4.61 SHELL61 Axisymmetric-Harmonic Structural Shell

4.61 SHELL61 Axisymmetric-Harmonic Structural Shell (UP19980821 ) SHELL61 has four degrees of freedom at each node: translations in the nodal x, y, and z directions and a rotation about the nodal z axis. The loading may be axisymmetric or nonaxisymmetric. Various loading cases are described in Section 2.9. An axisymmetric conical shell element with nonlinear material properties is described in Section 4.51.

Extreme orientations of the conical shell element result in a cylindrical shell element or an annular disc element. The shell element may have a linearly varying thickness. See Section 14.61 of the ANSYS Theory Reference for more details about this element.

Figure 4.61-1 SHELL61 Axisymmetric-Harmonic Structural Shell



4.61.1 Input Data

The geometry, node locations, and the coordinate system for this element are shown in Figure 4.61-1. The element is defined by two nodes, two end thicknesses, the number of harmonic waves (MODE), a symmetry condition (ISYM), and the orthotropic material properties. The element coordinate system is shown in Figure 4.61-2. is in the tangential (hoop) direction. The MODE or ISYM parameters are discussed in detail in Section 2.9.

The material may be orthotropic, with nine elastic constants required for its description. Properties not input default as described in Section 2.4. The element loading may be input as any combination of harmonically varying temperatures and pressures. Harmonically varying nodal forces, if any, should be input on a full 360 basis.

The element may have variable thickness. The thickness is assumed to vary linearly between the nodes. If the element has a constant thickness, only TK(I) is required. Real constant ADMSUA is used to define an added mass per unit area.

Element loads are described in Section 2.7. Harmonically varying pressures may be input as surface loads on the element faces as shown by the circled numbers on Figure 4.61-1. Positive pressures act into the element. The pressures are applied at the surface of the element rather than at the centroidal plane so that some thickness effects can be considered. These include the increase or decrease in size of surface area the load is acting on and (in the case of a non-zero Poisson's ratio) an interaction effect causing the element to grow longer or shorter under equal pressures on both surfaces. Material properties EY, PRXY, and PRYZ (or EY, NUXY, and NUYZ) are required for this effect.

Harmonically varying temperatures may be input as element body loads at the four corner locations shown in Figure 4.61-1. The first corner temperature T1 defaults to TUNIF. If all other temperatures are unspecified, they default to T1. If only T1 and T2 are input, T3 defaults to T2 and T4 defaults to T1. For any other input pattern, unspecified temperatures default to TUNIF.

KEYOPT(1) is used for temperature loading with MODE greater than zero and temperature dependent material properties. Material properties may only be evaluated at a constant (nonharmonically varying) temperature. If MODE equals zero, the material properties are always evaluated at the average element temperature. KEYOPT(3) is used to include or suppress the extra displacement shapes.

A summary of the element input is given in Table 4.61-1. A general description of element input is given in Section 2.1.

Table 4.61-1 SHELL61 Input Summary

Element Name

SHELL61

Nodes

I, J

Degrees of Freedom

UX, UY, UZ, ROTZ

Real Constants

TK (I), TK (J). (TK (J) defaults to TK (I)), ADMSUA

Material Properties

EX, EY, EZ, PRXY, PRYZ, PRXZ (or NUXY, NUYZ, NUXZ), ALPX, ALPZ, DENS, GXZ, DAMP. (X is meridional, Y is through-the-thickness, and Z is circumferential.)

Surface Loads

Pressures:
face 1 (I-J) (top, in -Y direction)
face 2 (I-J) (bottom, in +Y direction)

Body Loads

Temperatures: T1, T2, T3, T4

Mode Number

Input mode number on MODE command

Special Features

Stress stiffening

Loading Condition

Input for ISYM on MODE command
1 - Symmetric loading
-1 - Anti-symmetric loading

KEYOPT(1)

Used only for MODE greater than zero
0 - Use temperatures for thermal bending (evaluate material properties at TREF)
1 - Use temperatures for material property evaluation (thermal bending not permitted - ALPX and ALPZ must be zero)

KEYOPT(3)

