1. Distance time series calculated from the time domain analyses

This option is mainly to be used in order to perform a check of collision risk between two risers, between a riser and the vessel or between a riser and a fixed structure. The minimum distance is calculated for only a part of the riser. All elements within the specified segments are searched to find this minimum distance at each time step.

Note that the distances are absolute, they are always positive values. The program cannot identify a line crossing situation.

1.1. Data group identifier, one input line

DISTance TIME SERIes        Plot

1.2. Output options, one input line

IOP IT1 NTS IDITYP IMETH IVES XCGVES YCGVES ZCGVES

  • IOP: integer: Code for type of output

    • IOP=1: Time series

    • IOP=2: Time series statistics

    • IOP=3: Spectral analysis

  • IT1: integer: First stored time step to be included

  • NTS: integer: No of stored time steps to be included (from IT1).

    • A large number includes the remaining time steps

  • IDITYP: integer: Type of distance to be calculated

    • IDITYP=1: Distance between specified segments on lines

    • IDITYP=2: Distance between specified segments on a line and a globally fixed line

    • IDITYP=3: Distance between specified segments on a line and a line fixed on the vessel

  • IMETH: integer, default: 1: Method option

    • IMETH=1: Distance between elements are calculated

    • IMETH=2: Distance between nodes are calculated

  • IVES: integer, default: 1: Vessel number in case of multivessel analysis and IDITYP = 3

  • XCGVES: real, default: 0: Static X coordinate of the vessel in case of IDITYP = 3

  • YCGVES: real, default: 0: Static Y coordinate of the vessel in case of IDITYP = 3

  • ZCGVES: real, default: 0: Static Z coordinate of the vessel in case of IDITYP = 3

With the distance, we here mean the minimum distance. All elements within the specified segment(s) are scanned for each time step in order to find the one with the minimum distance.

Method 1 is more accurate, but more time consuming than method 2.

1.3. Specification of segments on lines which the minimum distance should be calculated from, one input line

LINE-ID NSEG ISEG1 ISEG2 . . ISEG(NSEG)

  • LINE-ID: character(8): Line identifier

  • NSEG: integer/character: No of segments for which the minimum distances are to be calculated from

    • You may specify ALL in order to include all segments

  • ISEG: integer: The included segment numbers

Searching through all elements may cause rather large computation time.

1.4. Specified segments to which the minimum distance are calculated, to be given only if IDITYP=1. One input line

LINE-ID NSEG ISEG1 ISEG2 ... ISEG(NSEG)

  • LINE-ID: character(8): Line identifier

  • NSEG: integer/character: No of segments for which the minimum distances are to be calculated to

    • You may specify ALL in order to include all segments

  • ISEGj: integer: The included segment numbers

Searching through all elements may cause rather large computation time.

1.5. Specification of a line in the global coordinate system to which the minimum distance are to be calculated, to be given only if IDITYP=2. One input line

XG1 YG1 ZG1 XG2 YG2 ZG2

  • XG1: real: Global x-coordinate, end 1

  • YG1: real: Global y-coordinate, end 1

  • ZG1: real: Global z-coordinate, end 1

  • XG2: real: Global x-coordinate, end 2

  • YG2: real: Global y-coordinate, end 2

  • ZG2: real: Global z-coordinate, end 2

1.6. Specification of a line in the global coordinate system relative to the vessel reference point to which the minimum distance are to be calculated, to be given only if IDITYP=3

XV1 YV1 ZV1 XV2 YV2 ZV2

  • XV1: real: Vessel x-coordinate, end 1

  • YV1: real: Vessel y-coordinate, end 1

  • ZV1: real: Vessel z-coordinate, end 1

  • XV2: real: Vessel x-coordinate, end 2

  • YV2: real: Vessel y-coordinate, end 2

  • ZV2: real: Vessel z-coordinate, end 2

1.7. Options for the output distribution functions of the distance time series statistics, one input line

This input line is given only if IOP=2.

NCL XCMIN XCMAX

  • NCL: integer: No of classes in the output distribution functions (i.e. no of points on the abscissa axis)

    • 0<NCL<41

  • XCMIN: real: Range of argument values for output distribution functions is XCMIN*sx(1) - XCMAX*sx(1) in which sx(1) is the standard deviation of x estimated from the first sequence

  • XCMAX: real:

1.8. Spectrum smoothing parameter for the spectral analysis of the distance time series, one input line

This input line is given only if IOP=3.

MSM

  • MSM: integer, default: 0: Smoothing parameter

    • MSM=0: No smoothing

    • MSM>0: Smoothing by averaging over 2*MSM+1 values