Three-Dimensional Continuum Damage Model for Polymer Matrix Composites

Materials ◽  
2004 ◽  
Author(s):  
Ever J. Barbero ◽  
Joan A. Mayugo ◽  
Paolo Lonetti

A constitutive model for fiber reinforced composite materials with damage and unrecoverable deformation, which for the first time accounts for thru-the-thickness damage, is presented. The formulation is based on Continuous Damage Mechanics coupled with Classical Plasticity Theory in a consistent thermodynamic framework using internal state variables. A novel formulation of the parameter identification is included in order to describe the main failure modes of polymer matrix composite laminae. The new parameter identification is simpler than those available in the literature. It is also more sensitive and allows for better control of material behavior to match experimental data. Furthermore, it uses material properties that are simpler to test than previous models. The model uses a small number of adjustable parameters, which are identified from available experimental data. Comparisons with experimental data for composite laminates under in plane and torsion loading are shown to validate the model. The new model, although simpler than previous ones, is able to model all experimentally observed behavior of laminates that were previously modeled with more complex models.

1990 ◽  
Vol 43 (7) ◽  
pp. 131-151 ◽  
Author(s):  
Sanda Cleja T¸igoiu ◽  
Eugen Soo´s

We present the microstructural basis, the initial macroscopical formulations, and a possible axiomatic reconstruction of the elastoviscoplastic model for metals based on the use of the local, current, relaxed configurations. Structural analysis and experimental data show that using these configurations offers advantages for the formulation of the material laws when the deformations are small or moderately large. Our review aims to be a concise, historical, and critical exposition of the main stages, contributions and results, which led, during the late sixties and the beginning of seventies, to the formulation of the fundamental ideas lying at the basis of the model. We delineate the role played by Lee, Liu, Teodosiu, Sidoroff, Mandel, and Kratochvil in the first formulation of the theory between 1966 and 1972, as well as the contributions of Dafalias and Loret to the development of the model between 1983 and 1985. Finally, we discuss some results obtained between 1985 and 1988 with models based on local current relaxed configurations.


2021 ◽  
Author(s):  
Alireza Sayyidmousavi

Polymer matrix composites (PMC’s) are widely used in critical aerospace structures due to their numerous advantageous mechanical properties. Recently, PMC’s have been considered for high temperature applications where viscoelasticity arising from the time dependent nature of the polymer matrix becomes an important consideration. This inherent viscoelasticity can significantly influence deformation, strength and failure response of these materials under different loading modes and environmental factors. With a potentially large number of plies of different fiber directions and perhaps material properties, determining a fatigue failure criterion of any degree of generality through experiments only, may seem to be an unrealistic task. This difficult situation may be mitigated through the development of suitable theoretical micro or macro mechanical models that are founded on considering the fatigue failure of the constituting laminas. The micro‐approach provides a detailed examination of the individual failure modes in each of the constituent materials i.e. fiber, matrix. In this work, a micromechanical approach is used to study the role of viscoelasticity on the fatigue behavior of polymer matrix composites. In particular, the study examines the interaction of fatigue and creep in polymer matrix composites. The matrix phase is modeled as a vicoelastic material using Schapery’s single integral constitutive equation. Taking viscoelsticity into account allows the study of creep strain evolution during the fatigue loading. The fatigue failure criterion is expressed in terms of the fatigue failure functions of the constituent materials. The micromechanical model is also used to calculate these fatigue failure functions from the knowledge of the S‐N diagrams of the composite material in longitudinal, transverse and shear loadings thus eliminating the need for any further experimentation. Unlike the previous works, the present study can distinguish between the strain evolution due to fatigue and creep. The results can clearly show the contribution made by the effect of viscoelasticity to the total strain evolution during the fatigue life of the specimen. Although the effect of viscoelsticity is found to increase with temperature, its contribution to strain development during fatigue is compromised by the shorter life of the specimen when compared to lower temperatures.


2014 ◽  
Vol 566 ◽  
pp. 463-467
Author(s):  
Pu Xue ◽  
H.H. Chen ◽  
W. Guo

This paper studies the impact damage under low velocity impact for composite laminates based on a nonlinear progressive damage model. Damage evolution is described by the framework of the continuum damage mechanics. The real impact damage status of composite laminates has been used to analyze the residual compressive strength instead of assumptions on damage area after impact. The validity of the methodologies has been demonstrated by comparing the numerical results with the experimental data available in literature. The delamination area has an error of 11.3%. The errors of residual strength and compressive displacement are 8.9% and 15%, which indicate that the numerical results matched well with the experimental data.


