New composite materials from natural hard fibers. 2. Fatigue studies and a novel fatigue degradation model

1983 ◽  
Vol 22 (4) ◽  
pp. 643-652 ◽  
Author(s):  
Hector Belmares ◽  
Arnoldo Barrera ◽  
Margarita Monjaras
Keyword(s):  
Composite Materials ◽  
Degradation Model

A novel creep-fatigue stiffness degradation model for composite materials

2020 ◽  
Vol 237 ◽  
pp. 111955 ◽  
Author(s):  
Seyed Sina Samareh-Mousavi ◽  
Fathollah Taheri-Behrooz
Keyword(s):  
Composite Materials ◽  
Stiffness Degradation ◽  
Degradation Model ◽  
Creep Fatigue

scholarly journals 3D Gradual Material Degradation Model for Progressive Damage Analyses of Unidirectional Composite Materials

2015 ◽  
Vol 2015 ◽  
pp. 1-11
Author(s):  
Libin Zhao ◽  
Tianliang Qin ◽  
Jianyu Zhang ◽  
Yuli Chen
Keyword(s):  
Composite Materials ◽  
Maximum Stress ◽  
Damage Model ◽  
Unidirectional Composite ◽  
Progressive Damage ◽  
Material Degradation ◽  
Fiber Failure ◽  
Degradation Model ◽  
Static Tensile ◽  
Closure Effect

A new 3D constitutive model for progressive damage analyses of unidirectional composite materials is presented, in which several important damage phenomena for the composite materials, such as the interfiber crack orientation, coupling of fiber failure and interfiber failure under longitudinal loads, closure effect for interfiber cracks, and longitudinal compressive behaviors under transversal constraints, have been considered comprehensively. A modified maximum stress failure criterion has been used for the damage onset prediction and a linear damage model has been adopted to establish the evolution rules of different damage. Numerical analyses with the model proposed have been implemented by using the subroutine UMAT in commercial software ABAQUS. Progressive damage analyses and static tensile experiments of a group of double-lap composite bolted joints have been carried out to validate the model proposed. Good agreements between the numerical and experimental results have been obtained.

Progressive Fatigue Life Prediction of Composite Materials Based on Residual Material Property Degradation Model

2020 ◽  
Author(s):  
J. Nakai-Chapman ◽  
Y. H. Park ◽  
J. Sakai
Keyword(s):  
Composite Materials ◽  
Material Property ◽  
Fatigue Failure ◽  
Failure Modes ◽  
Fatigue Behavior ◽  
Weight Ratio ◽  
Fatigue Loading ◽  
Matrix Cracking ◽  
Degradation Model ◽  
Residual Material

Abstract Anisotropic composite materials have been extensively utilized in mechanical, automotive, aerospace and other engineering areas due to high strength-to-weight ratio, superb corrosion resistance, and exceptional thermal performance. As the use of composite materials increases, determination of material properties, mechanical analysis and failure of the structure become important for the design of composite structure. In particular, the fatigue failure is important to ensure that structures can survive in harsh environmental conditions. The non-homogeneous character of composites induces diverse failure modes of the constituent including fiber fracture, matrix cracking, fiber-matrix interface failure, and delamination. Non-homogeneity of composite materials makes their fatigue behavior very complex in comparison with traditional engineering materials. In this study, a progressive damage theory is extended to simulate fatigue failure of composite laminates under fatigue loading conditions. A residual material property degradation model was employed to predict fatigue damage due to arbitrary stress ratio without performing excessive quantities of testing. This generalized residual material property degradation rule is implemented into user subroutine USDFLD in ABAQUS through which material degradation states are updated over the progressive fatigue loading. The present computational method is verified by comparing the simulated results with the experimental data available in the literature.

Comparative Microstructures of Ion Milled and Electrochemically Thinned Composite Materials

1974 ◽  
Vol 32 ◽  
pp. 546-547
Author(s):  
R.R. Russell
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Composite Materials ◽  
Great Difficulty ◽  
Ion Milling ◽  
Transmission Electron ◽  
Ion Damage ◽  
Intermetallic Composite

Transmission electron microscopy of metallic/intermetallic composite materials is most challenging since the microscopist typically has great difficulty preparing specimens with uniform electron thin areas in adjacent phases. The application of ion milling for thinning foils from such materials has been quite effective. Although composite specimens prepared by ion milling have yielded much microstructural information, this technique has some inherent drawbacks such as the possible generation of ion damage near sample surfaces.

Transmission electron microscopy of composite materials

1988 ◽  
Vol 46 ◽  
pp. 1012-1015
Author(s):  
K.P.D. Lagerlof
Keyword(s):  
Composite Materials ◽  
Physical Properties ◽  
Structural Defects ◽  
Structural Composites ◽  
Multiphase Materials ◽  
Structural Reinforcement ◽  
Transmission Electron ◽  
Reinforced Fiber ◽  
Particulate Reinforced Composites ◽  
Definition Of

Although most materials contain more than one phase, and thus are multiphase materials, the definition of composite materials is commonly used to describe those materials containing more than one phase deliberately added to obtain certain desired physical properties. Composite materials are often classified according to their application, i.e. structural composites and electronic composites, but may also be classified according to the type of compounds making up the composite, i.e. metal/ceramic, ceramic/ceramie and metal/semiconductor composites. For structural composites it is also common to refer to the type of structural reinforcement; whisker-reinforced, fiber-reinforced, or particulate reinforced composites [1-4].For all types of composite materials, it is of fundamental importance to understand the relationship between the microstructure and the observed physical properties, and it is therefore vital to properly characterize the microstructure. The interfaces separating the different phases comprising the composite are of particular interest to understand. In structural composites the interface is often the weakest part, where fracture will nucleate, and in electronic composites structural defects at or near the interface will affect the critical electronic properties.

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