scholarly journals An Experimental Study of the Cyclic Compression after Impact Behavior of CFRP Composites

2021 ◽  
Vol 5 (11) ◽  
pp. 296
Author(s):  
Raffael Bogenfeld ◽  
Christopher Gorsky
Keyword(s):  
Composite Laminates ◽  
Composite Structures ◽  
Impact Behavior ◽  
Damage Growth ◽  
Compression Load ◽  
Kink Bands ◽  
Cyclic Compression ◽  
Compression After Impact ◽  
Ultimate Failure ◽  
Damage Tolerant

The behavior of impact damaged composite laminates under cyclic load is crucial to achieve a damage tolerant design of composite structures. A sufficient residual strength has to be ensured throughout the entire structural service life. In this study, a set of 27 impacted coupon specimens is subjected to quasi-static and cyclic compression load. After long intervals without detectable damage growth, the specimens fail through the sudden lateral propagation of delamination and fiber kink bands within few load cycles. Ultrasonic inspections were used to reveal the damage size after certain cycle intervals. Through continuous dent depth measurements during the cyclic tests, the evolution of the dent visibility was monitored. These measurements revealed a relaxation of the indentation of up to 90% before ultimate failure occurs. Due to the distinct relaxation and the short growth interval before ultimate failure, this study confirms the no-growth design approach as the preferred method to account for the damage tolerance of stiffened, compression-loaded composite laminates.

Unfolding the effects of tuft density on compression after impact properties in unidirectional carbon/epoxy composite laminates

2021 ◽  
Vol 258 ◽  
pp. 113378
Author(s):  
Kundan K. Verma ◽  
C.H. Viswarupachari ◽  
Kotresh M. Gaddikeri ◽  
S. Ramesh ◽  
S. Kumar ◽  
...  
Keyword(s):  
Composite Laminates ◽  
Epoxy Composite ◽  
Impact Properties ◽  
Compression After Impact

scholarly journals Improvement of the Impact Properties of Composite Laminates by Means of Nano-Modification of the Matrix—A Review

2018 ◽  
Vol 8 (12) ◽  
pp. 2406 ◽  
Author(s):  
Hamed Saghafi ◽  
Mohamad Fotouhi ◽  
Giangiacomo Minak
Keyword(s):  
Composite Laminates ◽  
Cost Effective ◽  
Careful Consideration ◽  
Impact Performance ◽  
Compression After Impact ◽  
The Matrix ◽  
The Right ◽  
2D And 3D ◽  
The Impact ◽  
Selection Of

This paper reviews recent works on the application of nanofibers and nanoparticle reinforcements to enhance the interlaminar fracture toughness, to reduce the impact induced damage and to improve the compression after impact performance of fiber reinforced composites with brittle thermosetting resins. The nanofibers have been mainly used as mats embedded between plies of laminated composites, whereas the nanoparticles have been used in 0D, 1D, 2D, and 3D dimensional patterns to reinforce the matrix and consequently the composite. The reinforcement mechanisms are presented, and a comparison is done between the different papers in the literature. This review shows that in order to have an efficient reinforcement effect, careful consideration is required in the manufacturing, materials selection and reinforcement content and percentage. The selection of the right parameters can provide a tough and impact resistant composite with cost effective reinforcements.

Experimental investigation of composite laminates subject to low-velocity edge-on impact and compression after impact

2018 ◽  
Vol 186 ◽  
pp. 335-346 ◽  
Author(s):  
Solver I. Thorsson ◽  
Sunil P. Sringeri ◽  
Anthony M. Waas ◽  
Brian P. Justusson ◽  
Mostafa Rassaian
Keyword(s):  
Experimental Investigation ◽  
Composite Laminates ◽  
Low Velocity ◽  
Compression After Impact

Preparation and Characterization of Structural Damping Composites Toughened by Polyamide Nonwoven Fabrics

2016 ◽  
Vol 848 ◽  
pp. 189-195
Author(s):  
Nan Nan Ni ◽  
Yue Fang Wen ◽  
De Long He ◽  
Miao Cai Guo ◽  
Xiao Su Yi
Keyword(s):  
Shear Strength ◽  
Composite Laminates ◽  
Impact Resistance ◽  
Nonwoven Fabric ◽  
Mechanical Analysis ◽  
Interlaminar Shear Strength ◽  
Structural Damping ◽  
Nonwoven Fabrics ◽  
Compression After Impact ◽  
Interlaminar Shear

A new kind of structural damping composites was prepared by interleaving polyamide nonwoven fabrics (PNF) between the carbon fiber reinforced epoxy composite laminates. The damping behaviors of the composites made were experimentally investigated using cantilever beam test and dynamic mechanical analysis. The damping ratios of the nonwoven fabrics interleaved composites were compared with the ones of non-interleaved composites. In addition, the interlaminar shear strength and flexible modulus of the composites were also investigated, as well as the composite compression after impact (CAI), Mode I and Mode II interlaminar fracture toughness (GIC and GIIC), in order to evaluate the influence of the polyamide nonwoven fabric layers on the composite mechanical properties. It has been observed that the interleaved polyamide nonwoven fabric layers greatly improved the composite damping loss factors, and the composites containing 7 layers of PNF showed the best damping behavior. Meanwhile, the addition of PNF showed a negligible influence on the composite flexible strength and modulus and interlaminar shear strength. Most importantly, the CAI, GIC and GIIC tests indicated that the composite interlaminar toughness and impact resistance were significantly improved by the interleaved PNF. Finally, the reinforcing mechanism of this kind of composites is discussed.

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