0 - Include extra displacement shapes
1 - Suppress extra displacement shapes

KEYOPT(4)

0 - No printout of member forces and moments
1 - Print out member forces and moments in the element coordinate system

KEYOPT(6)

Controls location of element solution output:
0 - Output solution at mid-length only
N
- Output solution at N equally spaced interior points and at end points (where N = 1, 3, 5, 7 or 9)


4.61.2 Output Data

The solution output associated with the element is in two forms:

Several items are illustrated in Figure 4.61-2. The printout may be displayed at the centroid, at the end points and at N equally spaced interior points, where N is the KEYOPT(6) value. For example, if N=3, printout will be produced at end I, 1/4 length, mid-length (centroid), 3/4 length, and at end J. Printout location number 1 is always at end I. Stress components which are inherently zero are printed for clarity.

In the displacement printout, the UZ components are out-of-phase with the UX and UY components. For example, in the MODE=1, ISYM=1 loading case, UX and UY are the peak values at =0 and UZ is the peak value at =90. We recommend that you always use the angle field on the SET command when postprocessing the results. For more information about harmonic elements, see Section 2.9

A general description of solution output is given in Section 2.2. See the ANSYS Basic Analysis Procedures Guide for ways to view results.

Figure 4.61-2 SHELL61 Stress Output



The following notation is used in Table 4.61-2:

A colon (:) in the Name column indicates the item can be accessed by the Component Name method [ETABLE, ESOL] (see Section 2.2.2). The O and R columns indicate the availability of the items in the file Jobname.OUT (O) or in the results file (R), a Y indicates that the item is always available, a number refers to a table footnote which describes when the item is conditionally available, and a - indicates that the item is not available.

Table 4.61-2 SHELL61 Element Output Definitions

Name

Definition

O

R

EL

Element number

Y Y
NODES

Nodes - I, J

Y Y
MAT

Material number

Y Y
LENGTH

Distance between node I and node J

Y Y
CENT: X, Y

Global coordinates XC, YC

Y Y
TEMP

Temperatures T1, T2, T3, T4

Y Y
PRES

Pressures P1 (top) at nodes I,J; P2 (bottom) at nodes I,J

Y Y
MODE

Number of waves in loading

Y Y
ISYM

Loading key: 1 = symmetric, -1 = anti-symmetric

Y Y
T(X, Z, XZ)

In-plane element X, Z, and XZ forces at KEYOPT(6) location(s)

Y Y
M(X, Z, XZ)

Out-of-plane element X, Z, and XZ moments at KEYOPT(6) location(s)

Y Y
MFOR(X, Y, Z), MMOMZ

Member forces and member moment for each node in the element coordinate system

1 Y
PK ANG

Angle where stresses have peak values: 0 and 90/MODE degrees. Blank if MODE=0.

Y Y
S(M, THK, H, MH)

Stresses (meridional, through-thickness, hoop, meridional-hoop) at PK ANG locations, repeated for top, middle, and bottom of shell

Y Y
EPEL(M, THK, H, MH)

Elastic strains (meridional, through-thickness, hoop, meridional-hoop) at PK ANG locations, repeated for top, middle, and bottom of shell

Y Y
EPTH(M, THK, H, MH)

Thermal strains (meridional, through-thickness, hoop, merid.-hoop) at PK ANG locations, repeated for top, middle, and bottom of shell

Y Y
1. These items are printed only if KEYOPT(4)=1.

Table 4.61-3 lists output available through the ETABLE command using the Sequence Number method. See Chapter 5 of the ANSYS Basic Analysis Procedures Guide and Section 2.2.2.2 of this manual for more information. The following notation is used in Table 4.61-3:

Table 4.61-3 SHELL61 (KEYOPT(6)= 0 or 1) Item and Sequence Numbers for the ETABLE and ESOL Commands

