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Η θερµογραφία είναι µία µέθοδος µε την οποία ανιχνεύουµε τις θερµοκρασίες που αναπτύσσονται στις επιφάνειες διαφόρων υλικών. Με την µέθοδο αυτή προσδιορίζουµε και ερµηνεύουµε τις θερµοκρασιακές διαφορές που εµφανίζονται στα υλικά και στην κατασκευή εν γένει και εξάγουµε συµπεράσµατα ως προς την ορθή θερµική θωράκισή της. Στην παρούσα εργασία γίνεται καταγραφή των χαρακτηριστικών εφαρµογών της θερµογραφίας στα δοµικά υλικά. Επίσης γίνεται και η ερµηνεία των διαφόρων φαινοµένων µε θερµοκρασιακά διαγράµµατα. Πηγή: ΕΜΠ, ∆ηµοσιεύσεις Εργαστηρίου Τεχ
Citation preview
: . .
. . ... .- .....
20,0C
33,0C
20
22
24
26
28
30
32
2
2003
ii
iii
. . ... .- .....
2
: 2002-2003 : . . : . . .-. : www.ntua.gr/vitruvius/ress.htm 2003 , 2003
iv
v
1 vi
2 1
2.1 ......................................................................................................................................1
2.2 ................................................................................................................1
2.3 ...............................................................2
2.4 ......................................................................................................3
2.5 ...............................................................................................5
3 6
3.1 , .................................................6
3.2 ............................................................8
3.3 ...................................................10
3.4 .........................................................................12
3.5 ........................................................................................14
3.6 .................................................................15
4 17
5 18
v
2.1: ........................................................................................ 1 2.2: ...................................................................................... 2 2.3: () ............................................................... 2 2.4: ................................................................................... 3 3.1:
.................................................................................................................................... 7 ..................................................................................................... 7 .................................................................................................................. 7 3.2 .. ........................................................ 7 3.3 ............................................................................. 7 3.4 () ..................................................... 8 3.5 () ..................................................... 8 3.6: ........................................................................ 8 3.7:
() ............................................................................... 9 3.8: ()
..................................................................................................................................... 9 3.9:
............................................................................................................................... 10 3.10: ......................... 10 3.11:
() ............................................................................................ 10 3.12: ............................................... 11 3.13:
................................................................................................... 11 3.14:
.................................................................................................................................. 12 3.15 () ........... 12 3.16 ( ) ........... 13 3.17 ( )....................................................... 13 3.18: ............................................................... 14 3.19: ...
............................................................................................................................... 14 3.20:
() ......................................................................................................................................... 15 3.21:
() ........................................................................................................................ 15 3.22:
...................................................................................................................................... 15 3.23:
...................................................................................................................................... 15 3.24 () ............ 16
vi
1
. .
. .
1
2
2.1 . .
2.2 . , . , , . , . .
[W/m*K] .
.
Q = ( /d) * F * (t1 - t2)*z
:
Q
F
t1
t2
d
z
Fourier
2.1:
2
2.3 . ( ) (, ) .
. . .
. , .
Q = ( /x) * F * (tLi t1)
, /x [W/m2K]. .
:
2.2:
2.3: ()
3
Q = K* F * (tLi tLa)*z =
= i * F * (tL t1)*z =
= ( /d) * F * (t1 - t2)*z =
= a * F * (t2 - tLa )*z
:
2.4:
Q
F
(i , a )
tLi
tLa
t1
t2
d
z
2.4 2.4.1
, , . .
. . .
4
:
q= * (14 - 24)
q [w/m2]
Stefan - Boltzmann
K Stefan Boltzmann.
.
2.4.2
, (). .
. . (.. ). 10m ( ). () .
, , , ,
: ( ) , , , .
. ( 0,8).
5
2.5 . . .
. :
( )
:
:
(.. , )
, (.. )
:
0C
( ).
.
.
( )
6
3
3.1 , ( ) .
, , , , :
, .
. ,
.
, , , , .
, . , .
, - . , , ( 20C). , , .
. ,. .
, .
7
3.1:
Q = Q1 = Q2 = Q3 = a * F * (t2 - tLa )*z
t2
tLa
(t2 - tLa ) .
.
2,0C
15,0C
2
4
6
8
1
1
1
3.2 ..
3.3
8
2,3C
13,0C
4
6
8
10
12
2,0C
14,0C
2
4
6
8
10
12
14
3.4 ()
3.5 ()
3.2 .
, .. .
.
3.6:
9
-0,2C
16,3C
0
5
10
15
3.7: ()
14,6C
25,1C
16
18
20
22
24
3.8: () ( 14 C)
10
3.3 .. . 3.9.
3.9:
7,0C
14,0C
8
10
12
14
3.10:
16,7C
35,4C
20
25
30
35
3.11: ()
11
.
3.12:
17,7C
34,2C
20
25
30
3.13:
12
3.4 .
3.14:
18,3C
24,1C
20
22
24
3.15 () ( ) , ( ).
13
16,8C
30,4C
18
20
22
24
26
28
30
3.16 ( ) .
16,6C
28,1C
18
20
22
24
26
28
3.17 ( ) . , . .
14
3.5
3.18:
(.. ). , . ,
10,9C
19,5C
12
14
16
18
3.19: ...
15
3.20:
()
3.21:
()
11,8C
17,3C
12
13
14
15
16
17
3.22:
3.23:
3.6 . , . . , ( ) ( ). , , .
16
16,5C
28,5C
18
20
22
24
26
28
3.24 () , . .
17
4
, ,
,
.
,
, , ,
.
18
5
1364, - - ,
., ., 2, . .., 2002
., ., ., , , 2002
ASTM D4788-88 Standard Test Method for Detecting Delaminations in Bridge Decks Using Infrared Thermography, 2001
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Recktenwald G., Use of superposition to describe heat transfer from multiple electronic components, Mechanical Engineering Department, Portland, 2001
Haralambopoulos D. A. and G.F. Paparsenos, Assesing the thermal insulation of old buildings-the need for in situ spot measurements of thermal resistance and planar infrared thermography, Energy Convers, Mgmt Vol. 39, No , pp 65-79, 1998
Titman D. J., Applications of thermography in non-destructive testing of structures, NDT &E International 34 p.149-154, 2001
Sakagami T., Kubo S., Development of a new non- destructive testing technique for quantitative evaluations of delaminating defects in concrete structures based on phase delay measurement using lock- in thermography, Infrared physics & Technology, 43 p.311-316, 2002