4.59 PIPE59 Immersed Pipe or Cable

Figure 4.59-1 PIPE59 Immersed Pipe or Cable

4.59.1 Input Data

The element x-axis is oriented from node I toward node J. The element y-axis is automatically calculated to be parallel to the global X-Y plane. Several orientations are shown in Figure 4.59-1. For the case where the element is parallel to the global Z axis (or within a 0.01 percent slope of it), the element y axis is oriented parallel to the global Y axis (as shown). Input and output locations around the pipe circumference identified as being at 0° are located along the element y-axis, and similarly 90° is along the element z-axis.

Figure 4.59-2 Immersed Pipe

KEYOPT(1) may be used to convert the element to the cable option by deleting the bending stiffnesses. The nonlinear "slack" cable effect available in LINK10 is not included in this option. If the element is not "torque balanced," the twist-tension option may be used (KEYOPT(1) = 2). This option accounts for the twisting induced when a helically wound or armored structure is stretched. The KEYOPT(2) key allows a reduced mass matrix and load vector formulation (with rotational degrees of freedom terms deleted as described in Section 14.59 of the ANSYS Theory Reference). This formulation is useful for suppressing large deflections and improving bending stresses in long, slender members. It is also often used with the twist-tension pipe option for cable structures.

The description of the waves, the current, and the water density are input through the water motion table. The water motion table is associated with a material number and is explained in detail in Table 4.59-1b. If the water motion table is not input, no water is assumed to surround the pipe. Note that even though the word "water" is used to describe various input quantities, the quantities may actually be characteristic of any fluid. Alternate drag coefficient and temperature data may also be input through this table.

A summary of the element input is given in Table 4.59-1. A general description of element input is given in Section 2.1.

Table 4.59-1 PIPE59 Input Summary

Element Name	PIPE59
Nodes	I, J
Degrees of Freedom	UX, UY, UZ, ROTX, ROTY, ROTZ if KEYOPT (1) # 1, or UX, UY, UZ if KEYOPT(1) = 1
Real Constants	See Table 4.59-1a
Material Properties	EX, ALPX, PRXY or NUXY, DENS, GXY, GXZ, DAMP, VISC
Surface Loads	Pressures: 1-PINT, 2-PX, 3-PY, 4-PZ, 5-POUT
Body Loads	Temperatures: TOUT (I), TIN (I), TOUT (J), TIN (J) if KEYOPT(3)=0, or TAVG(I), T90 (I), T180 (I), TAVG (J), T90 (J), T180 (J) if KEYOPT(3)=1
Special Features	Stress stiffening, Large deflection, Birth and death
KEYOPT(1)	0 - Pipe option 1 - Cable option 2 - Pipe with twist-tension option
KEYOPT(2)	0 - Consistent mass matrix and load vector 1 - Reduced mass matrix and load vector
KEYOPT(3)	0 - Temperatures represent the through-wall gradient 1 - Temperatures represent the diametral gradient
KEYOPT(5)	Wave force modifications 0 - Waves act on elements at their actual location 1 - Elements are assumed to be at wave peak 2 - Upward vertical wave velocity acts on element 3 - Downward vertical wave velocity acts on element 4 - Elements are assumed to be at wave trough
KEYOPT(6)	0 - No printout of member forces or moments 2 - Print member forces and moments in the element coordinate system
KEYOPT(7)	0 - Basic element printout 1 - Additional hydrodynamic integration point printout
KEYOPT(9)	Used only with the PX, PY, and PZ transverse pressures 0 - Use only the normal component of pressure 1 - Use the full pressure (normal and shear components)

No	Name	Meaning
1	DO	Outside diameter (Do) of the pipe (Length).
2	TWALL	Wall thickness of the pipe (Length) (defaults to Do/2.0).
3	CD	Coefficient of normal drag (CD). May be overridden by Constants 43 through 54 of water motion table (See Table 4.59-1b).
4	CM	Coefficient of inertia (CM).
5	DENSO	Internal fluid density (used for pressure effect only)(Mass/Length3).
6	FSO	Z coordinate location of the free surface of the fluid on the inside of the pipe (used for pressure effect only). (See Figure 4.59-2.)
7	CENMPL	Mass per unit length of the internal fluid and additional hardware (used for mass matrix computation).
8	CI	Added-mass-used/added-mass for circular cross-section. CI defaults to 1.0 if input as zero. If CI is desired as 0.0 (suppression of added mass effects), CI must be input as any negative number.
9	CB	(Buoyancy-force-used)/(Buoyancy-force based on outside diameter and water density). CB defaults to 1.0 if input as zero. If CB is desired as 0.0 (suppression of buoyancy effects), CB must be input as any negative number.
10	CT	Coefficient of tangential drag (CT). May be overridden by Constants 55 through 66 of water motion table (See Table 4.59-1b).
11	ISTR	Initial strain in axial direction.
12	DENSIN	Density of external insulation1.
13	TKIN	Thickness of external insulation (ti).

