Tensile failure of laminates containing an embedded wrinkle; numerical and experimental study

Mukhopadhyay, Supratik; Jones, Mike I; Hallett, Stephen R.

doi:10.1016/j.compositesa.2015.07.007

Cited by 81 publications

(78 citation statements)

References 22 publications

(38 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…It is worth mentioning that failure was observed to be localized in the region of the undulation (Adams and Hyer, 1993;Mukhopadhyay et al, 2015). Furthermore, failure mechanisms are reported to depend on wrinkle severity as well.…”

Section: Adverse Effects Of Fiber Undulation On Mechanical Propertiesmentioning

confidence: 99%

“…Cure induced defects refer to composites' internal flaws formed during curing. All three defect types typically act as sites of potential failure initiation and reduce the load bearing capacity (Anders et al, 2016;Hagstrand et al, 2005;Mukhopadhyay et al, 2015). Therefore, understanding the formation mechanisms of such defects is essential towards developing improved LCM processes.…”

Section: Special Issue Contributions -Review Articlementioning

confidence: 99%

“…Depending on the manufacturing process, other types of defects can prove to be much more difficult to eliminate. LCM processes are associated with a number of specific manufacturing defects such as voids, dry spots, in-and out-of-plane fiber undulations, microcracks and part distortions (Fedulov et al, 2015;Hagstrand et al, 2005;Hamidi and Altan, 2017;Mukhopadhyay et al, 2015;Anders et al, 2016). As depicted in Fig.…”

Section: Defect Types In Lcmmentioning

confidence: 99%

“…2, the geometry of a typical undulation is described by the ratio of the amplitude, d, to the wavelength, k, of the undulation. The severity of both the waviness and wrinkling are commonly characterized by the magnitude of d/k which is referred to as the amplitude-to-wavelength ratio (Altmann et al, 2015;Mukhopadhyay et al, 2015;Wang et al, 2013). These preform defects in composite parts are subject to various parameters influencing the fabrication processes.…”

Section: Preform Defects In Lcmmentioning

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 4 more Smart Citations

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

Section: Adverse Effects Of Fiber Undulation On Mechanical Propertiesmentioning

confidence: 99%

Section: Special Issue Contributions -Review Articlementioning

confidence: 99%

Section: Defect Types In Lcmmentioning

confidence: 99%

Section: Preform Defects In Lcmmentioning

confidence: 99%

Section: Adverse Effects Of Fiber Misalignment On Mechanical Propertiesmentioning

confidence: 99%

See 3 more Smart Citations

Process Induced Defects in Liquid Molding Processes of Composites

Hamidi

Altan

2017

International Polymer Processing

View full text Add to dashboard Cite

show abstract

Experimental and numerical investigation on flexural performance of carbon fiber reinforced polymer composites with uniform and non‐uniform waviness

2022

View full text Add to dashboard Cite

The failure of unidirectional and quasi‐isotropic carbon fiber reinforced polymer composite laminate with uniform and non‐uniform out‐of‐plane waviness defects were examined. Experimental tests and numerical simulations were performed for specimens with and without defects. Specimens with different types of waviness such as uniform embedded, non‐uniform hump and non‐uniform indentation were fabricated for testing their performance under three‐point flexural tests. Optical microscopic images were captured throughout the test to investigate the initiation and progression of failure in laminates. Three‐dimensional finite element (FE) models were built by considering actual specimen and defect geometric configurations obtained from optical microscopy. User material subroutine (UMAT) was developed and implemented in Abaqus/Standard to simulate intra‐ply failures as a continuum damage mechanism. The generated models are used to recognize damage initiation and progression during the flexural test. The experimental observations and FE simulation results are in good agreement for failure loads and damage mechanisms for different waviness cases.

show abstract

Compression and interlaminar shear behavior of steered laminates manufactured by automated fiber placement

Zheng,

Tang,

et al. 2024

Polymer Composites

View full text Add to dashboard Cite

Variable stiffness (VS) composite structures can significantly reduce weight by adjusting fiber orientation. However, in current designs, the directional properties of composites cannot be fully utilized due to the lack of comprehensive mechanical characterization of VS laminates. This paper aims to investigate the compressive and out‐of‐plane bending behavior of steered laminates. Firstly, the critical steering radius theory was studied and derived. Secondly, five steered laminates with different radii and one “baseline” laminate were designed, manufactured, and tested to examine the effects of fiber steering on compressive and interlaminar shear strength (ILSS). The results indicate that, compared to the “baseline” laminate, the steered laminates exhibit a decreasing trend in both compressive strength and ILSS, with the maximum reductions being 32.1% in compressive strength and 9% in shear strength. Meanwhile, the microstructure was observed to gain an in‐depth understanding of the changes in the mechanical properties of the steered laminates. This study comprehensively evaluates the mechanical performance of steered laminates and provides appropriate steering limits for the design and manufacture of VS structures.Highlights The critical steering radius theory was studied and derived. Five steered laminates with different radii and one “baseline” laminate were designed, manufactured, and tested to examine the effects of fiber steering on compressive and ILSS. The microstructure was observed to gain an in‐depth understanding of the changes in the mechanical properties of the steered laminates.

show abstract

Tensile failure of laminates containing an embedded wrinkle; numerical and experimental study

Cited by 81 publications

References 22 publications

Process Induced Defects in Liquid Molding Processes of Composites

Process Induced Defects in Liquid Molding Processes of Composites

Experimental and numerical investigation on flexural performance of carbon fiber reinforced polymer composites with uniform and non‐uniform waviness

Compression and interlaminar shear behavior of steered laminates manufactured by automated fiber placement

Contact Info

Product

Resources

About