Influence of Single and Multiple Skin-Core Debonding on Free Vibration Characteristics of Innovative GFRP Sandwich Panels
An Australian manufacturer has fabricated an
innovative GFRP sandwich panel made from E-glass fiber skin and a
modified phenolic core for structural applications. Debonding, which
refers to separation of skin from the core material in composite
sandwiches, is one of the most common types of damage in
composites. The presence of debonding is of great concern because it
not only severely affects the stiffness but also modifies the dynamic
behaviour of the structure. Generally it is seen that the majority of
research carried out has been concerned about the delamination of
laminated structures whereas skin-core debonding has received
relatively minor attention. Furthermore it is observed that research
done on composite slabs having multiple skin-core debonding is very
limited. To address this gap, a comprehensive research investigating
dynamic behaviour of composite panels with single and multiple
debonding is presented. The study uses finite-element modelling and
analyses for investigating the influence of debonding on free
vibration behaviour of single and multilayer composite sandwich
panels. A broad parametric investigation has been carried out by
varying debonding locations, debonding sizes and support conditions
of the panels in view of both single and multiple debonding.
Numerical models were developed with Strand7 finite element
package by innovatively selecting the suitable elements to diligently
represent their actual behavior. Three-dimensional finite element
models were employed to simulate the physically real situation as
close as possible, with the use of an experimentally and numerically
validated finite element model. Comparative results and conclusions
based on the analyses are presented. For similar extents and locations
of debonding, the effect of debonding on natural frequencies appears
greatly dependent on the end conditions of the panel, giving greater
decrease in natural frequency when the panels are more restrained.
Some modes are more sensitive to debonding and this sensitivity
seems to be related to their vibration mode shapes. The fundamental
mode seems generally the least sensitive mode to debonding with
respect to the variation in free vibration characteristics. The results
indicate the effectiveness of the developed three dimensional finite
element models in assessing debonding damage in composite
sandwich panels.
[1] Van Erp G, Rogers D. A highly sustainable fibre composite building
panel. In: Proceedings of the International Workshop on Fibre
Composites in Civil Infrastructure – Past, Present and Future,
University of Southern Queensland, Toowoomba, Queensland,
Australia, 1-2 December 2008. pp. 17-23
[2] Mousa, MA & Uddin N, ‘Structural behaviour and modeling of fullscale
composite structural insulated wall panels’, Engineering Structures
vol. 41, pp. 320-334,2012.
[3] Aravinthan, T , ‘Research and Development of Fibre Composites in
Civil Infrastructure - The Australian Experience’, KEY 06,Third Asia-
Pacific Conference on FRP in Structures (APFIS2012), 2-4 February
2012, Hokkaido University Conference Hall, Sapporo, Japan.
[4] M. Idriss, A. Mahi, M. Assarar and R. Guerjouma, “Damping analysis in
cyclic fatigue loading of sandwich beams with debonding,” Composites:
Part B, vol. 44, pp. 597-603, 2013.
[5] V.N. Burlayenko and T. Sadowsky, “Nonlinear dynamic analysis of
harmonically excited debonded sandwich plates using finite element
modelling,” Composite Structures, vol. 108, pp. 354-366, 2014.
[6] STRAND7, Strand7 finite element analysis FEA software, Release 2.4.1,
Sydney, Australia J. 2010, (website: www.strand7.com).
[7] Awad, Z.K., Aravinthan, T. & Yan Zhuge “Investigation of the free
vibration behaviour of an innovative GFRP sandwich floor panel”,
Construction and Building materials, vol.37, pp.209-219, 2012.
[8] I. Jayatilake , W. Karunasena and W. Lokuge, “Dynamic behaviour of
debonded GFRP composite beams,” Journal of Multifunctional
Composites, vol. 1 (2), pp. 113-122, 2013
[1] Van Erp G, Rogers D. A highly sustainable fibre composite building
panel. In: Proceedings of the International Workshop on Fibre
Composites in Civil Infrastructure – Past, Present and Future,
University of Southern Queensland, Toowoomba, Queensland,
Australia, 1-2 December 2008. pp. 17-23
[2] Mousa, MA & Uddin N, ‘Structural behaviour and modeling of fullscale
composite structural insulated wall panels’, Engineering Structures
vol. 41, pp. 320-334,2012.
