TY - JOUR
T1 - Mechanisms of origin and classification of out-of-plane fiber waviness in composite materials — A review
AU - Thor, Michael
AU - Sause, Markus G.R.
AU - Hinterhölzl, Roland M.
N1 - Funding Information:
Funding: The Austrian Research Promotion Agency (FFG) is gratefully acknowledged for funding this research in the BRIDGE 1 program (Project FiberWave; Grant No. 855711) and the TakeOff program (Project BeyondInspection; Grant No. 874540).
Publisher Copyright:
© 2020 by the authors. Licensee MDPI, Basel, Switzerland.
PY - 2020
Y1 - 2020
N2 - 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.
AB - 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.
KW - Composite materials
KW - Fiber waviness
KW - Manufacturing effects
KW - Review
KW - Wrinkling
UR - http://www.scopus.com/inward/record.url?scp=85100382114&partnerID=8YFLogxK
U2 - 10.3390/jcs4030130
DO - 10.3390/jcs4030130
M3 - Review article
AN - SCOPUS:85100382114
SN - 2504-477X
VL - 4
JO - Journal of Composites Science
JF - Journal of Composites Science
IS - 3
M1 - 130
ER -