A Computational Model for Predicting Damage Evolution in Laminated Composite Plates

1999 ◽  
Vol 121 (4) ◽  
pp. 436-444 ◽  
Author(s):  
M. L. Phillips ◽  
C. Yoon ◽  
D. H. Allen
Keyword(s):  
Finite Element ◽  
Fiber Composite ◽  
Composite Plates ◽  
Laminated Plates ◽  
Matrix Cracking ◽  
Interface Fracture ◽  
Zone Model ◽  
Desktop Computer ◽  
Multi Scale ◽  
Element Algorithm

A model is developed herein for predicting the evolution of interface degradation, matrix cracking, and delamination at multiple sites in laminated continuous fiber composite plates subjected to monotonic and/or cyclic mechanical loading. Due to the complicated nature of the many cracks and their interactions, a multi-scale micro-meso-local-global methodology is deployed in order to model all damage modes. Interface degradation is first modeled analytically on the microscale, and the results are homogenized to produce a cohesive zone model that is capable of predicting interface fracture. Subsequently, matrix cracking in the plies is modeled analytically on the meso-scale, and this result is homogenized to produce ply level damage dependent constitutive equations. The evolution of delaminations is considered on the local scale, and this effect is modeled using a three dimensional finite element algorithm. Results of this analysis are homogenized to produce damage dependent laminate equations. Finally, global response of the damaged plate is modeled using a plate finite element algorithm. Evolution of all three modes of damage is predicted via interfacing all four scales into a single multi-scale algorithm that is computationally tenable for use on a desktop computer. Results obtained herein suggest that this model may be capable of accurately predicting complex damage patterns such as that observed at open holes in laminated plates.

A cell-based smoothed finite element formulation for viscoelastic laminated composite plates considering hygrothermal effects

2020 ◽  
pp. 002199832098005
Author(s):  
Sy-Ngoc Nguyen ◽  
Tam T Truong ◽  
Maenghyo Cho ◽  
Nguyen-Thoi Trung
Keyword(s):  
Finite Element ◽  
Shear Deformation Theory ◽  
Laminated Composite ◽  
Composite Plates ◽  
Integral Form ◽  
Complex Stress ◽  
Laminated Plates ◽  
Element Formulation ◽  
Composite Laminated Plates ◽  
Smoothed Finite Element Method

In the present study, the viscoelastic analysis is investigated for composite laminated plates using a smoothed finite element method called cell/element based smoothed discrete shear gap method. Moreover, the hygrothermal effects is considered on the viscoelastic responses of composite laminated plates. The first-order shear deformation theory is employed due to its simplicity and accuracy. With the help of the convolution theorem in Laplace transformation, the complex stress-strain relationship in integral form is simplified to linear in transformed domain. Therefore, all computing procedures are performed in the transformed domain and then, using inverse techniques (Fast Fourier Transform) to converted back to the real-time domain. The study provides an effective computational tool to analyze the viscoelastic response of laminated composite taking into account the influence of the time and hygrothermal effects.

Investigation on Interlaminar Shear Stresses in Laminated Composite Plates under Thermal and Mechanical Loading

2014 ◽  
Vol 592-594 ◽  
pp. 451-455
Author(s):  
Nagaraj Murugesan ◽  
Vasudevan Rajamohan
Keyword(s):  
Finite Element ◽  
Thermal Environment ◽  
Laminated Composite ◽  
Composite Plates ◽  
Laminated Plates ◽  
Shear Stresses ◽  
Laminated Composite Plates ◽  
Interlaminar Stresses ◽  
Composite Laminated Plates ◽  
Interlaminar Shear

In this study the combined effect of thermal environment and mechanical loadings on the interlaminar shear stresses of both moderately thin and thick composite laminated plates are numerically analyzed. The finite element modeling of laminated composite plates and analysis of interlaminar stresses are performed using the commercially available software package MSC NASTRAN/PATRAN. The validity of the present finite element analysis is demonstrated by comparing the interlaminar stresses developed due to mechanical loadings derived using the present FEM with those of available literature. Various parametric studies are also performed to investigate the effect of thermal environment on interlaminar stresses generated in asymmetric cross-ply composite laminated plates of different length to thickness ratios (L/H) and boundary conditions with identical mechanical loadings. It is observed that the elevated thermal environment under identical mechanical loading lead to higher interlaminar shear stresses varying with length to depth ratio and boundary conditions in asymmetric cross-ply laminated composite plates.

