Wyniki wyszukiwania - BazTech

1

Experimental Determination of the Mode I Fracture Toughness in FRP Laminates with Hybrid Delamination Interfaces

Rzeczkowski Jakub, Samborski Sylwester, Prokopek Katarzyna

Advances in Science and Technology. Research Journal

|

2022

|

Vol. 16, no 5

129--135

EN

This paper aims at experimental research of the effect of hybrid interface (carbon/glass fibers) on delamination resistance in unidirectional fiber reinforced polymer (FRP) composite laminates under the mode I opening load conditions. Three group of laminates exhibiting different combinations of reinforcing materials at delamination plane were tested. Critical strain energy release rates were determined by using the double cantilever beam (DCB) tests in accordance with the ASTM D5528 Standard. Values of the GIC were calculated by using classical data reduction schemes and they were compared with values obtained by using an alternative compliance based beam method (CBBM). For precise detection of delamination onset all tests were additionally supported by registration of the acoustic emission (AE) signal. Contribution of mixed-modes were evaluated by using numerical finite element analysis. Obtained outcomes revealed, that differences in the mode I c-SERR values obtained by using four different methods were insignificant. Moreover, the greatest value of the GIC was determined for laminates with hybrid interface and it was equal 0.24 N/mm.

2

Processing and characterization of cathodic dip coated metal/composite-laminates

Gerstenberger C., Osiecki T., Kroll L., Scholz P., Seidlitz H.

Archives of Civil and Mechanical Engineering

|

2016

|

Vol. 16, no. 3

467--472

EN

The current trend shows an increasing demand for novel technologies, that facilitate a functional integration of fiber reinforced polymers (FRP) in metal based structures, especially in automotive industry. To comply with the requirements of large-scale production the use of fiber reinforced thermoplastics in form of hybrid metal/composite-laminates seems advantageous. By targeted exploitation of their high lightweight potential, combined with suitable capabilities for mass production and good damping properties, cost-effective and weight-optimized parts with high stiffness and load capacity can be provided for future applications. As there is little known about the processing and the mechanical properties of thermoplastic based FRP/metal-laminates, the study focuses on the development of novel hybrid laminates with low residual stresses, made of metallic steel sheets and continuous glass or carbon fiber reinforced polyamide 6. In this context, the influence of several pre-operations like sand blasting, cleaning or primer application on the interlaminar shear strength (ILSS) was examined in addition to their resistance to cathodic dip paint treatment.

3

Evolutionary optimization and identification of hybrid laminates

Beluch W., Burczyński T., Kuś W.

Prace Naukowe Politechniki Warszawskiej. Elektronika

|

2006

|

z. 156

39-47

EN

The paper deals with the optimization and identification of hybrid fibre-reinforced laminates. Two tasks are considered: i) the ply orientations optimization, ii) the material constants identification. Different optimization and identification criteria connected with the modal analysis are considered. The evolutionary algorithm is used as the optimization and identification method. In order to accelerate the calculations, the distributed version of the evolutionary algorithm is employed. Finite element method software is used to solve the direct problem for the laminates. Numerical examples of optimization and identification are attached.

4

Wpływ absorpcji wody na właściwości laminatów winyloestrowych wzmocnionych włóknem aramidowym i szklanym

Imielińska K., Wojtyra R.

Kompozyty

|

2003

|

R. 3, nr 7

192-197

PL

Zbadano zachowanie dwóch laminatów o osnowie winyloestrowej, wzmocnionych włóknami aramidowymi i szklanymi w stanie suchym i po zanurzeniu w wodzie. Materiały poddawane są badaniom ze względu na potencjalne zastosowanie w okrętownictwie i brak podobnych danych w literaturze. Wzmocnienie laminatów miało postać tkaniny hybrydowej aramidowo-szklanej (1) lub składało się z na przemian ułożonych jednorodnych warstw włókien aramidowych (Tworon) i szklanych (2). Zbadano chłonność wody do nasycenia (70°C), określając współczynniki dyfuzji wody, zgodnie z II prawem Ficka. Określono właściwości laminatów w próbie zginania i ścinania międzywarstwowego. Laminaty (1) chłoną wodę znacznie wolniej niż laminaty (2) i nasycają się przy wyższej zawartości wody pomimo nieznacznie tylko wyższej zawartości higroskopijnych włókien aramidowych. Wytrzymałość na zginanie i ścinanie międzywarstwowe, jak i moduł sprężystości przy zginaniu są wyższe dla laminatu wzmocnionego tkaniną hybrydową. Dotyczy to zarówno stanu suchego, jak i nasycenia wodą. Woda zaabsorbowana przez laminat wywołuje widoczną degradację mikrostruktury, objawiającą się licznymi pęknięciami na granicy włókien i żywicy. Defekty te nie wywołują obniżenia wytrzymałości na ścinanie międzywarstwowe, ale znacząco zmniejszają odkształcenie próbki przy zginaniu.

EN

Two vinyl ester laminates reinforced with aramid and glass fibres have been tested in dry condition and after immersion in water. Materials were tested for their potential use in marine applications. The reinforcement was in the form of woven hybrid aramid-glass fabric (1) or woven aramid fibre layers interleaved with woven glass fibre layers (2). Accellerated water immersion tests (70°C) have been conducted followed by flexure and interlaminar shear strength (ILSS) tests. Water absorption curves have been plotted (Fig. 1) and diffusion coefficients have been calculated. Despite only slightly higher fraction of hygroscopic aramid fibres moisture absorption saturation values as well as diffusion coefficients were found higher for composite (2). Flexural strength and modulus and interlaminar shear strength have also been found superiour for hybrid fabric-reinforced laminates (Figs. 2, 3). This refers both to the dry and wet condition. It has been demonstrated that water causes serious damage in the microstructure of the laminates consisting mainly of fibre/matrix debonding (Figs. 4, 5). These defects have little effect on the flexural strength properties of the laminates. ILSS and flexural strength of the laminates in the dry and wet condition were very similar. However, the reduction in the elastic modulus and dramatic decrease in the deflection of the samples have been observed following water saturation.