2014 ◽  
Vol 513-517 ◽  
pp. 235-237
Author(s):  
Shi Yang Zhao ◽  
Pu Xue

In order to effectively describe the damage process of composite laminates and reduce the complexity of material model, a mixed damage model based on Linde Criteria and Hashin Criteria is proposed for prediction of impact damage in the study. The mixed damage model can predict baisc failure modes, including fiber fracture, matrix tensile damage, matrix compressive damage. Fiber damage and matrix damage in compression are described based on the progressive damage mechanics; and matrix damage in tension is described based on Continuous Damage Mechanics (CDM). Meanwhile, for interlaminar delamination, damage is described by cohesive model. A finite element model is established to analyze the damage process of composite laminate. A good agreement is got between damage predictions and experimental results.


1999 ◽  
Vol 121 (5) ◽  
pp. 533-541 ◽  
Author(s):  
M. T. Fondrk ◽  
E. H. Bahniuk ◽  
D. T. Davy

To describe the time-dependent nonlinear tensile behavior observed in experimental studies of cortical bone, a damage model was developed using two internal state variables (ISV’s). One ISV is a damage parameter that represents the loss of stiffness. A rule for the evolution of this ISV was defined based on previously observed creep behavior. The second ISV represents the inelastic strain due to viscosity and internal friction. The model was tested by simulating experiments in tensile and bending loading. Using average values from previous creep studies for parameters in the damage evolution rule, the model tended to underestimate the maximum nonlinear strains and to overestimate the nonlinear strain accumulated after load reversal in the tensile test simulations. Varying the parameters for the individual tests produced excellent fits to the experimental data. Similarly, the model simulations of the bending tests could produce excellent fits to the experimental data. The results demonstrate that the 2-ISV model combining damage (stiffness loss) with slip and viscous behavior could capture the nonlinear tensile behavior of cortical bone in axial and bending loading.


2018 ◽  
Vol 1148 ◽  
pp. 37-42
Author(s):  
Vemu Vara Prasad ◽  
Tanna Eswara Rao

Now a day’s eco-friendly natural fiber used as the reinforcement for the fabrication of the light weight, lower cost and biodegradable polymer matrix composites. One of such available natural reinforcement for the composite material is basalt fiber. The present paper gives a review on how the basalt fiber reinforced polymer matrix composite behave when they are adhesively, riveted and hybrid joined with other reinforcements such as aluminum, which is used for the particular or other applications and which joint gives better efficiency , suited for given application were discussed and the three joining techniques were investigated. Behavior of basalt fiber reinforced composites for the frequencies at which frequencies the failures like adhesive failure, light fiber tear, and mixed failure modes will occur. These three types of failure modes are investigated with the help of acoustic emission monitoring system.


2021 ◽  
Author(s):  
JAVIER BUENROSTRO ◽  
HYONNY KIM ◽  
ROBERT K. GOLDBERG ◽  
TRENTON M. RICKS

The need for advanced material models to simulate the deformation, damage, and failure of polymer matrix composites under impact conditions is becoming critical as these materials are gaining increased usage in the aerospace and automotive industries. The purpose of this work is to characterize carbon epoxy fabrics for composite material models that rely on a large number of input parameters to define their nonlinear and 3D response; e.g. elastic continuum damage mechanics models or plasticity damage models [1, 2]. It is challenging to obtain large sets of experimental stress-strain curves, therefore, careful selection of physical experiments that exhibit nonlinear behavior is done to significantly reduce the cost of generating threedimensional material databases. For this work, plain weave carbon fabrics with 3k and 12k tows are manufactured by VARTM. Testing is done using MTS hydraulic test frames and 2D digital image correlation (DIC) to obtain experimental stress-strain curves for in-plane tension and shear as well as transverse shear. For cases where actual experimental data is either not available or difficult to obtain, the required model input is virtually generated using the NASA Glenn developed Micromechanics Analysis Method/Generalized Method of Cells (MAC/GMC) code. A viscoplastic polymer model is calibrated and utilized to model the matrix constituent within a repeating unit cell (RUC) of a plain weave carbon fiber fabric. Verification and validation of this approach is done using MAT213, a tabulated orthotropic material model in the finite element code LS-DYNA, which relies on 12 input stress-strain curves in various coordinate directions [2]. Based on the model input generated by the micromechanics analyses in combination with available experimental data, a series of coupon level verification and validation analyses are carried out using the MAT 213 composite model.


