Relative deformation on path - Example

Pernelle Marone-Hitz · May 2022

User creates manually a directional or total deformation plot on a path:

The result curve is as follows:

They would like to extract the plot data values, create a linear interpolation between the first and last value and get the relative displacement as: relativeDef = extractedDef - linearRegressionDef

Pernelle Marone-Hitz · May 2022

Below script will do just that :

import wbjn
import units
import os

def GetLinearRegression(ps,pv):
    x1=ps[0]
    x2=ps[-1]
    y1=pv[0]
    y2=pv[-1]
    
    a=(y2-y1)/(x2-x1)
    b=y1-a*x1
    
    return a,b

def GetPathCurvAbscissa(px,py,pz):
    import math

    ps=[]
    # Retrieve curvilinear abscissa. Paths are straight lines, 
    # so retrieve length from end points
    
    length=sqrt((px[-1]-px[0])**2+(py[-1]-py[0])**2+(pz[-1]-pz[0])**2)
    # now get abscissa
    for i in range(len(px)):
        l=sqrt((px[i]-px[0])**2+(py[i]-py[0])**2+(pz[i]-pz[0])**2)
        ps.append(l)
    
    return ps,length

# Retrieve all deformation results
all_res=ExtAPI.DataModel.GetObjectsByType(DataModelObjectCategory.DeformationResult)



path_res=[]
# Check if results are scoped on a path
for res in all_res:
    if res.ScopingMethod==Ansys.Mechanical.DataModel.Enums.GeometryDefineByType.Path:
        if res.Suppressed==False:
            path_res.append(res)
        
if len(path_res)>0: # Results scoped on path have been found
    # Retrieve user_files folder
    cmd = 'returnValue(GetUserFilesDirectory())'
    user_dir = wbjn.ExecuteCommand(ExtAPI,cmd)
    
    # Write data to 'relative_path_data.csv' in project's user_files folder
    f=open(os.path.join(user_dir,'relative_path_data.csv'),'w')
    # Loop over results to find deformation results scoped on paths
    for res in path_res:
        pdata=res.PlotData.Values
        
        # Retrieve results unit and compute scale_factor to export in project units        
        currentLengthUnit=ExtAPI.DataModel.CurrentUnitFromQuantityName('Length')
        scale_factor=units.ConvertUnit(1.,pdata[3].Unit,currentLengthUnit)
        
        # Split in X, Y, Z and values
        pdata_X=[]
        pdata_Y=[]
        pdata_Z=[]
        pdata_Values=[]
        for i in range(pdata[3].Count):
            pdata_X.append(pdata[0][i]*scale_factor)
            pdata_Y.append(pdata[1][i]*scale_factor)
            pdata_Z.append(pdata[2][i]*scale_factor)
            pdata_Values.append(pdata[3][i]*scale_factor)
        # Compute curvilinear abscissa
        pdata_S,length=GetPathCurvAbscissa(pdata_X,pdata_Y,pdata_Z)
        # linear regression on path values
        a,b=GetLinearRegression(pdata_S,pdata_Values)
    
        # Write data to csv file with ',' as separator
        f.write('{0},\n'.format(res.Name))
        # Header
        f.write('{0} in {5},{1} in {5},{2} in {5},{3} in {5},{4} in {5}\n'.format('X Coord','Y Coord','Z Coord','Abscissa on path','Deformation',currentLengthUnit))
        # Values
        for i in range(len(pdata_Values)):
            # this is the deformation value minus the linear regression value
            relative_value=pdata_Values[i]-(a*pdata_S[i]+b)
            f.write('{0},{1},{2},{3},{4}\n'.format(pdata_X[i],pdata_Y[i],pdata_Z[i],pdata_S[i],relative_value))
        f.write('\n')    
    f.close()
else: # No results scoped on path, issue warning message
    ExtAPI.Application.Messages.Add(Ansys.Mechanical.Application.Message('No deformation results on path available.', MessageSeverityType.Warning))

Relative deformation on path - Example

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