1. Density of external insulation (_i).

The data listed in Table 4.59-1b is entered in the data table with the TB commands. If the table is not input, no water is assumed to surround the pipe. Constants not input are assumed to be zero. If the table is input, ACELZ must also have a positive value and remain constant for all load steps. The constant table is started by using the TB command (with Lab=WATER). Up to 196 constants may be defined with the TBDATA commands. The constants (C1-C196) entered on the TBDATA commands (6 per command) are:

Table 4.59-1b Water Motion Table

phi = , theta = , tau = , psi = , Psi =

Constant	Meaning
1-5	KWAVE	KCRC	DEPTH	DENSW	phi
7-12	Z(1)	W(1)	theta(1)	Z(2)	W(2)		theta(2)
13-18	Z(3)	W(3)	theta(3)	Z(4)	W(4)		theta(4)
19-24	Z(5)	W(5)	theta(5)	Z(6)	W(6)		theta(6)
25-30	Z(7)	W(7)	theta(7)	Z(8)	W(8)		theta(8)
31-36	Re(1)	Re(2)	Re(3)	Re(4)	Re(5)		Re(6)
37-42	Re(7)	Re(8)	Re(9)	Re(10)	Re(11)		Re(12)
43-48	CD(1)	CD(2)	CD(3)	CD(4)	CD(5)		CD(6)
49-54	CD(7)	CD(8)	CD(9)	CD(10)	CD(11)		CD(12)
55-60	CT(1)	CT(2)	CT(3)	CT(4)	CT(5)		CT(6)
61-66	CT(7)	CT(8)	CT(9)	CT(10)	CT(11)		CT(12)
67-72	T(1)	T(2)	T(3)	T(4)	T(5)		T(6)
73-74	T(7)	T(8)
79-82	A(1)	tau(1)	psi(1)	WL(1)
85-88	A(2)	tau(2)	psi(2)	WL(2) "	For KWAVE=0,1 or 2
					For KWAVE=2, use only A(1), tau(1), psi(1)
193-196	A(20)	tau(20)	psi(20)	WL(20)
79-81	X(1)/(H*T*G)	Not Used	Psi(1)
85-86	X(2)/(H*T*G)	DPT/LO
91-92	X(3)/(H*T*G)	L/LO
97-98	X(4)/(H*T*G)	H/DPT
103-104	X(5)/(H*T*G)	PSI/(G*H*T)		For KWAVE=3 (See Ref. (Dean)7 for definitions other than Psi)
109	X(6)/(H*T*G)
V	V
193	X(20)/(H*T*G)

where:

KWAVE = Wave selection key (see next section)

KCRC = Wave/current interaction key (see next section)

DEPTH = Depth of water to mud line (DEPTH > 0.0) (Length)

DENSW = Water density, _w, (DENSW > 0.0) (Mass/Length³)

= Wave direction (see Figure 4.59-2)

Z(j) = Z coordinate location of current measurement (see Figure 4.59-2) (location must be input starting at the ocean floor (Z(1)=-DEPTH) and ending at the water surface (Z(MAX)=0.0). If the current does not change with height, only W(1) needs to be defined.)

W(j) = Drift velocity of current at this location (Length/Time)

(j) = Direction of current at this location (Degrees) (see Figure 4.59-2)

Re(k) = Twelve Reynolds number values (if used, all 12 must be input in ascending order)

CD(k) = Twelve corresponding normal drag coefficients (if used, all 12 must be input)

CT(k) = Twelve corresponding tangential drag coefficients (if used, all 12 must be input)

T(j) = Temperature at Z(j) water depth (Degrees)

A(i) = Wave peak-to-trough height (0.0 A(i) < DEPTH) (Length)
(if KWAVE=2, A(1) is entire wave height and A(2) through A(5) are not used)

(i) = Wave period ((i) > 0.0) (Time/Cycle)

(i) = Adjustment for phase shift (Degrees)

WL(i) = Wave length (0.0 WL(i) < 1000.0*DEPTH) (Length)
(default
Use 0.0 with Stokes theory (KWAVE=2).