2017 ◽  
Vol 121 (1238) ◽  
pp. 515-532 ◽  
Author(s):  
N. Li ◽  
P.H. Chen ◽  
Q. Ye

ABSTRACTA method was developed to predict numerically the damage of composite laminates with multiple plies under low-velocity impact loading. The Puck criterion for 3D stress states was adopted to model the intralaminar damage including matrix cracking and fibre breakage, and to obtain the orientation of the fracture plane due to matrix failure. According to interlaminar delamination mechanism, a new delamination criterion was proposed. The influence of transverse and through-thickness normal stress, interlaminar shear stress and damage conditions of adjacent plies on delamination was considered. In order to predict the impact-induced damage of composite laminates with more plies quickly and efficiently, an approach, which can predict the specific damage of several plies in a single solid element, was proposed by interpolation on the strains of element integration points. Moreover, the proposed model can predict specific failure modes. A good agreement between the predicted delamination shapes and sizes and the experimental results shows correctness of the developed numerical method for predicting low-velocity impact damage on composite laminates.


2021 ◽  
Author(s):  
Alireza Sayyidmousavi

Polymer matrix composites (PMC’s) are widely used in critical aerospace structures due to their numerous advantageous mechanical properties. Recently, PMC’s have been considered for high temperature applications where viscoelasticity arising from the time dependent nature of the polymer matrix becomes an important consideration. This inherent viscoelasticity can significantly influence deformation, strength and failure response of these materials under different loading modes and environmental factors. With a potentially large number of plies of different fiber directions and perhaps material properties, determining a fatigue failure criterion of any degree of generality through experiments only, may seem to be an unrealistic task. This difficult situation may be mitigated through the development of suitable theoretical micro or macro mechanical models that are founded on considering the fatigue failure of the constituting laminas. The micro‐approach provides a detailed examination of the individual failure modes in each of the constituent materials i.e. fiber, matrix. In this work, a micromechanical approach is used to study the role of viscoelasticity on the fatigue behavior of polymer matrix composites. In particular, the study examines the interaction of fatigue and creep in polymer matrix composites. The matrix phase is modeled as a vicoelastic material using Schapery’s single integral constitutive equation. Taking viscoelsticity into account allows the study of creep strain evolution during the fatigue loading. The fatigue failure criterion is expressed in terms of the fatigue failure functions of the constituent materials. The micromechanical model is also used to calculate these fatigue failure functions from the knowledge of the S‐N diagrams of the composite material in longitudinal, transverse and shear loadings thus eliminating the need for any further experimentation. Unlike the previous works, the present study can distinguish between the strain evolution due to fatigue and creep. The results can clearly show the contribution made by the effect of viscoelasticity to the total strain evolution during the fatigue life of the specimen. Although the effect of viscoelsticity is found to increase with temperature, its contribution to strain development during fatigue is compromised by the shorter life of the specimen when compared to lower temperatures.


Author(s):  
C. L. Chow ◽  
F Yang ◽  
H. E. Fang

This paper presents the first part of a comprehensive mechanics approach capable of predicting the integrity and reliability of solder joint material under fatigue loading without viscoplastic damage considerations. A separate report will be made to present the comprehensive damage model describing life prediction of the solder material under thermomechanical fatigue (TMF) loading. The method is based on the theory of damage mechanics, which makes possible a macroscopic description of the successive material deterioration caused by the presence of microcracks/voids in engineering materials. A damage mechanics model based on the thermodynamic theory of irreversible processes with internal state variables is proposed and used to provide a unified approach in characterizing the cyclic behaviour of a typical solder material. With the introduction of a damage effect tensor, the constitutive equations are derived to enable the formulation of a fatigue damage dissipative potential function and a fatigue damage criterion. The fatigue evolution is subsequently developed on the basis of the hypothesis that the overall damage is induced by the accumulation of fatigue and plastic damage. This damage mechanics approach offers a systematic and versatile means that is effective in modelling the entire process of material failure, ranging from damage initiation and propagation leading eventually to macrocrack initiation and growth. As the model takes into account the load history effect and the interaction between plasticity damage and fatigue damage, with the aid of a modified general-purpose finite element program, the method can readily be applied to estimate the fatigue life of solder joints under different loading conditions.


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