Investigation of Resin Pocket Area Effect on Crack Growth in Foam Core of Composite Wind Turbine Blade by the Finite Element Method

Authors

1 MSc Graduate, Department of Mechanical Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran

2 Professor, Department of Mechanical Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran

3 PhD Candidate, Department of Mechanical Engineering, Faculty of Engineering, Ferdowsi University of Mashhad, Mashhad, Iran

Abstract

Resin pocket area is a common defect in manufactruring of sandwich composite using vacuum infusion process (VIP). In this paper, a numerical study is performed on crack growth behavior and failure modes of a sandwich composite wind turbine blade by means of extended finite element method (XFEM) and considering virtual crack closure technique (VCCT). The effect of resin pocket area on crack growth is investigated by considering different sizes for this area. Results of numerical analysis have shown that crack growth in the specimen initiates in foam core under loading nose and propagates through the middle of foam core and decreases its angle and grows towards the tapered area until it reaches to the core-face interface. Calculation of stress intensity factors (SIFs) has shown that first and second fracture modes are dominant modes in crack initiation and propagation steps, respectively. It is also observed that small and average sizes of resin pocket area in sandwich composite specimens delays the damage propagation and large resin pocket area accelerates damage progress. Finally, numerical and experimental results of crack growth path and load-displacement behavior of four-point bending test have shown a good accordance.

Keywords

Main Subjects

References

[1]   Zenkert D (1997) An introduction to sandwich construction. Engineering Materials Advisory Services.
[2]   Chen C, Kam T (2011) Failure analysis of small composite sandwich turbine blade subjected to extreme wind load. Procedia Engineer 14: 1973-1981.
[3]   Kuczma SK, Vizzini AJ (1999) Failure of sandwich to laminate tapered composite structures. AIAA J 37:  227-231.
[4]   Vadakke V, Carlsson LA (2004) Experimental investigation of compression failure of sandwich specimens with face/core debond. Compos Part B-Eng 35: 583-590.
[5]   Steeves CA, Fleck NA (2004) Collapse mechanisms of sandwich beams with composite faces and a foam core loaded in three-point bending. Part II: Experimental investigation and numerical modelling. Int J Mech Sci 46:  585-608.
[6]   Lindberg J (2007) Transition from sandwich to solid skin composites-An investigation of the optimal design. MS. Thesis, KTH School of Engineering Sciences University, KTH Royal Institute of technology.
[7]   Gibson RF (2011) A mechanics of materials/fracture mechanics analysis of core shear failure in foam core composite sandwich beams. J Sandw Struct Mater 13(1): 83-95.
[8] ملکی­نژاد بهابادی ح، رحیمی غ، فرخ آبادی ا (1395) مطالعه عددی و تجربی جدایش رویه از هسته در سازه­های ساندویچی کامپوزیتی با هسته موج­دار ترکیبی تحت بار خمشی. مجله مهندسی مکانیک مدرس 62-52: (6)16.
[9] طاهری بهروز ف، منصوری نیک م (1396) بررسی تجربی و عددی رفتار تیر­های ساندویچی کامپوزیتی تحت خمش چهار نقطه. مجله مهندسی مکانیک مدرس 252-241: (1)17.
[10]    Caliskan U, Apalak MK (2017) Low velosity bending impact behavior of foam core sandwich beams: Experimental. Compos Part B-Eng 112: 158-175.
[11]  راستگو ع، بهاءلو هوره ح (مترجمین)، (1389) آزمون و تحلیل خستگی (نظریه و کاربرد)، چاپ اول، انتشارات دانشگاه تهران، صفحه 321.
[12]    Noury P, Shenoi R, Sinclair I (1998) On mixed-mode fracture of pvc foam. international journal of fracture 92: 131-151.
[13]    ABAQUS (2014) ABAQUS Documentation Dassault Systems, Providence, RI, USA.
[14]    Zamani P, Jaamialahmadi A, Shariati M (2016) Ductile failure and safety optimization of gas pipeline. Journal of Solid Mechanics 8(4): 744-755.
[15]    Mohammadi S (2008) Extended finite element method: For fracture analysis of structures. John Wiley & Sons.
[16]    Data Sheet, Airex Baltek Banova, Airex C70 Universal Structural Foam, Baltec Inc., USA.
[17]    Viana GA, Carlsson LA, (2002) Mechanical properties and fracture characterization of cross-linked PVC foams. J Sandw Struct Mater 4: 99-113.
[18]    Aviles F (2005) Local buckling and debond propagation in sandwich columns and panels. Ph.D Dissertation, Department of Mechanical Engineering, Florida Atlantic University.
[19]  فرجادفر ر، حسینی ف (اردیبهشت 1395) آزمون خواص مکانیکی کامپوزیت­های گلس/اپوکسی با الیاف سه جهته. اسناد پژوهشکده هوا-خورشید، دانشگاه فردوسی مشهد، مشهد، ایران.
[20]    Saenz EE, Carlsson L.A. Karlsson A. (2011) Characterization Of Fracture Toughness G (Sub c) of PVC and PES foams. J Mater Sci 46(9): 3207-3215.
[21]    Poapongsakorn P, Carlsson LA (2013) Fracture toughness of closed-cell PVC foam: Effects of loading configuration and cell size. Compos Struct 102: 1-8.
[22]    Soni SM, Gibson RF, Ayorinde EO (2009) The influence of subzero temperatures on fatigue behavior of composite sandwich structures. Compos Sci Technol 69: 829-838.
[23]   ASTM C393-06 (2006) Standard test method for core sear properties of sandwich constructions by beam flexure.
Journal of Solid and Fluid Mechanics
Volume 8, Issue 4
January 2019
Pages 27-38

Files

Share

How to cite

Statistics