Failure Theory/Failure Criteria for Fiber Composite Laminates

2016 ◽  
Vol 84 (2) ◽  
Author(s):  
Richard M. Christensen ◽  
Kuldeep Lonkar

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.

2013 ◽  
Vol 81 (1) ◽  
Author(s):  
Richard M. Christensen

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.


2017 ◽  
Vol 84 (10) ◽  
Author(s):  
Richard M. Christensen

An applications methodology is synthesized from the research-based development of failure theory for orthotropic fiber composite laminates. In effect, this work continues and completes the work of Christensen (2017, “Lamination Theory for the Strength of Fiber Composite Materials,” ASME J. Appl. Mech., 84(7), p. 071007). This failure theory applies for the condition of fiber-dominated behavior, appropriate to carbon fiber—polymeric matrix composites and such similar systems. A lamination theory for stiffness and a separate lamination theory for strength are the outcomes derived here. Final forms are given for 0, 90, ± 45 type orthotropic laminates, with the four lamina orientation volume fractions to be specified in any particular application of interest. Many examples are given of using the new methodology in specific design cases.


1999 ◽  
Author(s):  
Steven J. DeTeresa

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.


2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Fang Liu ◽  
Shiqiang Deng ◽  
Jianing Zhang

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.


2020 ◽  
Vol 980 ◽  
pp. 107-116
Author(s):  
Hong Wang Zhao ◽  
Xiao Gang Liu ◽  
Abraham Kent

This paper expounds the basic theory of composite mechanics, and discusses the damage forms, damage analysis and failure criteria of composite materials. Then, the basic mechanical properties of unidirectional CFRP laminates with different layers, including modulus of elasticity, strength and so on, were obtained through a large number of experiments. Based on the experimental data, the relationship between the number of layers and the properties of materials was studied. The brittle fracture process of CFRP laminates was simulated by finite element analysis based on progressive damage model and compared with the force-displacement curves obtained by experiments. The validity of progressive damage model was proved.


2013 ◽  
Vol 858 ◽  
pp. 32-39 ◽  
Author(s):  
Wan Ahmad Dahalan Wan Dalina ◽  
M. Mariatti ◽  
Radziana Ramlee ◽  
Zainal Arifin Mohd Ishak ◽  
Abdul Rahman Mohamed

A hand lay-up and vacuum bagging method was used in this study to fabricate glass fiber/epoxy laminated composites and carbon fiber/epoxy composite laminates with multi-walled carbon nanotube (MWCNT). The density, flexural properties, and burning rate of the laminated composites incorporated with different concentration of MWCNT (0.5, 1.0, and 1.5 vol%) were investigated and analyzed. Trend in the density, flexural and burning rate of glass fiber composite laminates were compared to those of carbon fiber composite laminates. Effect of MWCNT concentration on glass fiber composites properties varies from carbon fiber composite laminates. Incorporation of 0.5vol% of MWCNT has increased flexural strength by 54.4% compared to 5-ply glass fiber composite laminates. Nonetheless addition of 1vol% of MWCNT has only increased flexural strength by 34% compared to 5-ply carbon fiber laminated composites. Incorporation of MWCNT has successfully reduced the burning rate of the glass fiber composites as well as the carbon fiber laminated composites.


Author(s):  
Irina G. Goryacheva ◽  
◽  
Almira R. Meshcheryakova

The model of the frictional interaction of a fiber composite material with a rigid non- wearing body is proposed, which makes it possible to study the effect of the mechanical and strength characteristics of the fiber and matrix materials and the composite structure on its stress state, in particular, at the fiber-matrix interface. Analysis of the stress distribution in the subsurface layers of the composite was carried out for different values of the ratio of matrix to fiber materials hardness, the sliding friction coefficient and the distance between the fibers. For the known failure criteria of fiber composites, the conclusions about the effect of the structure and relative strength properties of a fiber (fiber bundle) and matrix on the pattern of subsurface fracture of the composite under sliding friction conditions are made


Polymers ◽  
2021 ◽  
Vol 13 (14) ◽  
pp. 2264
Author(s):  
Raphael H. M. Reis ◽  
Fabio C. Garcia Filho ◽  
Larissa F. Nunes ◽  
Veronica S. Candido ◽  
Alisson C. R. Silva ◽  
...  

Fibers extracted from Amazonian plants that have traditionally been used by local communities to produce simple items such as ropes, nets, and rugs, are now recognized as promising composite reinforcements. This is the case for guaruman (Ischinosiphon körn) fiber, which was recently found to present potential mechanical and ballistic properties as 30 vol% reinforcement of epoxy composites. To complement these properties, Izod impact tests are now communicated in this brief report for similar composites with up to 30 vol% of guaruman fibers. A substantial increase in impact resistance, with over than 20 times the absorbed energy for the 30 vol% guaruman fiber composite, was obtained in comparison to neat epoxy. These results were statistically validated by Weibull analysis, ANOVA, and Tukey’s test. Scanning electron microscopy analysis disclosed the mechanisms responsible for the impact performance of the guaruman fiber composites.


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