Relative deformation on path - Example

Pernelle Marone-Hitz
Pernelle Marone-Hitz Member, Moderator, Employee Posts: 715
First Comment First Anniversary Ansys Employee Solution Developer Community of Practice Member
edited June 2023 in Structures

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

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Answers

  • Pernelle Marone-Hitz
    Pernelle Marone-Hitz Member, Moderator, Employee Posts: 715
    First Comment First Anniversary Ansys Employee Solution Developer Community of Practice Member
    Answer ✓

    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))