Ghostscript wrapper for D:\Digitalizacja\MTS84_t22z1_4_PDF_artyku³y\mts84_t22z1_2.pdf M ECH AN I KA TEORETYCZNA I STOSOWANA 1/ 2, 22 (1984) EQU ATION S OF TH E SH ELIS WITH IN CLUSION S ALON G ON E OF TH E PARAMETER LIN ES IWON A C I E L E C K A SYLWESTER K O N I E C Z N Y Politechnika Ł ódzka Instytut Inż ynierii Budowlanej 1. Basic equations of shells I n th e paper of Cz. WO Ź N I AK [1], [2] bases of analytical mechanics of material continuum h ave been given an d am on g oth er things equation s of m otion and boundary conditions have been form ulated for shells as a body with in tern al constraints. F o r static problem s, takin g th e function of m otion defined by the equation ) YeF th e equation s of m otion have th e form [1] i *+ / *= 0, an d th e boun dary con dition s are defined by the following relations [1] 8d k ds Th e functions tp an d d m ay be depen den t on each oth er an d satisfy certain conditions [1] « y (Z, *(Z , 0, d(Z, t), v>(Z, t), W(Z, 0) = 0, Zen pjz, MZ, t), d(z, t), mz, t), dd(z, o) = o, zG en. u 2. Kinetic contact conditions for shells with inclusions I n order to take in to accoun t th e influence of the inclusion on the m otion of the shell, we also h an dle th e inclusion as m aterial con tin uum [3]. Let u s assume t h at t h e n otion of inclusion from th e reference configuration I R to the actual configuration is described by th e function x = %{X, t), X — (Xv) e J R . 116 J. CIELECKA, S. KON IECZN Y I n accordance with th e analytical mechanics of m aterial con tin uum , the field of external body loads b an d the field of external surface loads p R an d th e field of in tern al con tact forces i R s f R n R (T R is th e first Piola- Kirchhoff ten sor of stress) should satisfy th e prin - ciple of virtual work [2] - X) • fydv R + f h • S%da R = / fg • V(6x)dv R , (5) where g R is the mass density of material of th e inclusion in th e reference con figuration We put th at th e field of external surface loads affecting th e boun dary of in clusion 8I R or its part is given by the field of internal forces of the shell P k - T krn v , (6) where n R = (n) y is a un it norm al vector in th e place of con tact of th e shell with th e boun dary of inclusion. Assuming th at th e inclusion is closely connected with t h e shell, the functions of m otion for the shell % an d the inclusion % have the sam e values on th e com m on surface S R m 8B R ndI R . Let the motion of arbitrary particle of inclusion be given in the following form : i(X, t) =
3 2 3 2 0
- D2222 0 D2222
'0 0
L^2.22
0
. £ 2 2 3 0 Z»322
0 £>322 0
¥2, 2
Io ~Dl13 °
iv
0 0 D2''
P = 0, (12)
and
= 0
where A1 is Lagrange multipler which corresponds to eq. (11). In the above system equations
the components of function of motion are denoted in the following manner
— o
%pv S ipy — y)y, dy = dy—dy, (13)
where ^ = (0, X2, R), d - ( 0 , 0 , 1 ) . The factors at the unknown components of function
of motion depend on Lame" constants /W, A and thickness h and radius R of the cylindrical
shell.