KEYOPT(6) = 0 or 1

Name

Item

I

IL1

J

Top

SM

LS

1 13 25
STHK

LS

2 14 26
SH

LS

3 15 27
SMH

LS

4 16 28
EPELM

LEPEL

1 13 25
EPELTHK

LEPEL

2 14 26
EPELH

LEPEL

3 15 27
EPELMH

LEPEL

4 16 28
EPTHM

LEPTH

1 13 25
EPTHTHK

LEPTH

2 14 26
EPTHH

LEPTH

3 15 27
EPTHMH

LEPTH

4 16 28
Mid

SM

LS

5 17 29
STHK

LS

6 18 30
SH

LS

7 19 31
SMH

LS

8 20 32
EPELM

LEPEL

5 17 29
EPELTHK

LEPEL

6 18 30
EPELH

LEPEL

7 19 31
EPELMH

LEPEL

8 20 32
EPTHM

LEPTH

5 17 29
EPTHTHK

LEPTH

6 18 30
EPTHH

LEPTH

7 19 31
EPTHMH

LEPTH

8 20 32
Bot

SM

LS

9 21 33
STHK

LS

10 22 34
SH

LS

11 23 35
SMH

LS

12 24 36
EPELM

LEPEL

9 21 33
EPELTHK

LEPEL

10 22 34
EPELH

LEPEL

11 23 35
EPELMH

LEPEL

12 24 36
EPTHM

LEPTH

9 21 33
EPTHTHK

LEPTH

10 22 34
EPTHH

LEPTH

11 23 35
EPTHMH

LEPTH

12 24 36
Element

MFORX

SMISC

1 - 7
MFORY

SMISC

2 - 8
MFORZ

SMISC

3 - 9
MMOMZ

SMISC

6 - 12
TX

SMISC

13 19 25
TZ

SMISC

14 20 26
TXZ

SMISC

15 21 27
MX

SMISC

16 22 28
MZ

SMISC

17 23 29
MXZ

SMISC

18 24 30
P1

SMISC

31 - 32
P2

SMISC

35 - 36

Corner Location

1

2

3

4

TEMP

LBFE

1 2 3 4
Table 4.61-3a SHELL61 (KEYOPT(6)=3) Item and Sequence Numbers for the ETABLE and ESOL Commands

KEYOPT(6) = 3

Name

Item

I

IL1

IL2

IL3

J

Top

SM

LS

1 13 25 37 49
STHK

LS

2 14 26 38 50
SH

LS

3 15 27 39 51
SMH

LS

4 16 28 40 52
EPELM

LEPEL

1 13 25 37 49
EPELTHK

LEPEL

2 14 26 38 50
EPELH

LEPEL

3 15 27 39 51
EPELMH

LEPEL

4 16 28 40 52
EPTHM

LEPTH

1 13 25 37 49
EPTHTHK

LEPTH

2 14 26 38 50
EPTHH

LEPTH

3 15 27 39 51
EPTHMH

LEPTH

4 16 28 40 52
Mid

SM

LS

5 17 29 41 53
STHK

LS

6 18 30 42 54
SH

LS

7 19 31 43 55
SMH

LS

8 20 32 44 56
EPELM

LEPEL

5 17 29 41 53
EPELTHK

LEPEL

6 18 30 42 54
EPELH

LEPEL

7 19 31 43 55
EPELMH

LEPEL

8 20 32 44 56
EPTHM

LEPTH

5 17 29 41 53
EPTHTHK

LEPTH

6 18 30 42 54
EPTHH

LEPTH

7 19 31 43 55
EPTHMH

LEPTH

8 20 32 44 56
Bot

SM

LS

9 21 33 45 57
STHK

LS

10 22 34 46 58
SH

LS

11 23 35 47 59
SMH

LS

12 24 36 48 60
EPELM

LEPEL

9 21 33 45 57
EPELTHK

LEPEL

10 22 34 46 58
EPELH

LEPEL

11 23 35 47 59
EPELMH

LEPEL

12 24 36 48 60
EPTHM

LEPTH

9 21 33 45 57
EPTHTHK

LEPTH

10 22 34 46 58
EPTHH

LEPTH

11 23 35 47 59
EPTHMH

LEPTH

12 24 36 48 60
Element

MFORX

SMISC

1 - - - 7
MFORY

SMISC

2 - - - 8
MFORZ

SMISC

3 - - - 9
MMOMZ

SMISC

6 - - - 12
TX

SMISC

13 19 25 31 37
TZ

SMISC

14 20 26 32 38
TXZ

SMISC

15 21 27 33 39
MX

SMISC

16 22 28 34 40
MZ

SMISC

17 23 29 35 41
MXZ

SMISC

18 24 30 36 42
P1

SMISC

43 - - - 44
P2

SMISC

47 - - - 48

Corner Location

1

2

3

4

TEMP

LBFE

1 2 3 4
Table 4.61-3b SHELL61 (KEYOPT(6)=5) Item and Sequence Numbers for the ETABLE and ESOL Commands