The Reynolds numbers are determined from the normal and tangential relative particle velocities, the pipe geometry, the water density, and the viscosity (input as VISC). The relative particle velocities include the effects of water motion due to waves and current, as well as motion of the pipe itself. If both Re(1) and CD(1) are positive, the value of C_D from the real constant table (Table 4.59-1a) is ignored and a log-log table based on Constants 31 through 54 of the water motion table (Table 4.59-1b) is used to determine C_D. If this capability is to be used, the viscosity, Re, and C_D constants must be input and none may be less than or equal to zero.

Similarly, if both Re(1) and CT(1) are positive, the value of C_T from the real constant table (Table 4.59-1a) is ignored, and a log-log table based on Constants 31 through 42 and 55 through 66 of the water motion table (Table 4.59-1b) is used to determine C_T. If this capability is to be used, the viscosity, Re, and C_T constants must be input and none may be less than or equal to zero.

Various wave theories may be selected with the KWAVE constant of the water motion table (Table 4.59-1b). These are:

• Small Amplitude Wave Theory with empirical modification of depth decay function (KWAVE=0)
• Small Amplitude Airy Wave Theory without modifications (KWAVE=1)
• Stokes Fifth Order Wave Theory (KWAVE=2)
• Stream Function Wave Theory (KWAVE=3).

Wave loading depends on the acceleration due to gravity (ACELZ), and it may not change between substeps or load steps. Therefore, when performing an analysis using load steps with multiple substeps, the gravity may only be "stepped on" [KBC,1] and not ramped. Since solution control may automatically ramp the load, issue KBC,1 after SOLCONTROL to generate the correct results.

With the stream function wave theory (KWAVE=3), the wave is described by alternate Constants 79 through 193 as shown in Table 4.59-1b. The definitions of the constants correspond exactly to those given in the tables of Dean (Reference 1 at the end of this section) for the forty cases of ratio of wave height and water depth to the deep water wave length. The other wave-related constants that the user inputs directly are the water density (DENSW), water depth (DEPTH), wave direction (), and acceleration due to gravity (ACELZ). The wave height, length, and period are inferred from the tables. The user should verify the input by comparing the interpreted results (the columns headed DIMENSIONLESS under the STREAM FUNCTION INPUT VALUES printout) with the data presented in the Ref. 1 tables. Note that this wave theory uses the current value defined for time [TIME] (which defaults to 1.0 for the first load step).

Several adjustments to the current profile are available with the KCRC constant of the water motion table as shown in Figure 4.59-3. The adjustments are usually used only when the wave amplitude is large relative to the water depth, such that there is significant wave/current interaction. Options include

1. use the current profile (as input) for wave locations below the mean water level and the top current profile value for wave locations above the mean water level (KCRC=0)

2. "stretch" (or compress) the current profile to the top of the wave (KCRC=1)

3. same as (2) but also adjust the current profile horizontally such that total flow continuity is maintained with the input profile (KCRC=2) (all current directions ((j)) must be the same for this option).

Figure 4.59-3 PIPE59 Velocity Profiles for Wave-Current Interactions

Element loads are described in Section 2.7. Pressures may be input as surface loads on the element faces as shown by the circled numbers on Figure 4.59-1. Internal pressure (PINT) and external pressure (POUT) are input as positive values. These pressures are in addition to the linearly varying pressure of the fluids on the inside and outside of the pipe. In handling the pressures, each element is assumed to be capped (i.e., have closed ends). The transverse pressures (PX, PY, and PZ) may represent wind or drag loads (per unit length of the pipe) and are defined in the global Cartesian directions. Positive transverse pressures act in the positive coordinate directions. The normal component or the projected full pressure may be used (KEYOPT(9)). See Section 14.16.7 of the ANSYS Theory Reference for more details.

Temperatures may be input as element body loads at the nodes. Temperatures may have wall gradients or diametral gradients (KEYOPT(3)). The first temperature at node I (TOUT(I) or TAVG(I)) defaults to TUNIF. If all temperatures after the first are unspecified, they default to the first. If all temperatures at node I are input, and all temperatures at node J are unspecified, the node J temperatures default to the corresponding node I temperatures. For any other input pattern, unspecified temperatures default to TUNIF. The average temperature is used in calculating the axial thermal growth.

