Wave reflection and transmission in composite beams containing ...
Wave reflection and transmission in composite beams containing ...
Wave reflection and transmission in composite beams containing ...
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ARTICLE IN PRESS<br />
W.-C. Yuan et al. / Journal of Sound <strong>and</strong> Vibration 313 (2008) 676–695 687<br />
Magnitude<br />
180<br />
ω/ω c<br />
3<br />
0.6<br />
R<br />
0<br />
12<br />
R 0<br />
R<br />
2<br />
22<br />
11<br />
0.3<br />
R<br />
-45<br />
-45<br />
21 1<br />
(2) (1)<br />
ω c ω c ω c<br />
1.5<br />
180 7<br />
ω c<br />
(2)<br />
ω c<br />
(1)<br />
ω c<br />
ω/ω c<br />
1.2<br />
135<br />
6<br />
135<br />
90<br />
5<br />
90<br />
0.9<br />
4<br />
45<br />
45<br />
0<br />
-90 0<br />
-90<br />
0 1 2 3 4<br />
0 1 2 3 4<br />
Phase (deg)<br />
Fig. 5. Reflection coefficients (R jk , for j, k ¼ 1,2) (h 1 /h ¼ 0.4) under closed delam<strong>in</strong>ation condition (solid l<strong>in</strong>e: magnitude; dotted l<strong>in</strong>e:<br />
phase). <strong>Wave</strong> <strong>reflection</strong> from (a) first flexural mode <strong>and</strong> (b) second flexural mode.<br />
Magnitude<br />
Phase (deg)<br />
2.0<br />
(2) (1)<br />
ω c ω c ω c<br />
135<br />
25<br />
(2) (1)<br />
ω c ω c ω c<br />
180<br />
Magnitude<br />
1.5<br />
1.0<br />
0.5<br />
(1)<br />
(1) T 21<br />
T 11<br />
(1)<br />
T 31<br />
90<br />
45<br />
0<br />
-45<br />
Phase (deg)<br />
Magnitude<br />
20<br />
15<br />
10<br />
5<br />
(1)<br />
T 22<br />
(1)<br />
T 12<br />
(1)<br />
T 32<br />
135<br />
90<br />
45<br />
0<br />
-45<br />
-90<br />
Phase (deg)<br />
0 -90<br />
0 1 2 3 4<br />
ω/ω c<br />
0<br />
-135<br />
0 1 2 3 4<br />
ω/ω c<br />
Fig. 6. Magnitudes <strong>and</strong> phases of <strong>transmission</strong> coefficients ðT ð1Þ<br />
jk ; for j ¼ 1,2,3, k ¼ 1,2) <strong>in</strong> upper sub-beam (h 1/h ¼ 0.4) under open<br />
delam<strong>in</strong>ation condition (solid l<strong>in</strong>e: magnitude; dotted l<strong>in</strong>e: phase). <strong>Wave</strong> <strong>transmission</strong> from (a) first flexural mode <strong>and</strong> (b) second flexural<br />
mode.<br />
2.0<br />
(2) (1)<br />
ω c ω c ω c<br />
135<br />
25<br />
(2) (1)<br />
ω c ω c ω c<br />
180<br />
Magnitude<br />
1.5<br />
1.0<br />
0.5<br />
(2)<br />
T 11<br />
(2)<br />
T 21<br />
(2)<br />
T 31<br />
90<br />
45<br />
0<br />
-45<br />
Phase (deg)<br />
Magnitude<br />
20<br />
15<br />
10<br />
5<br />
(2)<br />
T 22<br />
(2)<br />
T 12<br />
(2)<br />
T 32<br />
135<br />
90<br />
45<br />
0<br />
-45<br />
-90<br />
Phase (deg)<br />
0<br />
-90<br />
0 1 2 3 4<br />
ω/ω c<br />
0<br />
-135<br />
0 1 2 3 4<br />
ω/ω c<br />
Fig. 7. Magnitudes <strong>and</strong> phases of <strong>transmission</strong> coefficients (T ð2Þ<br />
jk , for j ¼ 1,2,3, k ¼ 1,2) <strong>in</strong> lower sub-beam (h 1/h ¼ 0.4) under open<br />
delam<strong>in</strong>ation condition (solid l<strong>in</strong>e: magnitude; dotted l<strong>in</strong>e: phase). <strong>Wave</strong> <strong>transmission</strong> from (a) first flexural mode <strong>and</strong> (b) second flexural<br />
mode.