Defect formation during preforming of a bi-axial non-crimp fabric with a pillar stitch pattern

Chen, S.; McGregor, O.P.L.; Harper, L.T.; Endruweit, A.; Warrior, N.A.

doi:10.1016/j.compositesa.2016.09.016

Cited by 64 publications

(80 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Compressive strains along the principal yarns, which are plotted along the two primary yarn directions in Figure 12, were relatively low (for example in comparison to previous reported work [28]). Therefore, mesoscale wrinkling due to yarn buckling (compressive strains) was limited to some minor regions on the top surface of the formed part (green contours), as indicated by the photos.…”

Section: Ddf Defect Formationmentioning

confidence: 86%

“…The in-plane shear behaviour of the FCIM359 fabric has been previously characterised by the authors using the picture frame test [28] and is presented in Figure 4. The force required to shear a fabric specimen of given dimensions was measured as a function of the shear angle.…”

Section: Non-crimp Fabric Characterisationmentioning

confidence: 99%

“…For validation, force-displacement data from the simulation of a picture frame test was shown to be within the bounds of the experimental data (the root mean square error was approximately 5 %). Further validation was conducted for hemisphere forming [28], for which the constitutive relation for the NCF fabric plies was shown to suitably capture the onset of the main defect mechanisms, and local shear angles were predicted within ±5° of the experimental values.…”

Section: Ncf Materials Modelmentioning

confidence: 99%

“…The constitutive model for the NCF plies was previously developed by the authors [28]. A non-orthogonal constitutive relation was employed to define the asymmetric forming behaviour of NCF based on homogenisation.…”

Section: Ncf Materials Modelmentioning

confidence: 99%

“…For forming simulations, each fabric ply was modelled in Abaqus/Explicit using quadrilateral membrane elements (M3D4R), with a maximum edge length of 5 mm, which was found suitable in a mesh sensitivity study presented elsewhere [28]. The diaphragms were modelled using S4 shell elements with dimensions 5 mm × 5 mm, which were constrained in the x-y plane around the perimeter to replicate the constraints on the diaphragm forming rig.…”

Section: Ddf Process Modelmentioning

confidence: 99%

See 4 more Smart Citations

Double diaphragm forming simulation for complex composite structures

Chen

McGregor

Endruweit

et al. 2017

Composites Part A: Applied Science and Manufacturing

Self Cite

View full text Add to dashboard Cite

A finite element (FE) material model has been developed to simulate the double diaphragm forming (DDF) process, to identify potential defects when forming complex 3D preforms from 2D biaxial non-crimp fabric plies. Three different metrics have been introduced to predict and characterise defects, which include local shear angles to determine ply wrinkling induced by over-shear, compressive strains in the primary fibre directions to determine bundle wrinkling, and tensile stresses in the primary fibre directions to determine fabric bridging . The FE simulation is in good agreement with experiments performed on a demonstrator component. Results indicate that fabric bridging occurs in large-curvature regions, which is the dominant defect in DDF. The axial tensile stress in fibres has been used as a measure to identify suitable positions and orientations for darts, to alleviate fabric bridging and improve surface conformity, whilst minimising the effect on the mechanical performance of the component.

show abstract

Section: Ddf Defect Formationmentioning

confidence: 86%

Section: Non-crimp Fabric Characterisationmentioning

confidence: 99%

Section: Ncf Materials Modelmentioning

confidence: 99%

Section: Ncf Materials Modelmentioning

confidence: 99%

Section: Ddf Process Modelmentioning

confidence: 99%

See 3 more Smart Citations

Double diaphragm forming simulation for complex composite structures

Chen

McGregor

Endruweit

et al. 2017

Composites Part A: Applied Science and Manufacturing

Self Cite

View full text Add to dashboard Cite

show abstract

Influence of yarn structure and coating on the mechanical performance of continuous viscose fiber/epoxy composites

et al. 2021

View full text Add to dashboard Cite

The present study investigated the effect of selected structural parameters on the mechanical performance of regenerated cellulose composites. The experimental setup comprised continuous viscose (rayon) yarns embedded in a matrix of epoxy resin. Mechanical and microscopic characterizations involved comparing the following: yarns consisting of untwisted filaments and twisted warp and weft yarns taken from a plain weave fabric, yarns with and without avivage (fiber finish), as well as yarns with and without an acrylic coating. During the epoxy treatment, samples were either prestressed or laid horizontally to preserve the original yarn structure. Tensile tests revealed that yarn crimp had a significant impact on the strength properties of composite specimens, a higher crimp ratio leading to a decrease in performance. Applying prestress to crimped yarns has proven to be an effective way to enable straight alignment in the loading direction, which is essential for the design of stiffness-and strength-optimized yarn composites. Unlike an avivage, which did not markedly affect the mechanical properties of composite yarns, the application of an acrylic coating prior to resin impregnation was found to provide significantly increased extensibility and more ductile fracture behavior.

show abstract

Interlayer interaction characteristics of multi‐layered plain woven glass fabric in hemisphere forming

Mei

Wei

et al. 2022

Polymer Composites

View full text Add to dashboard Cite

Characterizing the interlayer interaction is beneficial to mitigate the manufacturing defects in the multi‐layered fabric forming of composite. However, the interlayer interactions including the force and sliding distance, and their effects on the defect generation have not been reported yet. Here, the monolayer and multi‐layered fabric hemisphere forming were conducted by experiments. Firstly, the forming force and deformation modes at different hemisphere regions are confirmed in the monolayer fabric forming as a reference. Then, in the multi‐layered forming, the interlayer interaction is confirmed to still exist in the configuration with the same ply orientations, whereas the forming force, forming force rate, and interlayer sliding are smaller than that in the configuration with different ply orientations. In addition, with the increase of layer number, the extent of interlayer interaction is improved, which intensifies the defect from the out of plane yarn buckling to the macro wrinkle in the tensile direction. Especially, it is revealed that the tensile direction of lower layer should be avoided under the shear direction of upper layer to reduce the interlayer sliding. These results obtained here provide an important reference to the multi‐layered plain woven fabric forming.

show abstract

Defect formation during preforming of a bi-axial non-crimp fabric with a pillar stitch pattern

Cited by 64 publications

References 23 publications

Double diaphragm forming simulation for complex composite structures

Double diaphragm forming simulation for complex composite structures

Influence of yarn structure and coating on the mechanical performance of continuous viscose fiber/epoxy composites

Interlayer interaction characteristics of multi‐layered plain woven glass fabric in hemisphere forming

Contact Info

Product

Resources

About