From b1f5c3f8d6671b4331cef1dcebdf63b7a43a3a2b Mon Sep 17 00:00:00 2001
From: priyanka
Date: Wed, 24 Jun 2015 15:03:17 +0530
Subject: initial commit / add all books

---
 764/CH7/EX7.20.b/graph7_20.png    | Bin 0 -> 14216 bytes
 764/CH7/EX7.20.b/result7_20.txt   | 119 ++++++++++++++++++++++++++++++++++++++
 764/CH7/EX7.20.b/solution7_20.sce |  72 +++++++++++++++++++++++
 3 files changed, 191 insertions(+)
 create mode 100755 764/CH7/EX7.20.b/graph7_20.png
 create mode 100755 764/CH7/EX7.20.b/result7_20.txt
 create mode 100755 764/CH7/EX7.20.b/solution7_20.sce

(limited to '764/CH7/EX7.20.b')

diff --git a/764/CH7/EX7.20.b/graph7_20.png b/764/CH7/EX7.20.b/graph7_20.png
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diff --git a/764/CH7/EX7.20.b/result7_20.txt b/764/CH7/EX7.20.b/result7_20.txt
new file mode 100755
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+-->//(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)
-- 
cgit