KEYOPT(6) = 5

Name

Item

I

IL1

IL2

IL3

IL4

IL5

J

Top

SM

LS

1 13 25 37 49 61 73
STHK

LS

2 14 26 38 50 62 74
SH

LS

3 15 27 39 51 63 75
SMH

LS

4 16 28 40 52 64 76
EPELM

LEPEL

1 13 25 37 49 61 73
EPELTHK

LEPEL

2 14 26 38 50 62 74
EPELH

LEPEL

3 15 27 39 51 63 75
EPELMH

LEPEL

4 16 28 40 52 64 76
EPTHM

LEPTH

1 13 25 37 49 61 73
EPTHTHK

LEPTH

2 14 26 38 50 62 74
EPTHH

LEPTH

3 15 27 39 51 63 75
EPTHMH

LEPTH

4 16 28 40 52 64 76
Mid

SM

LS

5 17 29 41 53 65 77
STHK

LS

6 18 30 42 54 66 78
SH

LS

7 19 31 43 55 67 79
SMH

LS

8 20 32 44 56 68 80
EPELM

LEPEL

5 17 29 41 53 65 77
EPELTHK

LEPEL

6 18 30 42 54 66 78
EPELH

LEPEL

7 19 31 43 55 67 79
EPELMH

LEPEL

8 20 32 44 56 68 80
EPTHM

LEPTH

5 17 29 41 53 65 77
EPTHTHK

LEPTH

6 18 30 42 54 66 78
EPTHH

LEPTH

7 19 31 43 55 67 79
EPTHMH

LEPTH

8 20 32 44 56 68 80
Bot

SM

LS

9 21 33 45 57 69 81
STHK

LS

10 22 34 46 58 70 82
SH

LS

11 23 35 47 59 71 83
SMH

LS

12 24 36 48 60 72 84
EPELM

LEPEL

9 21 33 45 57 69 81
EPELTHK

LEPEL

10 22 34 46 58 70 82
EPELH

LEPEL

11 23 35 47 59 71 83
EPELMH

LEPEL

12 24 36 48 60 72 84
EPTHM

LEPTH

9 21 33 45 57 69 81
EPTHTHK

LEPTH

10 22 34 46 58 70 82
EPTHH

LEPTH

11 23 35 47 59 71 83
EPTHMH

LEPTH

12 24 36 48 60 72 84
Element

MFORX

SMISC

1 - - - - - 7
MFORY

SMISC

2 - - - - - 8
MFORZ

SMISC

3 - - - - - 9
MMOMZ

SMISC

6 - - - - - 12
TX

SMISC

13 19 25 31 37 43 49
TZ

SMISC

14 20 26 32 38 44 50
TXZ

SMISC

15 21 27 33 39 45 51
MX

SMISC

16 22 28 34 40 46 52
MZ

SMISC

17 23 29 35 41 47 53
MXZ

SMISC

18 24 30 36 42 48 54
P1

SMISC

55 - - - - - 56
P2

SMISC

59 - - - - - 60

Corner Location

1

2

3

4

TEMP

LBFE

1 2 3 4
Table 4.61-3c SHELL61 (KEYOPT(6)=7) Item and Sequence Numbers for the ETABLE and ESOL Commands

