122
E. Kormanikova et al.
a)
b)
2
2.2
2.4
2.6
2.8
3
3.2
3.4
3.6
3.8
Length [m]
45
50
55
60
65
70
75
80
85
Fundamental frequency [Hz]
Fundamental frequency, h=0.04
[0]3 Analytical
[0]3 Numerical
[0/90/0] Analytical
[0/90/0] Numerical
2
2 . 2
2 . 4
2.6
2.8
3
3.2
3.4
3.6
3.8
Length [m]
75
80
85
90
95
100
105
110
115
120
125
Fundamental frequency [Hz]
Fundamental frequency, h=0.12m
[0]3 Analytical
[0]3 Numerical
[0/90/0] Analytical
[0/90/0] Numerical
Fig. 2. Fundamental frequencies versus length for sandwich with [0] 3 and [0/90/0] CFRP faces,
numerical and analytical solution, L = 2.9 m, a) h = 0.04 m b) h = 0.12
5 Conclusion
The periodic microstructure model was used for homogenization of unidirectional fiber
reinforced composite. Computational program MATLAB was used to calculate the effective material properties of laminate faces [12, 13]. The FSDT was considered for free
vibration analysis. The influence of the variable length and fiber orientation of CFRP
faces with [0] 3 and [0/90/0] layout to natural frequencies was presented. It is also possible to observe the increase in frequency with increasing the thickness of the panel and
by reducing the length of panel for both [0] 3 and [0/90/0] CFRP faces sandwich panels.