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diff --git a/764/CH7/EX7.20.b/solution7_20.sce b/764/CH7/EX7.20.b/solution7_20.sce
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+
+function[] = plot_format()
+    //Get the handle of current axes
+    g = gca()
+    //Give labels and set label properties
+    g.labels_font_color=5
+    g.font_size=3
+    g.grid=[1,1]
+    g.box="off"
+endfunction
+
+//Obtain path of solution file
+path = get_absolute_file_path('solution7_20.sce')
+//Obtain path of data file
+datapath = path + filesep() + 'data7_20.sci'
+//Obtain path of function file
+funcpath = path + filesep() + 'functions7_20.sci'
+//Clear all
+clc
+//Execute the data file
+exec(datapath)
+exec(funcpath,[-1])
+//Calculate the endurance limit stress for bolt Sdash (N/mm2)
+Sdash = (50/100)*Sut
+//Calculate Ka, Kb and Kc
+[Ka, Kb, Kc] = fluctuate(op, d, reliability)
+//Calculate Kd 
+Kd = 1/Kf
+//Calculate the corrected endurance limit stress Se (N/mm2)
+Se = Kb * Kc * Kd * Sdash
+//Plot modified Goodman diagram
+//The common quadrilateral in the plot is the area of concern
+y1 = {Se 0}
+x1 = {0 Sut}
+y2 = {Syt 0}
+x2 = {0 Syt}
+plot(x1,y1,'--*')
+plot(x2,y2,'-*')
+plot_format()
+title('Modified Goodman diagram (Example 7.20)')
+xlabel('sigmaM (N/mm2)')
+ylabel('sigmaA (N/mm2)')
+//Calculate the angular velocity w (rad/s)
+w = (2 * %pi * n)/60
+//Calculate the crank radius r (m)
+r = (0.5 * l)/1000
+//Calculate the ratio of length of connecting rod to crank radius n1
+n1 = (c/(r * 1000))
+//Calculate the inertia force on bolt at normal running condition I (N)
+I = m * r * (w^2) * (cosd(theta) + (cosd(2 * theta)/n1))
+//Calculate the engine speed at overspeed condition nmax (rpm)
+nmax = n + ((load/100)*n)
+//Calculate the inertia force on bolt at overspeed Imax (N)
+Imax = m * r * (((2 * %pi * nmax)/60)^2) * (cosd(theta) + (cosd(2 * theta)/n1))
+//Calculate the force acting on each bolt under normal running condition P (N)
+P = I/N
+//Calculate the force acting on each bolt under overspeed condition PbMax (N)
+PbMax = Imax/N
+//Calculate the initial pre-load on the bolts Pi (N)
+Pi = PbMax/((kb + kc)/kc)
+//Calculate the maximum force in the bolt PMAX (N)
+PMAX = Pi + ((kb/(kb + kc))* P)
+//Calculate the minimum force in the bolt PMIN (N)
+PMIN = Pi
+//Calculate the mean force and force amplitude
+Pm = (PMAX + PMIN)/2
+Pa = (PMAX - PMIN)/2
+//Calculate the actual core cross-section area of the bolt A (mm2)
+A = (Pa + (Pi/((1 + (Sut/Se)) * fs)))/(Sut/((1 + (Sut/Se))*fs))
+//Choose proper diameter from Table 7.1
+//Print results
+printf('\nCore cross-section area of the bolt(A) = %f mm2\n',A)