Experimental and numerical investigation of the damping of flax–epoxy composite plates

2019 ◽  
Vol 208 ◽  
pp. 426-433 ◽  
Author(s):  
S. Mahmoudi ◽  
A. Kervoelen ◽  
G. Robin ◽  
L. Duigou ◽  
E.M. Daya ◽  
...  
Keyword(s):  
Numerical Investigation ◽  
Epoxy Composite ◽  
Composite Plates

Effect of Delamination on Natural Frequencies of E-glass and S-glass Epoxy Composite Plates

2021 ◽  
Author(s):  
P. K. Karsh ◽  
Bindi Thakkar ◽  
R. R. Kumar ◽  
Abhijeet Kumar ◽  
Sudip Dey
Keyword(s):  
Natural Frequencies ◽  
Epoxy Composite ◽  
Orientation Angle ◽  
Laminated Composite ◽  
Composite Plates ◽  
Mode Shapes ◽  
Transverse Shear Deformation ◽  
The Finite Element Method ◽  
Modes Of Failure ◽  
Ply Orientation

The delamination is one of the major modes of failure occurring in the laminated composite due to insufficient bonding between the layers. In this paper, the natural frequencies of delaminated S-glass and E-glass epoxy cantilever composite plates are presented by employing the finite element method (FEM) approach. The rotary inertia and transverse shear deformation are considered in the present study. The effect of parameters such as the location of delamination along the length, across the thickness, the percentage of delamination, and ply-orientation angle on first three natural frequencies of the cantilever plates are presented for S-glass and E-glass epoxy composites. The standard eigenvalue problem is solved to obtain the natural frequencies and corresponding mode shapes. First three mode shape of S-Glass and E-Glass epoxy laminated composites are portrayed corresponding to different ply angle of lamina.

Investigation of Bending Fatigue of Composite Plates by Using Infrared Thermography

2011 ◽  
Vol 268-270 ◽  
pp. 406-411 ◽  
Author(s):  
Ömer Sinan Şahin ◽  
Murat Selek ◽  
Şirzat Kahramanlı
Keyword(s):  
Infrared Thermography ◽  
Heat Generation ◽  
Temperature Rise ◽  
Epoxy Composite ◽  
Composite Plates ◽  
Fatigue Loading ◽  
Thermal Camera ◽  
Thermal Images ◽  
Bending Fatigue ◽  
Damage Initiation

In this study, the temperature rise of composite plates with a hole during fatigue loading was investigated. Woven glass/epoxy composite plates with eight plies were subjected to bending fatigue loading and materials were observed by using a thermal camera during the test. Previous works showed that a heat generation can form due to internal friction and damage formation. Therefore, a thermographic infrared imaging system was used to detect the temperature rise of composite specimens. During the tests, the thermal images of the specimens have been recorded by a thermal camera and then transferred to the image processing program which has been developed by using MATLAB. By using these thermal images, the spot temperatures of the specimen were obtained by using artificial neural networks. The obtained temperatures show local increase at places where the heat generation localized. These regions considered being the probable damage initiation sites. It is shown in this study that most probable damage initiation zones in the woven glass/epoxy composite material can be detected by using infrared thermography (IRT) approach prior to failure.

Subsonic and Intersonic Failure of Composites: High-Speed Optical and Thermographic Measurements and Numerical Simulations

2000 ◽  
Author(s):  
A. J. Rosakis ◽  
D. Coker ◽  
C. Yu ◽  
M. Ortiz
Keyword(s):  
Crack Growth ◽  
High Speed ◽  
Large Scale ◽  
Wave Speed ◽  
Epoxy Composite ◽  
Shear Crack ◽  
Crack Tip ◽  
Composite Plates ◽  
Crack Face ◽  
Shear Wave Speed

Abstract In this paper dynamic fracture behavior of unidirectional graphite-epoxy composite plates is investigated experimentally and numerically. Crack propagation experiments are conducted on thick unidirectional graphite-epoxy composite plates subjected to in-plane, symmetric and asymmetric, impact loading. The coherent gradient sensing technique (CGS) is used in conjunction with high-speed photography to visualize the crack growth events. Cracks are found to propagate at subsonic speeds in the Mode-I case, whereas in both mixed mode and Mode-II the crack tip speed clearly exceeds the shear wave speed of the laminate. In the case of symmetric loading (Mode-I), the crack tip speeds approach the Rayleigh wave speed of the composite (1500 m/s), however it never exceeds it as predicted by asymptotic analysis. The situation is found to be entirely different for growing shear (Mode-II) cracks. A shock wave emanating from the crack tip is observed in the optical patterns. This provides direct evidence that the crack propagates faster than the shear wave speed of the composite. The crack tip speed is then observed to jump to a level close to the axial longitudinal wave speed along the fibers (7500 m/s) and then to stabilize to a lower level of approximately 6500 m/s. This speed corresponds to the speed at which the energy release rate required for shear crack growth is non-zero as determined from asymptotic analysis. The CGS interferograms also reveal the existence of large-scale frictional contact of the crack faces behind the moving shear cracks. In addition high speed thermographic measurements are conducted that show concentrated hot spots behind the crack tip indicating crack face frictional contact. Finally, these experiments are modeled by a detailed dynamic finite element calculation involving cohesive elements, newly developed adaptive remeshing using subdivision and edge collapse, composites element, and penalty contact. The numerical calculations are calibrated on the basis of fundamental material properties measured in the laboratory. The numerical methodology is subsequently validated by direct comparison to optical experimental measurements (crack speed record and near tip deformation field structure). For shear crack growth the numerics also reveal the experimentally observed shock wave structure and confirm the optical observation of large-scale crack face contact.

scholarly journals Model updating of uncertain parameters of carbon/epoxy composite plates from experimental modal data

2019 ◽  
Vol 455 ◽  
pp. 380-401 ◽  
Author(s):  
M. Cuadrado ◽  
J.A. Artero-Guerrero ◽  
J. Pernas-Sánchez ◽  
D. Varas
Keyword(s):  
Model Updating ◽  
Epoxy Composite ◽  
Composite Plates ◽  
Uncertain Parameters ◽  
Modal Data

The effect of low-velocity impact on the flexural strength of E-glass/epoxy composite plates

2020 ◽  
Vol 34 (5) ◽  
pp. 1879-1886
Author(s):  
Pham Xuan Quang ◽  
Satrio Wicaksono ◽  
Tatacipta Dirgantara ◽  
Bambang Kismono Hadi
Keyword(s):  
Flexural Strength ◽  
Epoxy Composite ◽  
Composite Plates ◽  
Low Velocity Impact ◽  
Low Velocity ◽  
Velocity Impact
Sign in / Sign up

Export Citation Format

Share Document