KEYOPT(6) = 7

Name

Item

I

IL1

IL2

IL3

IL4

IL5

IL6

IL7

J

Top

SM

LS

1 13 25 37 49 61 73 85 97
STHK

LS

2 14 26 38 50 62 74 86 98
SH

LS

3 15 27 39 51 63 75 87 99
SMH

LS

4 16 28 40 52 64 76 88 100
EPELM

LEPEL

1 13 25 37 49 61 73 85 97
EPELTHK

LEPEL

2 14 26 38 50 62 74 86 98
EPELH

LEPEL

3 15 27 39 51 63 75 87 99
EPELMH

LEPEL

4 16 28 40 52 64 76 88 100
EPTHM

LEPTH

1 13 25 37 49 61 73 85 97
EPTHTHK

LEPTH

2 14 26 38 50 62 74 86 98
EPTHH

LEPTH

3 15 27 39 51 63 75 87 99
EPTHMH

LEPTH

4 16 28 40 52 64 76 88 100
Mid

SM

LS

5 17 29 41 53 65 77 89 101
STHK

LS

6 18 30 42 54 66 78 90 102
SH

LS

7 19 31 43 55 67 79 91 103
SMH

LS

8 20 32 44 56 68 80 92 104
EPELM

LEPEL

5 17 29 41 53 65 77 89 101
EPELTHK

LEPEL

6 18 30 42 54 66 78 90 102
EPELH

LEPEL

7 19 31 43 55 67 79 91 103
EPELMH

LEPEL

8 20 32 44 56 68 80 92 104
EPTHM

LEPTH

5 17 29 41 53 65 77 89 101
EPTHTHK

LEPTH

6 18 30 42 54 66 78 90 102
EPTHH

LEPTH

7 19 31 43 55 67 79 91 103
EPTHMH

LEPTH

8 20 32 44 56 68 80 92 104
Bot

SM

LS

9 21 33 45 57 69 81 93 105
STHK

LS

10 22 34 46 58 70 82 94 106
SH

LS

11 23 35 47 59 71 83 95 107
SMH

LS

12 24 36 48 60 72 84 96 108
EPELM

LEPEL

9 21 33 45 57 69 81 93 105
EPELTHK

LEPEL

10 22 34 46 58 70 82 94 106
EPELH

LEPEL

11 23 35 47 59 71 83 95 107
EPELMH

LEPEL

12 24 36 48 60 72 84 96 108
EPTHM

LEPTH

9 21 33 45 57 69 81 93 105
EPTHTHK

LEPTH

10 22 34 46 58 70 82 94 106
EPTHH

LEPTH

11 23 35 47 59 71 83 95 107
EPTHMH

LEPTH

12 24 36 48 60 72 84 96 108
Element

MFORX

SMISC

1 - - - - - - - 7
MFORY

SMISC

2 - - - - - - - 8
MFORZ

SMISC

3 - - - - - - - 9
MMOMZ

SMISC

6 - - - - - - - 12
TX

SMISC

13 19 25 31 37 43 49 55 61
TZ

SMISC

14 20 26 32 38 44 50 56 62
TXZ

SMISC

15 21 27 33 39 45 51 57 63
MX

SMISC

16 22 28 34 40 46 52 58 64
MZ

SMISC

17 23 29 35 41 47 53 59 65
MXZ

SMISC

18 24 30 36 42 48 54 60 66
P1

SMISC

67 - - - - - - - 68
P2

SMISC

71 - - - - - - - 72

Corner Location

1

2

3

4

TEMP

LBFE

1 2 3 4
Table 4.61-3d SHELL61 (KEYOPT(6)=9) Item and Sequence Numbers for the ETABLE and ESOL Commands

