scholarly journals Failure of a Fiber Composite Lamina Under Three-Dimensional Stresses

1999 ◽  
Author(s):  
Steven J. DeTeresa
Keyword(s):  
Fiber Composite ◽  
Three Dimensional ◽  
Uniaxial Stress ◽  
Failure Criteria ◽  
Fiber Composites ◽  
Test System ◽  
Failure Model ◽  
Pressure Test ◽  
Using Data ◽  
Carbon Fiber Epoxy

Abstract The efficient use of thick-section fiber composites requires a proven three-dimensional failure model. Numerous failure criteria have been proposed, but the lack of critical experimental results makes it difficult to assess the accuracy of these models. It is shown that the various predictions for failure of a lamina due to the simple state of uniaxial stress plus superposed hydrostatic pressure are disparate. These differences are sufficient to allow evaluation of failure criteria using data that has the normal scatter found for composite materials. A high-pressure test system for fiber composites is described and results for the effects of pressure on the transverse and longitudinal compression strengths of a carbon fiber/epoxy lamina are discussed. Results are compared with a few representative failure models.

Failure Criteria for Unidirectional Fiber Composites

1980 ◽  
Vol 47 (2) ◽  
pp. 329-334 ◽  
Author(s):  
Z. Hashin
Keyword(s):  
Stress State ◽  
Failure Modes ◽  
Three Dimensional ◽  
Transversely Isotropic ◽  
Failure Surface ◽  
Failure Criteria ◽  
Fiber Composites ◽  
Piecewise Smooth ◽  
Average Stress ◽  
Unidirectional Fiber

Three-dimensional failure criteria of unidirectional fiber composites are established in terms of quadratic stress polynomials which are expressed in terms of the transversely isotropic invariants of the applied average stress state. Four distinct failure modes—tensile and compressive fiber and matrix modes—are modeled separately, resulting in a piecewise smooth failure surface.

Fatigue Failure Criteria for Unidirectional Fiber Composites

1981 ◽  
Vol 48 (4) ◽  
pp. 846-852 ◽  
Author(s):  
Z. Hashin
Keyword(s):  
Fatigue Failure ◽  
Failure Modes ◽  
Three Dimensional ◽  
Transversely Isotropic ◽  
Failure Criteria ◽  
Fiber Composites ◽  
Cyclic Stress ◽  
Unidirectional Fiber ◽  
Single Stress ◽  
Material Information

Three-dimensional fatigue failure criteria for unidirectional fiber composites under states of cyclic stress are established in terms of quadratic stress polynomials which are expressed in terms of the transversely isotropic invariants of the cyclic stress. Two distinct fatigue failure modes, fiber mode, and matrix mode, are modeled separately. Material information needed for the failure criteria are the S-N curves for single stress components. A preliminary approach to incorporate scatter into the failure criteria is presented.

Development of a PZT Fiber/Piezo-Polymer Composite Actuator With Interdigitated Electrodes

2001 ◽  
Author(s):  
Cheol Kim ◽  
Kun-Hyung Koo
Keyword(s):  
Composite Plate ◽  
Effective Properties ◽  
Fiber Composite ◽  
Matrix Material ◽  
Three Dimensional ◽  
Fiber Composites ◽  
Numerical Analyses ◽  
Interdigitated Electrodes ◽  
Composite Actuator ◽  
Piezoelectric Fiber

Abstract Piezoelectric Fiber Composites with Interdigitated Electrodes (PFCIDE) were previously introduced as an alternative to monolithic wafers with conventional electrodes for applications of structural actuation. This paper is an investigation into the performance improvement of piezoelectric fiber composite actuators by changing the matrix material. This paper presents a modified micro-electromechanical model and numerical analyses of piezoelectric fiber/piezopolymer matrix composite actuator with interdigitated electrodes (PFPMIDE). Various concepts from different backgrounds including three-dimensional linear elastic and dielectric theories have been incorporated into the present linear piezoelectric model. The rule of mixture and the modified method to calculate effective properties of fiber composites were extended to apply to the PFPMIDE model. The new model was validated comparing with available experimental data and other analytical results. To see the structural responses of a composite plate integrated with the PFPMIDE, three-dimensional finite element formulations were derived. Numerical analyses show that the shape of the graphite/epoxy composite plate with the PFPMIDE may be controlled by judicious choice of voltages, piezoelectric fiber angles, and elastic tailoring of the composite plate.

