Provided by: gmt-common_5.4.3+dfsg-1_all bug


       gmtflexure - Compute flexural deformation of 2-D loads, forces, bending and moments


       gmtflexure  -Drm/rl[/ri]/rw -ETe[u]|D|file [  -A[l|r][/args] ] [  -CpPoisson ] [  -CyYoung
       ] [  -Fforce ] [  -Qargs] [  -S ] [  -Twfile] [  -V[level] ] [  -Wwd] [  -Zzm] [ -bibinary
       ] [ -dnodata ] [ -eregexp ] [ -hheaders ] [ -iflags ] [ -oflags ]

       Note: No space is allowed between the option flag and the associated arguments.


       gmtflexure  computes  the  flexural response to 2-D loads using a range of user-selectable
       options, such as boundary conditions, pre-existing  deformations,  variable  rigidity  and
       restoring   force,   and  more.   The  solutions  are  obtained  using  finite  difference
       approximations to the differential equations.


              Sets density for mantle, load, infill (optionally, otherwise it is assumed to equal
              the load density), and water.  If ri is not given then it defaults to rl.

              Sets  the  elastic  plate  thickness  (in  meter); append k for km.  If the elastic
              thickness exceeds 1e10 it will be interpreted as a flexural rigidity D instead  (by
              default  D  is  computed  from  Te, Young’s modulus, and Poisson’s ratio; see -C to
              change these values).  Alternatively, supply a file with variable plate thicknesses
              or rigidities.  The file must be co-registered with any file given via -Q.


              Sets  the boundary conditions at the left and right boundary.  The bc can be one of
              four codes: 0 selects the infinity condition, were  both  the  deflection  and  its
              slope  are  set to zero.  1 selects the periodic condition where both the first and
              third derivatives of the deflection  are  set  to  zero.   2  selects  the  clamped
              condition  where  args  (if  given)  sets  the  deflection value [0] (and its first
              derivative is set to zero), while 3 selects the free condition where args is  given
              as  moment/force  which  specify  the  end  bending moment and vertical shear force
              [0/0].  Use SI units for any optional arguments.

              Change the current value of Poisson’s ratio [0.25].

              Change the current value of Young’s modulus [7.0e10 N/m^2].

              Set a constant horizontal in-plane force, in Pa m [0]

              Sets the vertical load specification. Choose among these three options:  -Qn  means
              there  is  no  input  load  file  and  that any deformation is simply driven by the
              boundary conditions set via -A.  If no rigidity or elastic thickness file is  given
              via -E then you must also append min/max/inc to initiate the locations used for the
              calculations.   Append  +  to  inc  to  indicate  the  number  of  points  instead.
              -Qq[loadfile]  is  a  file  (or  stdin  if  not  given) with (x,load in Pa) for all
              equidistant data locations.  Finally, -Qt[topofile] is a  file  (or  stdin  if  not
              given) with (x,load in m or km, positive up); see -M for topography unit used [m].

       -S     Compute  the  curvature  along  with  the deflections and report them via the third
              output column [none].

              Supply a file with pre-existing deformations [undeformed surface].

       -Wwd   Specify water depth in m; append k for km.  Must be positive  [0].   Any  subaerial
              topography  will be scaled via the densities set in -D to compensate for the larger
              density contrast with air.

       -Zzm   Specify reference depth to flexed surface in m; append k for km.  Must be  positive
              [0].  We add this value to the flexed surface before output.

       -V[level] (more …)
              Select verbosity level [c].

       -bi[ncols][t] (more …)
              Select native binary input.

       -d[i|o]nodata (more …)
              Replace input columns that equal nodata with NaN and do the reverse on output.

       -e[~]”pattern” | -e[~]/regexp/[i] (more …)
              Only accept data records that match the given pattern.

       -h[i|o][n][+c][+d][+rremark][+rtitle] (more …)
              Skip or produce header record(s).

       -icols[+l][+sscale][+ooffset][,] (more …)
              Select input columns and transformations (0 is first column).

       -ocols[,…] (more …)
              Select output columns (0 is first column).

       -^ or just -
              Print a short message about the syntax of the command, then exits (NOTE: on Windows
              just use -).

       -+ or just +
              Print  an  extensive  usage  (help)  message,  including  the  explanation  of  any
              module-specific option (but not the GMT common options), then exits.

       -? or no arguments
              Print  a  complete  usage (help) message, including the explanation of all options,
              then exits.


       The -M option controls the units used in all input and output files.  However, this option
       does  not  control  values given on the command line to the -E, -W, and -Z options.  These
       are assumed to be in meters unless an optional k for km is appended.


       We solve for plate flexure using a finite difference approach. This method can accommodate
       situations such as variable rigidity, restoring force that depends on the deflection being
       positive or negative, pre-existing deformation, and different boundary conditions.


       To compute elastic plate flexure from the topography load in topo.txt, for a 10  km  thick
       plate with typical densities, try

              gmt flexure -Qttopo.txt -E10k -D2700/3300/1035 > flex.txt



       gmt, gravfft, grdflexure, grdmath


       2018, P. Wessel, W. H. F. Smith, R. Scharroo, J. Luis, and F. Wobbe