A numerical method to evaluate the material properties degradation in composite RVEs due to fiber-matrix debonding and induced matrix cracking

Naghdinasab, Mohsen; Farrokhabadi, Amin; Madadi, Hamidreza

doi:10.1016/j.finel.2018.04.008

Cited by 43 publications

(15 citation statements)

References 41 publications

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“…It can be seen that the gap can create a resin-pocket with a dimension of a hundred microns to a millimeter. Thus, the current theoretical and numerical micromechanical models [28][29][30] are not capable of performing the homogenization on the defective areas for multiscale damage analysis of the composite structure. On the other hand, the current FE approaches use FE packages with built-in damage models.…”

Section: Induced Defect Layer Methodsmentioning

confidence: 99%

Induced defect layer method to characterize the effect of fiber tow gaps for the laminates manufactured by automated fiber placement technique

Ghayour

Hojjati

Ganesan

2021

Journal of Composite Materials

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Automated manufacturing defects are new types of composite structure defects induced during fiber deposition by robots. Fiber tow gap is one of the most probable types of defects observed in the Automated Fiber Placement (AFP) technique. This defect can affect the structural integrity of structures by reducing structural strength and stiffness. The effect of this defect on the mechanical response of the composite laminates has been investigated experimentally in the literature. However, there is still no efficient numerical/analytical method for damage assessment of composite structures with distributed induced gaps manufactured by the AFP technique. The present paper aims to develop the Induced Defect Layer Method (IDLM), a new robust meso-macro model for damage analysis of the composite laminates with gaps. In this method, a geometrical parameter, Gap Percentage (GP), is implemented to incorporate the effect of induced-gaps in the elastic, inelastic, and softening behavior at the material points. Thus, while the plasticity and failure of the resin pockets in conjunction with intralaminar composite damages can be evaluated by this method, the defective areas are not required to be defined as resin elements in the Finite Element (FE) models. It can also be applied for any arbitrary distributions of the defects in the multi-layer composite structures, making it a powerful tool for continuum damage analysis of large composite structures. Results indicate that the proposed method can consider the effect of gaps in both elastic and inelastic behavior of the composite laminate with defects. It also provides good agreement with the experimental results.

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Section: Induced Defect Layer Methodsmentioning

confidence: 99%

Induced defect layer method to characterize the effect of fiber tow gaps for the laminates manufactured by automated fiber placement technique

Ghayour

Hojjati

Ganesan

2021

Journal of Composite Materials

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“…Therefore, the representative volume element (RVE) is applied in calculation to save calculation cost. [28][29][30] The material constant of helical composite spring can be obtained by combining the stiffness matrix of skin structure and core structure.…”

Section: Finite Element Analysis 241 | Analysis Methods Of Helical Composite Springmentioning

confidence: 99%

Composite helical spring with skin‐core structure: Structural design and compression property evaluation

et al. 2020

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The helical spring is an essential mechanical component of automobile and machinery and has been widely used in industrial application. The weight reduction is the requirement of current material design and also the research trend for material development. In this study, a novel composite helical spring with "skin-core" structure was designed and fabricated with an integrated formation process based on the vacuum-assisted resin infusion technology. Based on the different function of skin and core, the skin structure was weft knitting tube made of aramid and ultra-high molecular weight polyethylene fiber, and the core structure was unidirectional carbon fiber. By selecting material for knitting tube and adjusting the volume content of carbon fiber core, the static and fatigue compression properties of composite helical spring were investigated. It has been found that the spring torsion and bending performance can be improved by wrapping the core with the knitting tube as the spring wire. Moreover, the finite element method was applied to further analyze the stress evolution of the "skin-core" composite helical spring during compression and fatigue. The results of compression test and simulation show that the spring stiffness can be effectively improved by using knitting tube and increasing the content of carbon fiber. The stress of the spring cross section is concentrated in the internal radial region of 180 , and the distribution of the corresponding cross sections is relatively uniform. The "skin-core" structure with aramid knitting tube as the outer skin and carbon fiber as the spring core significantly improves the load-carrying capacity and stability of the composite spring. The proposed lightweight helical composite could provide a replacement strategy of existing metal or unidirectional filament reinforced springs used in the engineering applications.

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“…The main purpose of the present study is to examine the strength capability of 90° layers in cross‐ply laminates, which is a critical parameter to delay the formation of induced delamination in the next loading steps. Among the dominant damage modes at the scale of the constituents in 90° layers, fiber–matrix debonding and matrix microcracking are the most significant ones 4 . As a result of the coalescence of these damage modes, transverse matrix cracking and induced delamination appear 5 .…”

Section: Introductionmentioning

confidence: 99%

In situ strength analysis of cross‐ply composite laminates containing defects and interleaved woven layer using a computational micromechanics approach

Rafie

Madadi

Farrokhabadi

et al. 2021

Fatigue Fract Eng Mat Struct

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The transverse strength of 90° plies located in cross‐ply laminates subjected to transverse tension is investigated numerically. To reach this aim, it is assumed that the transverse cracking is formed by coalescence of fiber–matrix debonding, which propagates along the planes parallel to the fibers. The two‐dimensional finite element model (FEM) investigates the dominant micromechanical damage mechanisms, fiber–matrix debonding, and matrix cracking using the cohesive zone model (CZM) and plasticity, respectively. The numerical simulation is according to the extended computational micromechanics (ECMM) approach, which can be applied as a useful virtual test method instead of performing costly characterization tests. The results obtained from the present study show that the defects such as voids, imperfections, and residual stresses contribute to reducing the in situ strength of 90° plies. In the case of using an interleaved woven layer, the formation of the first transverse crack in unit cells within 90° layer is delayed.

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A numerical method to evaluate the material properties degradation in composite RVEs due to fiber-matrix debonding and induced matrix cracking

Cited by 43 publications

References 41 publications

Induced defect layer method to characterize the effect of fiber tow gaps for the laminates manufactured by automated fiber placement technique

Induced defect layer method to characterize the effect of fiber tow gaps for the laminates manufactured by automated fiber placement technique

Composite helical spring with skin‐core structure: Structural design and compression property evaluation

In situ strength analysis of cross‐ply composite laminates containing defects and interleaved woven layer using a computational micromechanics approach

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