This template is used in conjunction with a set of macros and comi files to automate the analyses of installing a jacket, deck or other structure. In general, they can be used for loadout, transportation, lift, upend and launch. Considerable flexibility has been incorporated into this system so that most cases can be easily considered. This system has been designed so that several simulations that represent difference phases of a structure can be performed, load cases generated, and one code check over all load cases can be produced.

Most of the data required is defined in this file. The exceptions are the basic model data of the structures to be analyzed and the barge data. The structures data is assumed to be in other files which are inserted. The barge data is also inserted, but it is assumed to be in a special directory which contains all of the barge models.

Basic Data

The data required here is broken down into sections. The first section contains "basic" data required for any analysis and is basically self explanatory. The line

     &DIMEN -SAVE -DIMEN METERS K-NTS

defines the units which will be used in the analysis. Two definitions are available to control the pictures:

     I_SET DO_MOVIE     .TRUE.

and

     I_SET RENDER     -RENDER GL

The if the first of these is set .TRUE. then "movies" of and launch and or upending will be created provided you are rendering the pictures with GL. The second one defines the rendering mode of the pictures. If -RENDER GL is set, then pictures will be rendered with GL. To save time, you could use -RENDER WF. Finally, if you are using a "TERMINAL" interface, all pictures will be rendered as WF pictures and no movies will be produced.

The following:

     I_SET WDEPTH     390

defines the water depth. The "margins", or weight contingencies are defined by the two lines:

     I_SET MARGIN         5

     I_SET PER_APPLY    105

The first of these is for the basic steel in the model and the next is for any "joint loads".

The line

     I_SET CODE_LIM   1.33,1e6  1.,1.33  0.9,1.0  0.,0.9

defines the limits for the code check and joint check reports. If you do not change this line, then the checks will be broken down ratios between 1. and 1.33, the next for ratios between .9 and 1, and the last for ratios between 0 and .9.

The elements for which code checks and/or fatigue will be performed are defined by the following:

     I_SET C_CODE   -SELE @ -EX ~dum@

     I_SET N_CODE   -SELE @ -EX

     I_SET N_FAT    -SELE @ -EX

Here, CLASS defines a variable that is used to determine the classes which will be considered for all three categories. If a class is not defined here, no element in this class will be considered for Beam Check, Joint Check, or Joint Fatigue. N_CODE is a variable which defines the joints which will be considered. If a joint is not selected, no results for Joint Check or Joint Crushing will be produced for this joint. Finally, N_FAT defines the joint to be considered for Joint fatigue.

Fatigue Data

If one wants to consider fatigue, then he must define several things, the first of which is essential. A file containing the data for the tow duration must be defined with the line:

     I_SET ENVDAT     "file"

Also, one may wish to alter one or more of the following:

     I_SET FAT_LIM  1.,1.e6 0.25,1 0,0.25

     I_SET SCF      Efthymiou

     I_SET SN       XP

     I_SET B_SN     AWSE

The first of these defines the limits for which the fatigue reports will be broken down. If this is not changed, one will receive 3 reports for joint and beam fatigue: The first will have CDRs above 1, the second will have CDRs between .25 and 1, and the last will have CDRs between 0 and .25. The next two lines deal with tubular joint fatigue. Here, SCF defines the type of SCFs which will be computed during fatigue. The SN variable defines the SN curve for Joint Fatigue. In either of the variables, multiple curves can be used. For example,

     I_SET SN       = XP X

will produce fatigue results for both the XP and the X curves. The B_SN variable defines the SN curve which will be used for Beam Fatigue, and the &REP_SELECT command defines a new type of SN curve, AWSE. Here, the default SCFs for beam which are not tubes are set to 1, and the AWS E curve is used for beam fatigue.

Report Data

The following command defines the cover page for the report. Be sure to inclose the variables in single quotes(') if they are more than one word.

     I_BEGIN,  -OPTIONS

And the available options are:

     -TLINE1, 'XYZ EXPLORATION and PRODUCTION'

     -TLINE2, '8 Pile Jacket for the COWABUNGA Field'

     -TLINE3, 'Installed Offshore Timbuktu'

     -CLIENT, 'QRS Engineering, Inc'

     -FOOTER, '8 Leg Jacket'

Barge Data

This data is necessary only for a launch or transportation.

     USE_VES BARGE

The data for the barge being used is more restrictive than that for the structure. The reason for this is that the barge tilt beam data and many other things are necessary. Thus, the barge used must be one of the barges supplied, or a new barge defined in the same format. Here, BARGE, should be the name of the barge one wishes to use.

Structure Data

This section of data needs to be completed for any analysis. Here, one is calling a macro which sets up the data required for each structure to be analyzed. The syntax of the macro is:

     MODEL_IN NAME FILE X Y Z -OPTIONS

And the available options are:

     -ORIENT, *O1, *O2, *O3

     -PORT_NOD, *P1, *P2, *P3 ...

