Fig. 18: Comparison of envelope curves with different l and kφ = 0.002, Quadrature: 1 GP per subelement; centre crack: solid lines, shifted crack: dashed lines
 
Here, the upper values (envelope curves) of the point data of the numerical quadrature error e^int_Γlς (Eq. 58) of the crack surface integral (the max. expected error) with respect to the number of integration points is shown for different l/h (0.5,1,1.5). The phase-field is not numerically calculated by the means of FE but the stabilised phase-field is given (φς) as well as the analytical solution (φ). The solid lines refer to a given crack in the middle of the bar and the dashed lines refer to a given crack at a off-center position. 

for each file -> Columns
1: number of integration points 
2: error 

file fig_18_data_1.csv: l/h=0.5, centred crack (solid lines)
file fig_18_data_2.csv: l/h=1.0, centred crack (solid lines)
file fig_18_data_3.csv: l/h=1.5, centred crack (solid lines)

file fig_18_data_4.csv: l/h=0.5, shifted crack (dashed lines)
file fig_18_data_5.csv: l/h=1.0, shifted crack (dashed lines)
file fig_18_data_6.csv: l/h=1.5, shifted crack (dashed lines)