Eigen Value Analysis of Glass Fiber Reinforced Composite Plate

2012 ◽  
Vol 488-489 ◽  
pp. 676-680
Author(s):  
Pramod Kumar ◽  
S.K. Tiwari
Keyword(s):  
Finite Element ◽  
Frequency Response ◽  
Composite Plate ◽  
Composite Plates ◽  
Laminated Plates ◽  
Fiber Reinforced ◽  
Fiber Reinforced Composite ◽  
Advanced Composite ◽  
Reinforced Composite ◽  
Quadrilateral Finite Element

Finite element analysis has been used to find out eigen values and mode shape for fiber reinforced composite plates. FRC plates are important structural elements in modern engineering structures. Vibrations of laminated composite plates have been the subject of significant research activities in recent years. Last two decades have witnessed continued development of advanced composite and other high performance aerospace materials with increased specific strength and modulus, longer fatigue life, higher combat survivability etc. Advanced composite laminates extend the possibility of optimal design through the variation of stacking sequence and fiber orientation, known as composite tailoring. The benefits that accrue from this are not attainable without solving the complexities that are introduced by various coupling effects, such as bending–stretching and bending-twisting. Even, as the matrix material is of relatively low shearing stiffness as compared to the fibers, a reliable prediction of frequency response of laminated plates must account for transverse shear deformation. A four noded quadrilateral finite element is considered for the study of frequency response of composite plate. An analytical solution to the boundary value problem of free vibration response of arbitrarily laminated plates subjected to an admissible boundary condition is presented. A rectangular fiber reinforced composite plate is modeled in FEM software (NISA 15) and natural frequencies, mode shapes are obtained and are compared with the available analytical solutions.

Simulation of Low Velocity Impact Test on Carbon/Epoxy Composite Plates

2015 ◽  
Vol 1115 ◽  
pp. 523-526
Author(s):  
Ziamah B. Buang ◽  
S.M. Kashif
Keyword(s):  
Numerical Simulation ◽  
Finite Element Analysis ◽  
Finite Element ◽  
Composite Structures ◽  
Composite Plates ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Element Analysis ◽  
Velocity Impact

Composite materials that have low weight and high strength properties are currently one of the promising materials for a vehicle’s body. However, the effect of low velocity impact on composite may cause failure through matrix cracking, fibre breakage and delamination which may reduce the structure strength. Low velocity impact can be analysed either by experimentation or numerical simulation. Numerical simulation which is also known as finite element analysis can show the degradation of the composite structure properties after an impact loading condition without doing any experimentation. Thus, in this paper, LS-DYNA is the finite element analysis software that is used to simulate a low velocity impact on composite structures.

scholarly journals A new finite element for free vibration analysis of stiffened composite plates

2007 ◽  
Vol 29 (4) ◽  
pp. 529-538 ◽  
Author(s):  
Tran Ich Thinh ◽  
Ngo Nhu Khoa
Keyword(s):  
Finite Element ◽  
Free Vibration ◽  
Vibration Analysis ◽  
Plate Theory ◽  
Free Vibration Analysis ◽  
Composite Plates ◽  
Laminated Plates ◽  
Triangular Element ◽  
Plate Element ◽  
Stiffened Plate

A new 6-noded stiffened triangular plate element for the analysis of stiffened composite plates based on Mindlins deformation plate theory has been developed. The stiffened plate element is a combination of basic triangular element and bar component. The element can accommodate any number of arbitrarily oriented stiffeners and obviates the use of mesh lines along the stiffeners. Free vibration analyses of stiffened laminated plates have been carried out with this element and the results are compared with those published. The finite element results show very good matching with the experimental ones.

Probabilistic Response of Composite Plates for Damage Initiation due to Low Velocity Impact

2018 ◽  
Author(s):  
Shivdayal Patel ◽  
Suhail Ahmad
Keyword(s):  
Composite Plates ◽  
Laminated Plates ◽  
International Standards ◽  
Matrix Cracking ◽  
Low Velocity Impact ◽  
Stochastic Response ◽  
Low Velocity ◽  
Fiber Failure ◽  
Velocity Impact ◽  
Damage Initiation

The low velocity impact (LVI) result of laminated targets is an imperative study to evaluate its failure for applications to inconsequential structures. The work has extensive applications to off shore and naval industry. Safety and reliability assessment as per the international standards is one of the basic objectives of the study. LVI on composite plates is performed taking the material parameters and loading condition as random variables. Graphite fiber reinforced laminated plates are vulnerable to damage due to impact by foreign objects and in plane loading. In order to evaluate the safe load carrying capacity and the reliability under impact, dynamic analysis of composite plate subjected to LVI is carried out. Probabilistic finite element method (PFEM) is performed to determine the stochastic response. During impact, the in-plane damage modes such as matrix cracking, fiber failure and shear cracking are modeled using a failure criterion. The out of plane de-lamination is modeled using cohesive surfaces. The randomness associated with the system properties due to the inherent scatter in the geometric and material properties and input loads are modeled in a stochastic fashion. Random parameters represent various characteristics appearing in the performance function. The stochastic response and reliability forecast of the system is determined by Gaussian processes response surface method (GPRSM) and validity of method for the present problem is establish using Monte Carlo simulation (MCS) procedure. The safety level qualification is achieved in terms of reliability level targeted.