Eight temperatures (T(j)) are read as Constants 67-74 corresponding to the eight water depths (Z(j)) input as Constants 7-30. These temperatures override any other temperature input (except TREF) unless the element is entirely out of the water or if all eight temperatures are input as zero. The thermal load vector from these temperatures may not be scaled in a superelement use pass if an expansion pass is to follow. Constants 31 through 66 may have zero values if desired. The temperatures input as Constants 67-74 are used to compute a temperature-dependent viscosity based on linear interpolation (if previous constants are not all zero). In the case of a solid cross-section (inside diameter = 0.0), they are also used to compute the material properties of the element.

For the mass matrix, the mass per unit length used for axial motion is the mass of the pipe wall (DENS), the external insulation (DENSIN), and the internal fluid together with the added mass of any additional hardware (CENMPL). The mass per unit length used for motion normal to the pipe is all of the above plus the added mass of the external fluid (DENSW).

CI should be 1.0 for a circular cross section. Values for other cross sections may be found in Ref. (McCormick)⁸. The user should remember, however, that other properties of PIPE59 are based on a circular cross section.

A summary of the element input is given in Table 4.59-1. A general description of element input is given in Section 2.1.

4.59.2 Output Data

• nodal displacements included in the overall nodal solution
• additional element output as shown in Table 4.59-2

The principal stresses are computed at the two points around the circumference where the bending stresses are at a maximum. The principal stresses and the stress intensity include the shear force stress component. The principal stresses and the stress intensity are based on the stresses at two extreme points on opposite sides of the neutral axis. If KEYOPT(6) = 2, the 12-member forces and moments (6 at each end) are also printed (in the element coordinate system).

The axial force (FX) excludes the hydrostatic force component, as does the MFORX member force (printed if KEYOPT(6)=2). If KWAVE=2 or 3 (Stokes or Stream Function theory), additional wave information is also printed. If KEYOPT(7)=1, detailed hydrodynamic information is printed at the immersed integration points. Angles listed in the output are measured () as shown in Figure 4.59-4. 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 4.59-4 PIPE59 Stress Output

The following notation is used in Table 4.59-2:

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 4.59-2 PIPE59 Element Output Definitions

Name	Definition	O	R
EL	Element number	Y	Y
NODES	Nodes - I, J	Y	Y
MAT	Material number	Y	Y
VOLU:	Volume	-	Y
CENT: X, Y, Z	Center location XC, YC, ZC	-	Y
LEN	Length	1	1
PRES	Pressures PINTE (average effective internal pressure), PX, PY, PZ, POUTE (average effective external pressure)	1	1
STH	Stress due to maximum thermal gradient through the wall thickness	1	1
SPR2	Hoop pressure stress for code calculations	-	1
SMI,SMJ	Moment stress at nodes I and J for code calculations	-	1
SDIR	Direct (axial) stress	-	1
SBEND	Maximum bending stress at outer surface	-	1
ST	Shear stress at outer surface due to torsion	-	1
SSF	Shear stress due to shear force	-	1
S(1MX, 3MN, INTMX, EQVMX)	Maximum principal stress, minimum principal stress, maximum stress intensity, maximum equivalent stress (all at the outer surface)	1	1
TEMP	Temperatures TOUT(I), TIN(I), TOUT(J), TIN(J)	2	2
TEMP	Temperatures TAVG(I), T90(I), T180(I), TAVG(J), T90(J), T180(J)	3	3
S(1, 3, INT, EQV)	Maximum principal stress, minimum principal stress, stress intensity, equivalent stress	4	4
S(AXL, RAD, H, XH)	Axial, radial, hoop, and shear stresses	4	4
EPEL(AXL, RAD, H, XH)	Axial, radial, hoop, and shear strains	4	4
EPTH(AXL, RAD, H)	Axial, radial, and hoop thermal strain	4	4
MFOR(X, Y, Z)	Member forces for nodes I and J (in the element coordinate system)	9	9
MMOM(X, Y, Z)	Member moments for nodes I and J (in the element coordinate system)	5	5
TEMP	TOUT(I), TOUT(J)	6	6
EPTHAXL	Axial thermal strains at nodes I and J	6	6
NODE	Node I or J	7	7
F(AXL)	Axial force (excludes the hydrostatic force)	7	7
SAXL	Axial stress (includes the hydrostatic stress)	7	7
SEQV	Equivalent stress (S:AXL minus the hydrostatic stress)	7	7
EPELAXL	Axial elastic strain (excludes the thermal strain)	7	7
NODE	Node I or J	8	8
F(AXL)	Axial force (excludes the hydrostatic force)	8	8
SAXL	Axial stress (includes the hydrostatic stress)	8	8
SH	Hoop stress	8	8
VR, VZ	Radial and vertical fluid particle velocities (VR is always > 0)	10	10
AR, AZ	Radial and vertical fluid particle accelerations	10	10
PHDYN	Dynamic fluid pressure head	10	10
ETA	Wave amplitude over integration point	10	10
TFLUID	Fluid temperature (printed if VISC is nonzero)	10	10
VISC	Viscosity	10	10
REN, RET	Normal and tangential Reynold's numbers (if VISC is nonzero)	10	10
CT, CD, CM	Input coefficients evaluated at Reynold's numbers	10	10
CTW, CDW	CT*DENSW*DO/2, CD*DENSW*DO/2	10	10
CMW	CM*DENSW*PI*DO**2/4	10	10
URT, URN	Tangential (parallel to element axis) and normal relative velocity	10	10
ABURN	Vector sum of normal (URN) velocities	10	10
AN	Accelerations normal to the element	10	10
FX, FY, FZ	Hydrodynamic forces tangential and normal to element axis	10	10
ARGU	Effective position of integration point (radians)	10	10