     -STBD_NOD, *S1, *S2, *S3 ...

     -TOP_NODE, *TOP_NODE

     -EXTREMES, PNAM1, *PNOD1, PNAM2, *PNOD2 ...

The variable "FILE" defines the file which contains the model for the structure.

If you have a transportation analysis with multiple structures, you should have a "MODEL_IN" for each structure. Sometimes you may have a jacket and deck on the same barge, or two deck sections on the same barge. The MODEL_IN command can also be used to input files that describe miscellaneous cargo, such as piles or boat landings. In this case, FILE for each cargo would contain the appropriate commands to adequately describe the cargo, such as PGEN and #WEIGHT.

The variable "NAME" defines the type of structure. Any name up to eight characters may be used, but the names JACKET and TRIPOD are special. Also, for multiple structures on one barge, the first three characters of the name must be unique. This definition controls the type of connections which are established for transportation and the initial setup for upending. For upending with a type of TRIPOD, the axes system will not be moved when slings are added.

The variables X, Y and Z define the location of the "origin" of the structure on the barge. Here, X is the location aft of the bow, Y the distance off of the centerline and Z is the height above the barge deck. The meaning of origin changes with how the structure is oriented. Normally, the two options -PORT_NOD and -STBD_NOD define the orientation. If they orient the body, the origin is the midpoint of the trailing port and starboard nodes. If the -ORIENT option is used, the origin is the first node specified.

The two options -PORT_NOD and -STBD_NOD are used to define the names of the nodes on the "launch legs". The first node for each variable is the node at the leading edge of the jacket and the last is the node at the trailing edge of the jacket. The leading edge is defined as the end of the jacket that enters the water first. The PORT_NODes are on the port side of the barge while the STBD_NODes are on the starboard side. When specified, these nodes define the orientation of the structure on the barge. They are also used to define barge/structure connections if a V_LWAY connection is specified or if one preforms a loadout analysis.

For a structure which is not symmetrical about the barge centerline the orientation scheme is different. Here, the -ORIENT option is used. This option defines three nodes. The first node is where distances for positioning will be measured and is normally at the bottom of the leg that is parallel with the deck edge, assuming the top of jacket faces aft. The second node is along the leg from the first node, and the third node is on the other side of the barge, usually along the horizontal level in line with the first node. Y is the distance from the centerline of the barge to the first node, positive towards starboard. Note that if one specifies starboard nodes and a negative Y then the jacket will be placed under the barge.

TOP_NOD is used for an initial guess during upending and stability springs for other types of analysis. This node should be on the face of the structure which is the highest above the water in the initial floating position and should not be attached to any slings.

Points used for reporting purposes can be specified with the -EXTREME option. Here, a point name and node name is required for each point of interest. For a jacket, these are normally the top and bottom nodes of each corner leg.

For deep water fixed leg structures, the inside diameter of leg compartments can vary substantially. For these situations, there is a useful command for defining very accurate tank definitions, which has the following syntax:

     I_TANK TANK_NAM, *BOT_NOD, *TOP_NOD, E_BOT, E_TOP, -OPTIONS

And the available options are:

     -F_VALVE, VF_DIA, VF_DIST

     -V_VALVE, VV_DIA, VV_DIST

     -ELEVATION

     -PERMEABILITY, PERM

Here, TANK_NAM is the name given to the tank, and *BOT_NOD and *TOP_NOD are the names of the bottom and top nodes on the jacket leg where the tank resides. The variables E_BOT and E_TOP provide the locations of the bottom and top of the tank, respectively. These are the bulkhead locations inside the leg. If this information is not supplied, the bulkhead locations will be assumed to be at the bottom and top nodes. If the -ELEVATION option is used, these bulkhead locations will be assumed to be jacket elevations, where the jacket origin is at the inplace waterline, and Z is vertical up. Without this option, the bulkhead locations are assumed to be the length along the leg from the bottom node. Bulkhead locations are specified in feet or meters, depending on the current units. The diameter and location of the flood and vent valves are specified with the -F_VALVE and -V_VALVE options. For this information, valve diameter is specified in inches or millimeters, and the valve location is specified in feet or meters. The valve locations here are according to the use of -ELEVATION. If no valve information is provided, a 4 inch flood valve will be located at the bottom node, while a 4 inch vent valve will be placed at the top node. The -PERMEABILITY option allows one to specify the permeability for the tank. The I_TANK command will use the jacket model to prepare the proper TUBTANK definitions, capturing all the changes to inside diameter along the elements defining a jacket leg, including changes to segments in the elements.

Connector Data

There are 3 different categories of connectors that can be defined for use in a simulation: SLINGS, TIEDOWN CONNECTORS and VERTICAL SUPPORTS. Each of these categories uses the I_CONNECTOR command, followed by a type description and then the required data.