Large deformation mechanical modeling with bilinear stiffness for Macro-Fiber Composite bimorph based on extending mixing rules

2020 ◽  
pp. 1045389X2095125
Author(s):  
Kai-ming Hu ◽  
Hua Li
Keyword(s):  
Finite Element ◽  
Finite Element Model ◽  
Large Deformation ◽  
Composite Structures ◽  
Fiber Composite ◽  
Three Dimensional ◽  
Element Model ◽  
Fiber Composites ◽  
Mixing Rules ◽  
Macro Fiber Composite

Macro-Fiber Composite bimorph is a kind of piezoelectric actuator that allow large bending deformation. However, macro-fiber composites exhibit strong stiffness nonlinearity in their operation range, so it is difficult to accurately estimate their large deformation behavior based on a linear constitutive model. In addition, the macro-fiber composites have active and inactive parts, that significantly differ in their material sizes and properties, so it is not reasonable to consider them as uniform material. Thus, it is necessary develop an accurate modeling and analysis method for the large deformation macro-fiber composite structures. First, the mixing rules are extended to derive the three-dimensional homogenized mechanical and electrical parameters of the macro-fiber composite active part; based on these parameters, the actuation results of linear finite element model is in good agreement with the official data. Then a finite element model of the axially compressed macro-fiber composite bimorph is established, the bilinear tensile stiffness of macro-fiber composite is realized by secondary development in ANSYS. Comparison with the experimental results reveals high accuracy of the established finite element model. Thus, the developed method can be effectively used for the performance evaluation and design of the macro-fiber composite devices with large deformation.

A Three-Dimensional Constitutive Theory for Fiber Composite Laminated Media

1990 ◽  
Vol 57 (4) ◽  
pp. 948-955 ◽  
Author(s):  
R. M. Christensen ◽  
E. Zywicz
Keyword(s):  
Fiber Composite ◽  
Three Dimensional ◽  
Transversely Isotropic ◽  
Constitutive Theory ◽  
Constitutive Relationship ◽  
Elastic Behavior ◽  
Specific Subset ◽  
The Matrix ◽  
Scale Properties ◽  
Using Data

A three-dimensional elastic constitutive theory is developed for application to fiber composite laminated media. The lamina level constitutive relationship is a specific subset of general, transversely isotropic media behavior. This special class of lamina behavior permits the development of an exact lamination procedure for systems assembled from a single lamina type. The three-dimensional constitutive form for the laminate is determined in terms of the subscale lamina properties and the orientations of each lamina. The extension of this specific constitutive relationship to general transversely isotropic lamina involves separation of the five lamina-scale properties into fiber-dominated versus matrix-dominated classifications and the development of a generalized averaging procedure for the matrix-dominated properties. The resulting three-dimensional constitutive/lamination theory is evaluated through comparisons between exact solutions, using data bases appropriate for graphite and glass epoxy systems in quasi-isotropic layups. The theory remains highly effective through the transition from thin laminate to thick laminate behavior and even beyond that through the transition from thick laminate behavior to fully and strongly three-dimensional elastic behavior. The generalized averaging procedure for the matrix-dominated properties produces variations in results that are the same or less than the variations in results due to the experimental uncertainty in the matrix-dominated properties themselves. The theory is fairly simple and extremely versatile in its application.

Failure Theory/Failure Criteria for Fiber Composite Laminates

2016 ◽  
Vol 84 (2) ◽  
Author(s):  
Richard M. Christensen ◽  
Kuldeep Lonkar
Keyword(s):  
Composite Laminates ◽  
Fiber Composite ◽  
Failure Criteria ◽  
Fiber Composites ◽  
Failure Envelope ◽  
Related Matter ◽  
Failure Theory ◽  
Testing Data ◽  
Failure Properties ◽  
Theory Failure

Failure criteria are derived for the case of a quasi-isotropic laminate and for the more general case of orthotropic laminates. The former requires two calibrating failure properties obtained directly from laminate testing and the latter requires five standard experimental measurements for its calibration. Then the quasi-isotropic failure theory is taken much further, also admitting full calibration by only the two composites tow failure properties, the associated unidirectional tensile, and compressive strengths. The theoretically predicted failure envelope for the quasi-isotropic laminate is favorably compared with some comprehensive testing data. As a related matter, the general failure criteria for unidirectional fiber composites are also reviewed.

