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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.

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