' £ " 3 = ^ _ ' £
2 2 3 = RD223 - hX,
£3232 _ £322 _ . £22 _ £3232 _
h2 jr>322 =
n2222 _ I - i
D ~T2
(14)
The kinetic contact conditions for shell (9) should be reduced to the form including
the components of the function of motion of shell ijf and d only. Taking into account
the equality of the deformation functions of the shell and of the inclusion on the common
surface 5^ we obtain the mentioned below relations between components
Vv = y ~{dP+d (15)
We determine with sing „ + " the components of the vector of motion for the part of shell
which is oriented by the positive unit normal vector nR while crossing the axis of the in-
clusion and with sing „—" those for the one oriented by the vector — nR. The kinetic
contact conditions by the application of the relations (15) have the form
SH E LLS WI T H I N C LU SI ON S 119
£ , 2222
0
- ~D
2222
0
£ 72222
0
0
~L
322
* £ 2222
0
0
i . £2233
— -
0
£,3232
0
'_ £,3232
0
£ 73232
£ , 223
£,2222
0
i . JTJT2222
0
£ 72222
0
- u Ł '"
4»"4
J_£ 2323
* 1- 2332
- yL 3 3 3
- Z > 2 2 3
*• r 1 1 3
£ 3 2 2
—
2R
L
J_£ > 223_^_£ 322
_ 1 L 2 3 2 3 _ ^
̂ 7- 2332
-
T
Ł
_ £ > 2222 0
0 D3232
0 - {
_ £ 7 2 2 2 2
0
0
£ , 322
0
0
_ £ ,3232
0
£ 73232
- .02222
0
- i - £ 72222
0
_ £ 72222
0
^2, 2
V3.2
J + ,
**2» 2
^2 , 2
^3 . 2
- dl 2
0
*• T3 2 2
TŁ
__
' 7)322_/ £3232
2 2
1 ł - 3232
~~2
Ł
£ 7322
0
_ £ ) 3 2 2
i/
0
• )322 * 7 3223
_ ^ L 2 3 3 2
^ £ 2 2 2 2
0
0
~vi~
vt
Ił
V>2
+
/ 2
/ 3
?22
/ "
Z 3 2
f33
= [0]
where
0,5/ 0,5/
[ J
0,5/0,5/ 0,5/
/» = [ / p zwfi, / " - [ /
05/ 05/
[ /
- 0, 5/
0,5/
/
- 0, 5/
0,5/
- 0,5/
(1 6)
(17)
- 0,5/
120 J. CIELECKA, S. KON IECZN Y
and
(£ )4&r]
L 2 2 2 2 = lh(U2fi),
L
2233 = J Ł L3 2 2 = Ihl,
£3232 = £2332 = £ 3223 = / / ^
Ji,X — Lame" constants for material of the in clusion :
Th e first three equations (12) together with kinetic con tact con dition s (16) an d suitable
boundary conditions let us calculate the com pon en ts of th e function of m otion of t h e
shell an d th e internal resultan t forces in t h e shell an d the inclusion an d also th e reaction
forces of constraints loading the shell which secure t h e deform ation con sisten t with t h e
assumed constraints. The internal resultan t forces m ay be calculated from relation s given
in [3] and for the shell being considered they have th e following form
12 "2'2
M
21 = — p ^ f2 , 2 + —
fihyJ
3
,
2
.
M
12 = M 21 = M 31 = H12 - H21 = H31 = 0.
The internal forces in th e inclusion which are different from zero are determ ined by t h e
relations
if11 =
(20)
SHELLS WITH INCLUSIONS 121
The reaction forces of constraints for the shell may be calculated from [1] and for this
shell they have the form
P = 0
= 0,
T
4. Example
Let us consider a cylindrical shell of length L in which two rings have been placed.
The Young's modulus for the material of rings is 20% greater than that for the material
of the shell but the Poisson's ratios are the same. The shell is loaded a uniform load p
along its length (fig. 2) and simple-supported at its ends. It is assumed that the thickness
of shell is h = 0,04 m, the radius of the middle surface of shell R = 0,60 m and the width
of a ring / = 0,03 m.
run
CM
TTTT
t
1 /
A
if~
t t
L
3
t t t
L
y
L
t t t
L
t
1̂
Fig. 2
Solving this example, the region occupied by shell in the reference configuration has
been assumed as the sum of three regions B\, Bxl, flJJ1 (fig. 3).
122 J. QELECKA, S. KON IECZN Y
Fig. 3
Q
LO
O L O
u i u i
U>LO
0 0.13L 0,17L0,27L
8 N
F ig. 4
After calculations vertical displacements of the poin ts of t h e m iddle surface of th e
cylindrical shell with two rin g inclusions and the change of ben din g couple M 22 along
the length of the shell have been shown on fig. 4 as and exam ple.
Reference
1. Cz. WOŹ N IAK, W stę p do mechaniki analitycznej kontinuum materialnego, Cz. I ., Kontinua z wię zami
geometrycznymi, IPPT P AN W- wa 1975.
2. Cz. WOŹ N IAK, Constrained Continuous Media, I , I I , I I I , Buli. Acad. P olon. Sd. Ser. Sci. Techn. 21.1973.
3. I . CIELECKA, S. KON IECZN Y, Równania powł ok o skokowej niejednorodnoici, Zeszyty N aukowe P Ł .,
Budownictwo z. 27, 1981.
SH ELLS WI TH IN CLUSION S 123
P e 3 IO M e
yP AB H E H H E O E O J I O ^ E K C H H K J H 0 3 I M M H BtfOJI b O flH O rO C EM Efł C TBA
n AP AM E T P H ^ E C K H X JI H H H K
H cxoflH H3 ypaBHeHHH TeopHH cn jion n ibix cpefl c C BH 3«M H ccpopMyjiHpOBaHHOJi1- !. BO3BH SKOM [ 1 , 2]
npeflJiaraeM MaieMaTiwecKyio iwoflenL o6oJio*ieK H3 M aiepn an a o cKain