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| author | priyanka | 2015-06-24 15:03:17 +0530 |
|---|---|---|
| committer | priyanka | 2015-06-24 15:03:17 +0530 |
| commit | b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b (patch) | |
| tree | ab291cffc65280e58ac82470ba63fbcca7805165 /764/CH7/EX7.20.b | |
| download | Scilab-TBC-Uploads-b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b.tar.gz Scilab-TBC-Uploads-b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b.tar.bz2 Scilab-TBC-Uploads-b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b.zip | |
initial commit / add all books
Diffstat (limited to '764/CH7/EX7.20.b')
| -rwxr-xr-x | 764/CH7/EX7.20.b/graph7_20.png | bin | 0 -> 14216 bytes | |||
| -rwxr-xr-x | 764/CH7/EX7.20.b/result7_20.txt | 119 | ||||
| -rwxr-xr-x | 764/CH7/EX7.20.b/solution7_20.sce | 72 |
3 files changed, 191 insertions, 0 deletions
diff --git a/764/CH7/EX7.20.b/graph7_20.png b/764/CH7/EX7.20.b/graph7_20.png Binary files differnew file mode 100755 index 000000000..7ccdd426e --- /dev/null +++ b/764/CH7/EX7.20.b/graph7_20.png diff --git a/764/CH7/EX7.20.b/result7_20.txt b/764/CH7/EX7.20.b/result7_20.txt new file mode 100755 index 000000000..e581160f8 --- /dev/null +++ b/764/CH7/EX7.20.b/result7_20.txt @@ -0,0 +1,119 @@ +-->//(Threaded Joints) Example 7.20
+
+-->//Number of bolts N
+
+-->N = 2
+ N =
+
+ 2.
+
+-->//Engine speed n (rpm)
+
+-->n = 2000
+ n =
+
+ 2000.
+
+-->//Length of stroke l (mm)
+
+-->l = 100
+ l =
+
+ 100.
+
+-->//Length of connecting rod c (mm)
+
+-->c = 200
+ c =
+
+ 200.
+
+-->//Mass of reciprocating parts m (kg)
+
+-->m = 5
+ m =
+
+ 5.
+
+-->//Overload percentage load (%)
+
+-->load = 50
+ load =
+
+ 50.
+
+-->//Assume the stiffness of the bolts to be 1N/mm kb
+
+-->kb = 1
+ kb =
+
+ 1.
+
+-->//Calculate the stiffness of the parts kc
+
+-->kc = 4 * kb
+ kc =
+
+ 4.
+
+-->//Yield tensile strength of chromium-molybdenum steel Syt (N/mm2)
+
+-->Syt = 450
+ Syt =
+
+ 450.
+
+-->//Ultimate tensile strength of chromium-molybdenum steel Sut (N/mm2)
+
+-->Sut = 600
+ Sut =
+
+ 600.
+
+-->//Fatigue stress concentration factor Kf
+
+-->Kf = 3.0
+ Kf =
+
+ 3.
+
+-->//Expected reliability (%)
+
+-->reliability = 90
+ reliability =
+
+ 90.
+
+-->//Factor of safety fs
+
+-->fs = 2
+ fs =
+
+ 2.
+
+-->//Assume diameter of the bolt to be less than 7.5mm for Kb to be 1
+
+-->d = 1
+ d =
+
+ 1.
+
+-->//As Ka is incorporated into Kf, assume the assembly to be ground
+
+-->//This is just to obtain a random value of Ka
+
+-->op = 1
+ op =
+
+ 1.
+
+-->//Inclination of connecting rod to the line of stroke theta (degree)
+
+-->theta = 0
+ theta =
+
+ 0.
+
+
+Core cross-section area of the bolt(A) = 38.128117 mm2
+
\ No newline at end of file diff --git a/764/CH7/EX7.20.b/solution7_20.sce b/764/CH7/EX7.20.b/solution7_20.sce new file mode 100755 index 000000000..68bf7267b --- /dev/null +++ b/764/CH7/EX7.20.b/solution7_20.sce @@ -0,0 +1,72 @@ +
+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)
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