1. Output only for the pipe option (KEYOPT(1)=0 or 2)

2. If KEYOPT(3)=0

3. If KEYOPT(3)=1

4. Output only for the pipe option and the item repeats at 0,45,90,135,180,225,270,315° at node I, then at node J (all at the outer surface)

5. Output only for the pipe option (KEYOPT(1)=0 or 2) and if KEYOPT(6)=2

6. Output only for the cable option (KEYOPT(1)=1)

7. Output only for the cable option (KEYOPT(1)=1) and the inside diameter = 0.0

8. Output only for the cable option (KEYOPT(1)=1) and the inside diameter > 0.0

9. Output only if KEYOPT(6)=2

10. Hydrodynamic solution (if KEYOPT(7)=1 for immersed elements at integration points)

Table 4.59-3 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 4.59-3:

Name - output quantity as defined in the Table 4.59-2

Item - predetermined Item label for ETABLE command

E - sequence number for single-valued or constant element data

I,J - sequence number for data at nodes I and J

Node I
Name	Item	E	Circumferential Location
			0°	45°	90°	135°	180°	225°	270°	315°
SAXL	LS	-	1	5	9	13	17	21	25	29
SRAD	LS	-	2	6	10	14	18	22	26	30
SH	LS	-	3	7	11	15	19	23	27	31
SXH	LS	-	4	8	12	16	20	24	28	32
EPELAXL	LEPEL	-	1	5	9	13	17	21	25	29
EPELRAD	LEPEL	-	2	6	10	14	18	22	26	30
EPELH	LEPEL	-	3	7	11	15	19	23	27	31
EPELXH	LEPEL	-	4	8	12	16	20	24	28	32
EPTHAXL	LEPTH	-	1	5	9	13	17	21	25	29
EPTHRAD	LEPTH	-	2	6	10	14	18	22	26	30
EPTHH	LEPTH	-	3	7	11	15	19	23	27	31
MFORX	SMISC	1	-	-	-	-	-	-	-	-
MFORY	SMISC	2	-	-	-	-	-	-	-	-
MFORZ	SMISC	3	-	-	-	-	-	-	-	-
MMOMX	SMISC	4	-	-	-	-	-	-	-	-
MMOMY	SMISC	5	-	-	-	-	-	-	-	-
MMOMZ	SMISC	6	-	-	-	-	-	-	-	-
SDIR	SMISC	13	-	-	-	-	-	-	-	-
ST	SMISC	14	-	-	-	-	-	-	-	-
S1	NMISC	-	1	6	11	16	21	26	31	36
S3	NMISC	-	3	8	13	18	23	28	33	38
SINT	NMISC	-	4	9	14	19	24	29	34	39
SEQV	NMISC	-	5	10	15	20	25	30	35	40
SBEND	NMISC	88	-	-	-	-	-	-	-	-
SSF	NMISC	89	-	-	-	-	-	-	-	-
TOUT	LBFE	-	4	-	1	-	2	-	3	-
TIN	LBFE	-	8	-	5	-	6	-	7	-

