Updating addCreep functionality:

- it can import properties of the line from lineProps.
- it checks for the properties of the line if it has a creep rate or not. if it does, we apply creep.
- if the user did not define a specific creep_percent, it will apply creep based on the creep rate with an assumed design life of 28 years (EoL).
- it also updates the line diameter as well depending on the stretch of the line (to keep nominal diameter the same).

Author: Yuksel-Rudy

famodel/mooring/mooring.py

@@ -1120,24 +1120,40 @@ def addCorrosion(self,corrosion_mm=10):
                 MBL_cor = sec['type']['MBL']
             sec['type']['MBL'] = MBL_cor
 
-    def addCreep(self, creep_precent=0.02):
+    def addCreep(self, lineProps, creep_percent=None):
         '''
         Elongates the polyester lines (if exists) in the mooring by a certain creep percentage
 
         Parameters
         ----------
-        creep_precent : float, optional
-            Percentage of creep elongation to add to polyester lines. The default is 0.02 (2%).
-
+        lineProps : dict
+            Dictionary of line properties from MoorProps yaml
+        creep_percent : float, optionals
+            Percentage of creep elongation to add to polyester lines. If not given, the creep rate from the lineProps dictionary will be used with a design life of 28.
         '''
+        design_life = 28 # years  - changeable later if needed
+
+        from moorpy.helpers import getLineProps
         if self.ss:
             for i, line in enumerate(self.ss.lineList):
-                if line.type['material']=='polyester':
-                    L_creep = line.L * (1 + creep_precent)
-                    self.setSectionLength(L_creep, i)
+                # check if the line type has a creep property in its MoorProps instead of checking for material name.
+                mat = line.type['material']
+                if mat not in lineProps:
+                    raise ValueError(f'Line material {mat} not found in lineProps dictionary.')
+                else:
+                    if lineProps[mat].get('creep_rate', False):
+                        if not creep_percent:
+                            creep_percent = lineProps[mat]['creep_rate'] * design_life  # total creep over design life
+                        L_creep = line.L * (1 + creep_percent)
+                        self.setSectionLength(L_creep, i)
+                        # Change the diameter size to account for creep thinning
+                    
+                        d_nom_creep = line.type['d_nom'] / np.sqrt(1 + creep_percent)
+                        lineType_creep = getLineProps(d_nom_creep, mat, lineProps)
+                        line.type = lineType_creep  # update line type with new diameter [not sure if that's what we need to do.]
         else:
             raise ValueError('Mooring subsystem must be created before adding creep.')
-            
+        
     def getEnvelope(self,ang_spacing=45,SFs=True):
         '''Computes the motion envelope of the Mooring based on the watch 
         circle(s) of what it's attached to. If those aren't already 

famodel/project.py

@@ -3534,22 +3534,25 @@ def getCorrosion(self,corr_th=10,lines='all'):
         for ii,i in enumerate(idx):
             self.mooringList[i].addCorrosion(corrosion_mm=corr_th)
 
-    def addCreep(self, creep_precent=0.02):
+    def addCreep(self, lineProps=None, creep_percent=None):
         '''
         Function to add creep to all mooring lines in the project
 
         Parameters
         ----------
-        creep_precent : float, optional
-            Percentage of line length to add as creep. The default is 0.02 (2%).
+        creep_percent : float, optional
+            Percentage of line length to add as creep. If not given, the creep rate from the lineProps dictionary will be used with a design life of 28.
 
         Returns
         -------
         None.
 
         '''
+        if lineProps is None:
+            lineProps = self.ms.lineProps
         for moor in self.mooringList.values():
-            moor.addCreep(creep_precent=creep_precent)
+            moor.addCreep(lineProps=lineProps, creep_percent=creep_percent)
+                
 
     def updateUniformArray(self,n_rows,pf_rows,spacingXY,grid_rotang=0,grid_skew_x=0,grid_skew_y=0,grid_trans_x=0,grid_trans_y=0,phis=[0,0],center=[0,0]):
         '''