Three-Dimensional Numerical Simulation of Random Fiber Composites With High Aspect Ratio and High Volume Fraction

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Bo Cheng Jin ◽  
Assimina A. Pelegri
Keyword(s):  
Aspect Ratio ◽  
Volume Fraction ◽  
Fiber Composite ◽  
Three Dimensional ◽  
High Volume ◽  
Fiber Composites ◽  
High Volume Fraction ◽  
Fiber Networks ◽  
Representative Volume ◽  
Representative Volume Elements

Organic and inorganic fiber reinforced composites with various fiber orientation distributions and fiber geometries are abundantly available in several natural and synthetic structures. Inorganic glass fiber composites have been introduced to numerous applications due to their economical fabrication and tailored structural properties. Numerical characterization of such composite materials is necessitated due to their intrinsic statistical nature, since elaborate experiments are prohibitively costly and time consuming. In this work, representative volume elements of unidirectional random filaments and fibers are numerically developed in PYTHON to enhance accuracy and efficiency of complex geometric representations encountered in random fiber networks. A modified random sequential adsorption algorithm is applied to increase the volume fraction of the representative volume elements, and a spatial segment shortest distance algorithm is introduced to construct a 3D random fiber composite with high fiber aspect ratio (100:1) and high volume fraction (31.8%). For the unidirectional fiber networks, volume fractions as high as 70% are achieved when an assortment of circular fiber diameters are used in the representative volume element.

scholarly journals Mechanical Properties of Epoxy and Its Carbon Fiber Composites Modified by Nanoparticles

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Fang Liu ◽  
Shiqiang Deng ◽  
Jianing Zhang
Keyword(s):  
Carbon Fiber ◽  
Composite Laminates ◽  
Fiber Composite ◽  
Fiber Composites ◽  
Epoxy Composites ◽  
Compressive Property ◽  
Carbon Fiber Composites ◽  
Carbon Fiber Composite ◽  
Compressive Performance ◽  
Carbon Fiber Epoxy

Compressive properties are commonly weak parts in structural application of fiber composites. Matrix modification may provide an effective way to improve compressive performance of the composites. In this work, the compressive property of epoxies (usually as matrices of fiber composites) modified by different types of nanoparticles was firstly investigated for the following study on the compressive property of carbon fiber reinforced epoxy composites. Carbon fiber/epoxy composites were fabricated by vacuum assisted resin infusion molding (VARIM) technique using stitched unidirectional carbon fabrics, with the matrices modified with nanosilica, halloysite, and liquid rubber. Testing results showed that the effect of different particle contents on the compressive property of fiber/epoxy composites was more obvious than that in epoxies. Both the compressive and flexural results showed that rigid nanoparticles (nanosilica and halloysite) have evident strengthening effects on the compression and flexural responses of the carbon fiber composite laminates fabricated from fabrics.

Progressive damage and failure modeling in composite cylindrical pyramidal lattice structure

2020 ◽  
Vol 234 (12) ◽  
pp. 1515-1525
Author(s):  
Masoud Mohammadi ◽  
Ali Sadeghi
Keyword(s):  
Experimental Test ◽  
Lattice Structure ◽  
Fiber Composite ◽  
Compressive Loading ◽  
Three Dimensional ◽  
Experimental Tests ◽  
Failure Criteria ◽  
Progressive Damage ◽  
Carbon Fiber Composite ◽  
Damage Functions

In this paper, the mechanical behavior of a carbon fiber composite cylindrical pyramidal lattice structure has been predicted based on initial failure criteria and progressive damage under compressive loading. For this purpose, the three-dimensional Hashin failure criteria with instantaneous and gradual unloading models have been employed by the user subroutine UMAT in ABAQUS/Standard. In the instantaneous and gradual unloading models, progressive damage has been controlled by binary and exponential damage functions, respectively. Besides, to validate finite element models, the results have been compared with the experimental tests. Therefore, a new mold has been designed and manufactured for the experimental test of composite cylindrical pyramidal lattice structures. The new mold allows the use of the maximum inherent strength of the fiber-reinforced composite. The predicted force–displacement curves are in good agreement with the experimental test results. Hence, it is possible to use these FE models in the design of ultra-lightweight structures.

2013 Timoshenko Medal Award Paper—Completion and Closure on Failure Criteria for Unidirectional Fiber Composite Materials

2013 ◽  
Vol 81 (1) ◽  
Author(s):  
Richard M. Christensen
Keyword(s):  
Composite Materials ◽  
Fiber Composite ◽  
Failure Criteria ◽  
Fiber Composites ◽  
Polynomial Invariants ◽  
Unidirectional Fiber ◽  
Detailed Evaluation ◽  
Unidirectional Fiber Composite ◽  
Failure Properties ◽  
Fiber Composite Materials

Building upon previous work, the failure criterion for unidirectional fiber composite materials is examined using a sensitivity analysis as applied to its transverse, matrix controlled failure properties. A new and general relationship is found between these three properties thereby reducing the total number of independent properties needed to calibrate the theory to five. This completes and closes the development of failure criteria for unidirectional fiber composites by the polynomial invariants method. A broad but detailed evaluation of the resulting failure criteria is given. Future applications for these new failure criteria are discussed.

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