Consolidation-Driven Defect Generation in Thick Composite Parts

Belnoue, Jonathan P.-H.; Nixon-Pearson, Oliver J.; Thompson, Adam J.; Ivanov, Dmitry; Potter, Kevin D; Hallett, Stephen R.

doi:10.1115/1.4039555

Cited by 83 publications

(72 citation statements)

References 53 publications

(73 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Both Belnoue et al and Sjölander indicate that squeeze flow effects may appear when forming curved geometries. The squeeze flow observed in the fiber direction perpendicular to the forming direction was, in Ref.…”

Section: Methodsmentioning

confidence: 99%

“…Thermoset prepregs compaction limit is often reached at high temperature and pressure levels. Belnoue et al performed a study on compaction of uncured prepreg and used squeeze flow and resin bleed out flow as mechanisms in the modeling work. This experimental work showed the existence of flow transition mechanisms between squeezing and bleeding flows.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Fast forming of multistacked UD prepreg using a high‐pressure process

et al. 2019

View full text Add to dashboard Cite

In this article, the opportunities of fast forming of multistacked UD prepreg when using high-pressure forming were examined in an experimental study. Forming is often considered a bottleneck in manufacturing of composite aircraft parts and speeding up the process is, therefore, of great interest. A Quintus Flexform fluid cell press was used to create pressure of 100 to 400 bars. In the study, different lay-up sequences and thicknesses were tested for manufacturing of c-shaped coupons. Tests were performed at different temperatures and some of the samples were sandwiched with mild steel sheets referred to as a steel sheet dummy. A case study was also performed on a double-curved spar geometry. It was found that forming at a relatively high overall pressure level combined with an elevated temperature, created squeeze flow-related wrinkle formations, and radius thinning. With high pressure forming, material compression/compaction mechanisms showed to have great influence on the forming result. This differs to low pressure vacuum forming, where intraply shear, interply shear, and ply bending are the dominant forming mechanisms. The steel sheet dummy minimized the squeeze flow related wrinkle in the web and flanges. Instead the forming temperature was found to exert the greatest influence on radius thinning. When forming at room temperature, radius thinning was almost eliminated and instead bending-related wrinkles in the flange below the radii appeared. POLYM. COMPOS., 40:3550-3561, 2019.

show abstract

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Fast forming of multistacked UD prepreg using a high‐pressure process

et al. 2019

View full text Add to dashboard Cite

show abstract

“…[5,6,15]) were mainly concerned with prediction and experimental evaluation of the final shape of the specimen, especially corner parts, and were able to detect the effect of layup on the shape or the effect of processing conditions on thickness of flat laminates. The latest research [3,16,17] has shown that more advanced models can predict geometry of complex shape specimens.…”

Section: This Paper Employs the Hyper-viscoelastic Consolidation Modementioning

confidence: 99%

A numerical study of variability in the manufacturing process of thick composite parts

Matveev

Belnoue

Nixon-Pearson

et al. 2019

Composite Structures

View full text Add to dashboard Cite

Consolidation of a prepreg layup to a target thickness is critical in order to achieve the required fibre volume fraction and dimensions in a composite part. Experiments show that different processing conditions lead to different levels of compaction and variability in the thickness.This paper presents an analysis of processing conditions and their effects on consolidation of thick composite components. A model that accounts for both percolation and squeezing flow is employed to study two toughened prepreg systems -IM7/8552 and IMA/M21. This paper analyses the significance of the process parameters on the thickness of prepregs and its variability. The analysis of different layups and processing conditions suggests several strategies to control target thickness and its variability. The IMA/M21 prepreg system was found to have lower variability due to its toughening mechanism. The presented results provide a better understanding of the composite manufacturing and can be used to provide an informed choice in design for manufacture of composite structures.

show abstract

“…Additionally, Kugler and Moon [90] have shown the significant influence of the cooling rate and length. The prediction of instabilities originating from the differences in CTE is very complex, as shown in the studies of Dodwell et al [18] and Belnoue et al [91].…”

Section: Cte Mismatchmentioning

confidence: 99%

“…The strength reductions are associated with out of plane stresses and resulting delamination emanating from the cut ply ends and the small resin-rich zones at the ends of the terminated plies. Belnoue et al [91] investigated the wrinkle formation in tapered laminates under double-sided rigid tooling due to variabilities in the ply thickness, which would lead to a mismatch between mold and preform. The thickness variation of the laminate upon consolidation is responsible for the generation of excess length.…”

Section: Ply Drops In Tapered Laminatesmentioning

confidence: 99%

Mechanisms of Origin and Classification of Out-of-Plane Fiber Waviness in Composite Materials—A Review

2020

View full text Add to dashboard Cite

Out-of-plane fiber waviness, also referred to as wrinkling, is considered one of the most significant effects that occur in composite materials. It significantly affects mechanical properties, such as stiffness, strength and fatigue and; therefore, dramatically reduces the load-carrying capacity of the material. Fiber waviness is inherent to various manufacturing processes of fiber-reinforced composite parts. They cannot be completely avoided and thus have to be tolerated and considered as an integral part of the structure. Because of this influenceable but in many cases unavoidable nature of fiber waviness, it might be more appropriate to consider fiber waviness as effects or features rather than defects. Hence, it is important to understand the impact of different process parameters on the formation of fiber waviness in order to reduce or, in the best case, completely avoid them as early as possible in the product and process development phases. Mostly depending on the chosen geometry of the part and the specific manufacturing process used, different types of fiber waviness result. In this study, various types of waviness are investigated and a classification scheme is developed for categorization purposes. Numerous mechanisms of wrinkling were analyzed, leading to several recommendations to prevent wrinkle formation, not only during composite processing, but also at an earlier design stage, where generally several influence factors are defined.

show abstract

Consolidation-Driven Defect Generation in Thick Composite Parts

Cited by 83 publications

References 53 publications

Fast forming of multistacked UD prepreg using a high‐pressure process

Fast forming of multistacked UD prepreg using a high‐pressure process

A numerical study of variability in the manufacturing process of thick composite parts

Mechanisms of Origin and Classification of Out-of-Plane Fiber Waviness in Composite Materials—A Review

Contact Info

Product

Resources

About