop Weight ◽  
Compression After Impact ◽  
Weight Impact ◽  
Progressive Damage Model

In this paper, an enhanced three-dimensional continuum damage mechanics model is applied to predict the drop-weight impact response and compression after impact failure of a fiber-reinforced polymer composite specimen. The three-dimensional progressive damage model incorporates a three-dimensional maximum stress criterion to predict the intra-ply damage initiation, followed by a fracture-energy-based smeared crack model to capture the post-peak softening behavior. Driven by the dominant through-the-thickness failure under impact loading, a three-dimensional continuum damage model is implemented for the three-dimensional solid element via its explicit material model for Abaqus (VUMAT) to capture the effect of three-dimensional stress state and the interaction of matrix cracking and delamination. Abaqus’ restart analysis capability is used to activate the compression after impact analysis using the final damage state from the dynamic impact analysis. Both the dynamic failure and the compression after impact are demonstrated via a suite of verification examples followed by the sensitivity analysis using distinct impact configurations. The predictive capability of the proposed three-dimensional damage model is first verified using a static open-hole tension test. Applications of the damage model are then demonstrated for simulations of the dynamic drop-weight tests and compression after impact tests. A comparative study on the developed method is performed using the results predicted from the open-source CompDam. A sensitivity study is also performed to demonstrate the impact energy-dependent failure mode. The proposed model has shown its advantages in performing a quick assessment of impact damage and its effects on the residual compressive strength.

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.

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