[3] Aravinthan, T , ‘Research and Development of Fibre Composites in
Civil Infrastructure - The Australian Experience’, KEY 06,Third Asia-
Pacific Conference on FRP in Structures (APFIS2012), 2-4 February
2012, Hokkaido University Conference Hall, Sapporo, Japan.
[4] M. Idriss, A. Mahi, M. Assarar and R. Guerjouma, “Damping analysis in
cyclic fatigue loading of sandwich beams with debonding,” Composites:
Part B, vol. 44, pp. 597-603, 2013.
[5] V.N. Burlayenko and T. Sadowsky, “Nonlinear dynamic analysis of
harmonically excited debonded sandwich plates using finite element
modelling,” Composite Structures, vol. 108, pp. 354-366, 2014.
[6] STRAND7, Strand7 finite element analysis FEA software, Release 2.4.1,
Sydney, Australia J. 2010, (website: www.strand7.com).
[7] Awad, Z.K., Aravinthan, T. & Yan Zhuge “Investigation of the free
vibration behaviour of an innovative GFRP sandwich floor panel”,
Construction and Building materials, vol.37, pp.209-219, 2012.
[8] I. Jayatilake , W. Karunasena and W. Lokuge, “Dynamic behaviour of
debonded GFRP composite beams,” Journal of Multifunctional
Composites, vol. 1 (2), pp. 113-122, 2013
@article{"International Journal of Mechanical, Industrial and Aerospace Sciences:69849", author = "Indunil Jayatilake and Warna Karunasena and Weena Lokuge", title = "Influence of Single and Multiple Skin-Core Debonding on Free Vibration Characteristics of Innovative GFRP Sandwich Panels", abstract = "An Australian manufacturer has fabricated an
innovative GFRP sandwich panel made from E-glass fiber skin and a
modified phenolic core for structural applications. Debonding, which
refers to separation of skin from the core material in composite
sandwiches, is one of the most common types of damage in
composites. The presence of debonding is of great concern because it
not only severely affects the stiffness but also modifies the dynamic
behaviour of the structure. Generally it is seen that the majority of
research carried out has been concerned about the delamination of
laminated structures whereas skin-core debonding has received
relatively minor attention. Furthermore it is observed that research
done on composite slabs having multiple skin-core debonding is very
limited. To address this gap, a comprehensive research investigating
dynamic behaviour of composite panels with single and multiple
debonding is presented. The study uses finite-element modelling and
analyses for investigating the influence of debonding on free
vibration behaviour of single and multilayer composite sandwich
panels. A broad parametric investigation has been carried out by
varying debonding locations, debonding sizes and support conditions
of the panels in view of both single and multiple debonding.
Numerical models were developed with Strand7 finite element
package by innovatively selecting the suitable elements to diligently
represent their actual behavior. Three-dimensional finite element
models were employed to simulate the physically real situation as
close as possible, with the use of an experimentally and numerically
validated finite element model. Comparative results and conclusions
based on the analyses are presented. For similar extents and locations
of debonding, the effect of debonding on natural frequencies appears
greatly dependent on the end conditions of the panel, giving greater
decrease in natural frequency when the panels are more restrained.
Some modes are more sensitive to debonding and this sensitivity
seems to be related to their vibration mode shapes. The fundamental
mode seems generally the least sensitive mode to debonding with
respect to the variation in free vibration characteristics. The results
indicate the effectiveness of the developed three dimensional finite
element models in assessing debonding damage in composite
sandwich panels.", keywords = "Debonding, free vibration behaviour, GFRP
sandwich panels, three dimensional finite element modelling.", volume = "9", number = "5", pages = "816-5", }