Effective moduli and failure considerations for composites with periodic fiber waviness

Karami, G.; Garnich, Mark R.

doi:10.1016/j.compstruct.2004.02.005

Cited by 82 publications

(53 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Hsiao and Daniel [11] explored the relation between fiber waviness and mechanical properties, and proposed a theoretical model of elastic constants on a unidirectional carbon/epoxy composite with fiber waviness by the assumption of sine function. The shape of waviness by sine function was also developed by numerical analysis method [12,13]. The results show that the ratio of amplitudes denoted as waviness parameter has an effect on the mechanical properties.…”

Section: Introductionmentioning

confidence: 97%

“…Allison and Evans [14] inserted a single waviness part in a unidirectional composite and discussed its strength by identifying its wavy shape as a notch. Karami and Garnich [12] applied a failure criterion to a laminate in which a fiber wavy layer is included, using a finite element analysis. As a key-point in these papers, the fiber wavy shape was all given as a sinusoid [15].…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Effect of Fiber Waviness on Tensile Properties of Sliver-Based Natural Fiber Composites

Piyatuchsananon¹,

Ren²,

Goda³

2018

Natural and Artificial Fiber-Reinforced Composites as Renewable Sources

View full text Add to dashboard Cite

Glass and carbon fiber-reinforced composite materials have been applied for the high demand in industrial use to date, because their advantages are light weight, high strength, and corrosion resistance. However, the disposal problem after the use of these materials has also surfaced as a serious environmental problem. As a measure to solve this problem, many researchers have tried to investigate the potential of plant-based natural fibers instead of artificial fibers. When we use natural fibers as a long fiberreinforcement, the negative point is irregular fiber waviness inherent in a sliver form. This is because such fiber waviness often decreases the mechanical properties. The purpose of this study is thus to clarify the relation between irregular fiber waviness and the composite's tensile strength. The clarification was performed from two points of view: One is quantification of irregular fiber waviness, based on spatial analysis such as Local Moran's I and Geary's c. Result shows that quantified parameters were correlated well with tensile strengths of sliver-based natural fiber composites. Another is a 3-D finite element analysis in which the fiber waviness was treated as an orthotropic body. Finally, the relation of the tensile strengths with maximum stress and Tsai-Hill criterions was discussed.

show abstract

Section: Introductionmentioning

confidence: 97%

Section: Introductionmentioning

confidence: 99%

Effect of Fiber Waviness on Tensile Properties of Sliver-Based Natural Fiber Composites

Piyatuchsananon¹,

Ren²,

Goda³

2018

Natural and Artificial Fiber-Reinforced Composites as Renewable Sources

View full text Add to dashboard Cite

show abstract

“…Bloom et al (2013) reported up to 40 % reduction in tensile strength due to localized wrinkles in glass/ epoxy composites. Garnich and Karami (2005), on the other hand, reported that wrinkling can lead to a decrease of as much as 80 % in the longitudinal modulus of elasticity along the expected direction of the fibers. Allison et al (2012) observed a 37 % reduction in flexural strength of uniaxial S-glass/epoxy composites caused by localized wrinkling.…”

Section: Adverse Effects Of Fiber Undulation On Mechanical Propertiesmentioning

confidence: 99%

“…Given the distribution of misalignment angles within a graphite/epoxy composite, the model predicts effective axial shear modulus, transverse Young's modulus, as well as axial Young's modulus. Other authors (Fedulov et al, 2015;Karami and Garnich, 2005;Li et al, 2016;Mukhopadhyay et al, 2015) used finite element micromechanical models for fibrous materials to pre-Intern. Polymer Processing XXXII (2017) 5 Li et al (2016) used a continuum mechanical model based on microsphere approach to predict the mechanical properties of unidirectional composites using the distribution of fiber misalignment.…”

Section: Adverse Effects Of Fiber Misalignment On Mechanical Propertiesmentioning

confidence: 99%

See 1 more Smart Citation

Process Induced Defects in Liquid Molding Processes of Composites

Hamidi

Altan

2017

International Polymer Processing

View full text Add to dashboard Cite

Liquid Composite Molding (LCM) processes are cost efficient manufacturing alternatives to traditional autoclave technology for producing near-net shape structural composite parts. However, process induced defects often limit wider usage of LCM in structural applications. Thorough knowledge of these defects, as well as their formation mechanisms and prevention techniques, is essential in developing improved LCM processes. In this article, process induced defects in liquid molding processes of composites, categorized into preform, flow induced and cure induced defects, are reviewed. Preform defects are further presented as fiber misalignment and fiber undulation (waviness and wrinkling). The respective causes, detrimental effects, and possible prevention methods of these defects are presented. Thereafter, flow induced defects are classified as voids and dry spots. Dry spot formation mechanisms in LCM processes and available prevention techniques are summarized. In addition, void formation mechanisms, adverse effects on composite properties, and removal techniques are presented. Cure induced defects include microcracks, void growth and geometrical distortions (warpage and spring-in). Each of these defects are discussed along with their underlying causes as well as their control and reduction schemes.

show abstract

Micromechanical Modeling of Heterogeneous Materials at Finite Strain

Abadi

2012

Wiley Encyclopedia of Composites

View full text Add to dashboard Cite

A micromechanical modeling procedure is presented to predict the effective mechanical properties of heterogeneous materials at finite strain. A repeating unit cell (RUC) is assumed to represent the microstructure of the heterogeneous materials. The response of RUC is evaluated for different equivalent macroscopic deformation fields considering the periodicity conditions on the deformation of RUC boundary surfaces. Volume averaging scheme is implemented to apply the local macroscopic deformation gradient tensor to the RUC assigned to the microstructure. On the basis of the energy balance, the local nominal stress tensor is determined as a function of the resultant forces applied on the boundary surfaces of RUC and initial surface area. A computational technique is subsequently developed to obtain the response of heterogeneous microstructures. To demonstrate the details of micromechanical technique, it is implemented to evaluate the response of heterogeneous materials such as elastomeric composites and metal matrix composites with different microstructures subjected to the axial, shear, and combined loadings. The performance is successfully verified by comparison of the deformation in the macroscopic level to the response of a homogenized cell. This micromechanics tool provides a powerful viable algorithm for the determination of nonlinear properties in continuum mechanics material characterization at finite strain.

show abstract

Effective moduli and failure considerations for composites with periodic fiber waviness

Cited by 82 publications

References 23 publications

Effect of Fiber Waviness on Tensile Properties of Sliver-Based Natural Fiber Composites

Effect of Fiber Waviness on Tensile Properties of Sliver-Based Natural Fiber Composites

Process Induced Defects in Liquid Molding Processes of Composites

Micromechanical Modeling of Heterogeneous Materials at Finite Strain

Contact Info

Product

Resources

About