To define an upending sling assembly for use in a jacket upending analysis, a type of UP_SLING is used, and has the following syntax:

     I_CONNECTOR UP_SLING *U1 L1 *U2 L2 ...

The data that follows the connector type is a set of node names and harness lengths in feet or meters. The number of pairs defined gives the number of sling elements which will be attached. For a body name of JACKET, the order of the nodes is used to define the local body system. The origin of this system is the midpoint of the vector connecting the first two sling nodes. The local Y axis is in the direction of the first node toward the second, the local Z axis is from the second node to the third and the local X axis is given by the right hand rule.

To perform a lift analysis, you will need a connector type of LIFT_SLING:

     I_CONNECTOR LIFT_SLNG *L1 LEN1 *L2 LEN2 *L3 LEN3 *L4 LEN4

A sling will be constructed from each of the nodes specified to the common hook point.

Tiedown connectors for a transportation analysis can be defined using the following I_CONNECTOR types:

     I_CONNECTOR 4_TIE    ~TD_CLAS   *TIE1 *TIE2 ...

     I_CONNECTOR V_BRACE  ~TD_CLAS   *TIE1 *TIE2 ...

     I_CONNECTOR P_BRACE  ~TD_CLAS   *TIE1 *TIE2 ...

     I_CONNECTOR H_BRACE  ~TD_CLAS   *TIE1 *TIE2 ...

     I_CONNECTOR PCONNECT TIEDOWN DATA

     I_CONNECTOR XY_DELTA ~TD_CLASS DELTA_X DELTA_Y *TIE1 *TIE2 ...

When the 4_TIE connector type is specified, 4 tiedowns with the properties of ~TD_CLAS will be generated at each node specified. The ~TD_CLAS must be defined before it is referenced on the I_CONNECTOR 4_TIE command. The tiedowns will be arranged in star pattern, with each tiedown 45 degrees from a longitudinal axis that passes through the tiedown node and is parallel to the barge centerline. The longitudinal and transverse distance from the referenced structure node to the deck end of the tiedown is the same as the vertical distance of the referenced node above the barge deck.

Connectors types of V_BRACE, P_BRACE and H_BRACE are all very similar to one another. The names here refer to Vertical Brace, Pitch Brace, and Horizontal Brace, respectively. The V_BRACE takes only dynamic vertical load, no gravity load, and creates an element from the referenced node to the barge deck. The P_BRACE takes only longitudinal dynamic load, and creates a horizontal element that is 5 feet or meters long. The H_BRACE takes only transverse dynamic load, and creates a horizontal element from the referenced node to the side shell. As with the 4_TIE type, the referenced ~TD_CLAS must have been previously defined. For all these tiedown types, the connection at the barge end of the tiedown takes no moments, meaning a pinned connection.

If none of the above tiedown connector types are suitable, one can still define connectors explicitly, and place this definition in this file. For tiedowns, this is done with the ICONNECTOR PCONNECT command. While this format allows for any valid PCONNECT data, the following information is normally provided:

     I_CONNECTOR  PCONNECT dx dy dz ~tdclass *nod *b@

For structure descriptions that include tiedowns, the tiedowns should be removed from the structure file and placed in this file using the above I_CONNECTOR PCONNECT method.

The I_CONNECTOR XY_DELTA command provides an easy way to define tiedowns where the barge end remains at the same height as the referenced node on the structure. DELTA_X and DELTA_Y refer to the distance from the referenced node to the barge end of the tiedown.

Vertical supports that take gravity load can be defined with these I_CONNECTOR types:

     I_CONNECTOR V_LWAY

     I_CONNECTOR V_CAN  ~CAN_CLA  *C1 *C2 ...

     I_CONNECTOR V_REST ~REST_CL  *R1 *R2 ...

The V_LWAY type will create a vertical connector using the node names provided on the -PORT_NOD and -STBD_NOD options of MODEL_IN. This will actually create a structural element that simulates the launchway on a barge, using the launchway information provided in the barge model. If this launchway information is not available, a WBOX beam is generated that is 48 inches deep, 48 inches wide, with 1 inch plates for the flanges and sides, and 2 inch plate for the center plate. The connections created here are gap elements. For spectral load cases, only a linear structural solution can be performed, so the gap elements have no effect on these cases. For time domain load cases, a nonlinear structural solution is performed, which involves iteration over the support nodes to release those supports that show tension.

The connector type V_CAN provides a vertical support can with the properties provided by the can class ~CAN_CLA. A beam element is created from the referenced node to the barge deck, with moments about the local Y and Z axes released at barge end.

A connector type of V_REST works in a similar fashion. Here, simply specify the restraint class and support nodes, and restraints will be provided at each node.