The Effect of Fiber Type on the Level of Stress Concentration Created by U-Notches in Long-Fiber Composite Plates

1993 ◽  
Author(s):  
A. Turgut ◽  
N. Arsian ◽  
Erol Sancaktar
Keyword(s):  
Finite Element ◽  
Stress Concentration ◽  
Fiber Type ◽  
Fiber Composite ◽  
Composite Plates ◽  
The Finite Element Method ◽  
Notch Stress ◽  
Typical Material ◽  
Fiber Reinforcements ◽  
Stress Concentration Factors

Abstract The effect of fiber type on the level of stress concentration created by u-notches were investigated for unidirectional and symmetric cross-ply laminates loaded on or off-axis. The finite element method was used for this purpose utilizing triangular elements under plane stress conditions. Analyses were performed for three different fiber reinforcements of epoxy matrix: glass, graphite and boron. Typical material properties reported in the literature for glass/epoxy, boron/epoxy and graphite/epoxy were used in calculations. The accuracy of the finite element code utilized was first checked by calculating the u-notch stress concentration factors for an isotropic steel plate.

Numerical Modelling of Damage Progression in Single-Fiber Composite under Axial Tension

2011 ◽  
Vol 268-270 ◽  
pp. 280-285
Author(s):  
Dong Min Yang ◽  
Yong Sheng ◽  
Jian Qiao Ye ◽  
Yuan Qiang Tan ◽  
Sheng Qiang Jiang
Keyword(s):  
Numerical Models ◽  
Fiber Composite ◽  
Failure Process ◽  
Matrix Cracking ◽  
Single Fiber ◽  
Zone Model ◽  
Particle Assembly ◽  
Damage And Failure ◽  
Axial Tension ◽  
Dem Model

Damage and failure of the fiber reinforced composites remain as a challenging research subject in the area of material science and engineering. In this study a novel particle assembly model is developed using two dimensional Discrete Element Method (DEM) for the purpose of simulating the damage and failure process of the single-fiber composite (SFC) under axial tension. Fiber (SiC) and matrix (Epoxy) are represented by particles bonded together through elastic parallel bonds which are calibrated by a series of numerical tests. The contacts between the fiber particles and matrix particles are directly accounted for the fiber/matrix interface which is represented by the contact softening model similar to the cohesive zone model (CZM) in the continuum mechanics. The single-fiber composite tensile test is carried out using the developed DEM model in order to evaluate the interactions between fiber breakage, interfacial debonding and matrix cracking. The numerical results have demonstrated the capability of the developed DEM model in simulating the entire failure process of each individual constituent of the single fiber composite. This study has also confirmed that the DEM model has unique advantages over the conventionally numerical models in terms of dealing with the evolution of microscopic damages in composite materials.

Small-Amplitude Free-Vibration Analysis of Piezoelectric Composite Plates Subject to Large Deflections and Initial Stresses

2005 ◽  
Vol 128 (1) ◽  
pp. 41-49 ◽  
Author(s):  
Dimitris Varelis ◽  
Dimitris A. Saravanos
Keyword(s):  
Finite Element ◽  
Small Amplitude ◽  
Natural Frequencies ◽  
Free Vibration Analysis ◽  
Composite Plates ◽  
Nonlinear Effects ◽  
Laminated Plates ◽  
Initial Stresses ◽  
Piezoelectric Composite ◽  
Piezoceramic Actuator

A coupled theoretical and computational framework is presented for analyzing the small amplitude-free vibrational response of composite laminated plates with piezoelectric actuators and sensors, subject to nonlinear effects due to large rotations and initial stresses. Coupled laminate mechanics incorporating nonlinear governing equations with mixed-field shear-layerwise assumptions for the piezoelectric laminate are implemented. A finite element method is formulated to yield the linearized discrete dynamic equations of a piezocomposite plate on top of its nonlinear electrostatic response, and a novel eight-node coupled nonlinear plate finite element forms the basis of numerical analyses. The natural frequencies in a beam with a piezoceramic actuator and sensor subject to in-plane mechanical loading, high enough to induce buckling and postbuckling are also experimentally characterized, and comparisons to numerical results show excellent correlation. Additional numerical evaluations quantify the active shifting of natural frequencies in adaptive beams and plates subject to high out-of-plane and in-plane electromechanical loading, and the variation of modal frequencies during buckling and postbuckling response. Finally, the possibility to detect and actively manage buckling in adaptive piezocomposite plates is illustrated.

A Software of Pre-Buckling Analysis of Laminated Plates and Shells Based on Stiffness Matrix Determinant

2013 ◽  
Vol 712-715 ◽  
pp. 1075-1079
Author(s):  
Zai Ling Cheng ◽  
Cheng Shuang Han ◽  
Hong Mei Zhang
Keyword(s):  
Finite Element Analysis ◽  
Finite Element ◽  
Stiffness Matrix ◽  
Composite Plates ◽  
Computational Procedure ◽  
Laminated Plates ◽  
Computational Time ◽  
Analysis Model ◽  
Element Analysis ◽  
Plates And Shells

The development of computer technology has provided advanced methods for the analysis of complex mechanics problems. Along with the enhancement of computer speed, the computational time used in a finite element analysis is reduced significantly. The main work in a pre-bucking finite element analysis will concentrate on structuring the analytical model and the software model. A normalized factor of the normalized determinant DET of stiffness matrix is defined in this article.The finite element analysis model used in the pre-bucking analysis of laminated composite plates and shells is presented based on the characteristic of the DET. An algorithm for controlling computational procedure and determining critical load is also presented. Numerical examples are given to validate the proposed method and satisfactory results are obtained.

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