KEYOPT(6) = 9

Label

Item

I

IL1

IL2

IL3

IL4

IL5

IL6

IL7

IL8

IL9

J

Top

SM

LS

1 13 25 37 49 61 73 85 97 109 121
STHK

LS

2 14 26 38 50 62 74 86 98 110 122
SH

LS

3 15 27 39 51 63 75 87 99 111 123
SMH

LS

4 16 28 40 52 64 76 88 100 112 124
EPELM

LEPEL

1 13 25 37 49 61 73 85 97 109 121
EPELTHK

LEPEL

2 14 26 38 50 62 74 86 98 110 122
EPELH

LEPEL

3 15 27 39 51 63 75 87 99 111 123
EPELMH

LEPEL

4 16 28 40 52 64 76 88 100 112 124
EPTHM

LEPTH

1 13 25 37 49 61 73 85 97 109 121
EPTHTHK

LEPTH

2 14 26 38 50 62 74 86 98 110 122
EPTHH

LEPTH

3 15 27 39 51 63 75 87 99 111 123
EPTHMH

LEPTH

4 16 28 40 52 64 76 88 100 112 124
Mid

SM

LS

5 17 29 41 53 65 77 89 101 113 125
STHK

LS

6 18 30 42 54 66 78 90 102 114 126
SH

LS

7 19 31 43 55 67 79 91 103 115 127
SMH

LS

8 20 32 44 56 68 80 92 104 116 128
EPELM

LEPEL

5 17 29 41 53 65 77 89 101 113 125
EPELTHK

LEPEL

6 18 30 42 54 66 78 90 102 114 126
EPELH

LEPEL

7 19 31 43 55 67 79 91 103 115 127
EPELMH

LEPEL

8 20 32 44 56 68 80 92 104 116 128
EPTHM

LEPTH

5 17 29 41 53 65 77 89 101 113 125
EPTHTHK

LEPTH

6 18 30 42 54 66 78 90 102 114 126
EPTHH

LEPTH

7 19 31 43 55 67 79 91 103 115 127
EPTHMH

LEPTH

8 20 32 44 56 68 80 92 104 116 128
Bot

SM

LS

9 21 33 45 57 69 81 93 105 117 129
STHK

LS

10 22 34 46 58 70 82 94 106 118 130
SH

LS

11 23 35 47 59 71 83 95 107 119 131
SMH

LS

12 24 36 48 60 72 84 96 108 120 132
EPELM

LEPEL

9 21 33 45 57 69 81 93 105 117 129
EPELTHK

LEPEL

10 22 34 46 58 70 82 94 106 118 130
EPELH

LEPEL

11 23 35 47 59 71 83 95 107 119 131
EPELMH

LEPEL

12 24 36 48 60 72 84 96 108 120 132
EPTHM

LEPTH

9 21 33 45 57 69 81 93 105 117 129
EPTHTHK

LEPTH

10 22 34 46 58 70 82 94 106 118 130
EPTHH

LEPTH

11 23 35 47 59 71 83 95 107 119 131
EPTHMH

LEPTH

12 24 36 48 60 72 84 96 108 120 132
Element

MFORX

SMISC

1 - - - - - - - - - 7
MFORY

SMISC

2 - - - - - - - - - 8
MFORZ

SMISC

3 - - - - - - - - - 9
MMOMZ

SMISC

6 - - - - - - - - - 12
TX

SMISC

13 19 25 31 37 43 49 55 61 67 73
TZ

SMISC

14 20 26 32 38 44 50 56 62 68 74
TXZ

SMISC

15 21 27 33 39 45 51 57 63 69 75
MX

SMISC

16 22 28 34 40 46 52 58 64 70 76
MZ

SMISC

17 23 29 35 41 47 53 59 65 71 77
MXZ

SMISC

18 24 30 36 42 48 54 60 66 72 78
P1

SMISC

79 - - - - - - - - - 80
P2

SMISC

83 - - - - - - - - - 84

Corner Location

1

2

3

4

TEMP

LBFE

1 2 3 4

4.61.3 Assumptions and Restrictions

The axisymmetric shell element must be defined in the global X-Y plane and must not have a zero length. Both ends must have nonnegative X coordinate values and the element must not lie along the global Y axis.

If the element has a constant thickness, only TK(I) need be defined. TK(I) must not be zero. The element thickness is assumed to vary linearly from node I to node J. Some thick shell effects have been included in the formulation of SHELL61 but it cannot be properly considered to be a thick shell element. If these effects are important, it is recommended to use PLANE25. The element assumes a linear elastic material. Post analysis superposition of results is valid only with other linear elastic solutions. Strain energy does not consider thermal effects. The element should not be used with the large deflection option. Also, the element may not be deactivated with the EKILL command. You can use only axisymmetric (MODE,0) loads to generate the stress state used for stress stiffened modal analyses using this element.

4.61.4 Product Restrictions

There are no product restrictions for this element.