Table 4.59-3a PIPE59 Item and Sequence Numbers for the ETABLE and ESOL Commands

Node J
Name	Item	E	Circumferential Location
			0°	45°	90°	135°	180°	225°	270°	315°
SAXL	LS	-	33	37	41	45	49	53	57	61
SRAD	LS	-	34	38	42	46	50	54	58	62
SH	LS	-	35	39	43	47	51	55	59	63
SXH	LS	-	36	40	44	48	52	56	60	64
EPELAXL	LEPEL	-	33	37	41	45	49	53	57	61
EPELRAD	LEPEL	-	34	38	42	46	50	54	58	62
EPELH	LEPEL	-	35	39	43	47	51	55	59	63
EPELXH	LEPEL	-	36	40	44	48	52	56	60	64
EPTHAXL	LEPTH	-	33	37	41	45	49	53	57	61
EPTHRAD	LEPTH	-	34	38	42	46	50	54	58	62
EPTHH	LEPTH	-	35	39	43	47	51	55	59	63
MFORX	SMISC	7	-	-	-	-	-	-	-	-
MFORY	SMISC	8	-	-	-	-	-	-	-	-
MFORZ	SMISC	9	-	-	-	-	-	-	-	-
MMOMX	SMISC	10	-	-	-	-	-	-	-	-
MMOMY	SMISC	11	-	-	-	-	-	-	-	-
MMOMZ	SMISC	12	-	-	-	-	-	-	-	-
SDIR	SMISC	15	-	-	-	-	-	-	-	-
ST	SMISC	16	-	-	-	-	-	-	-	-
S1	NMISC	-	41	46	51	56	61	66	71	76
S3	NMISC	-	43	48	53	58	63	68	73	78
SINT	NMISC	-	44	49	54	59	64	69	74	79
SEQV	NMISC	-	45	50	55	60	65	70	75	80
SBEND	NMISC	90	-	-	-	-	-	-	-	-
SSF	NMISC	91	-	-	-	-	-	-	-	-
TOUT	LBFE	-	12	-	9	-	10	-	11	-
TIN	LBFE	-	16	-	13	-	14	-	15	-

Table 4.59-3b PIPE59 Item and Sequence Numbers for the ETABLE and ESOL Commands

Name	Item	E
STH	SMISC	17
PINTE	SMISC	18
PX	SMISC	19
PY	SMISC	20
PZ	SMISC	21
POUTE	SMISC	22
SPR2	NMISC	81
SMI	NMISC	82
SMJ	NMISC	83
S1MX	NMISC	84
S3MN	NMISC	85
SINTMX	NMISC	86
SEQVMX	NMISC	87

Table 4.59-3c lists additional print and post data file output available through the ETABLE command if KEYOPT7=1.

Table 4.59-3c PIPE59 Item and Sequence Numbers for the ETABLE and ESOL Commands

Name	Item	E- First Integration Point	E- Second Integration Point
VR	NMISC	103	133
VZ	NMISC	104	134
AR	NMISC	105	135
AZ	NMISC	106	136
PHDY	NMISC	107	137
ETA	NMISC	108	138
TFLUID	NMISC	109	139
VISC	NMISC	110	140
REN	NMISC	111	141
RET	NMISC	112	142
CT	NMISC	113	143
CTW	NMISC	114	144
URT	NMISC	115	145
FX	NMISC	116	146
CD	NMISC	117	147
CDW	NMISC	118	148
URN	NMISC	119, 120	149, 150
ABURN	NMISC	121	151
FY	NMISC	122	152
CM	NMISC	123	153
CMW	NMISC	124	154
AN	NMISC	125, 126	155, 156
FZ	NMISC	127	157
ARGU	NMISC	128	158

4.59.3 Assumptions and Restrictions

If the element is used out of water, the water motion table (Table 4.59-1b) need not be included. The element should also be used with caution in the reduced transient dynamic analysis since this analysis type ignores the element load vector. Fluid damping, if any, should be handled via the hydrodynamic load vector rather than (mass matrix) damping.

The applied thermal gradient is assumed to be linear along the length of the element. The cable option does not consider "slack" cable effects. The same water motion table (Table 4.59-1b) should not be used for different wave theories in the same problem. The lumped mass matrix formulation [LUMPM,ON] is not allowed for PIPE59 when using "added mass" on the outside of the pipe (CI 0.0).

4.59.4 Product Restrictions