{
"metadata": {
"name": "",
"signature": "sha256:4885451d1eb84f1c7ede3570bb9a4c180b0235da374d3be406dcc799b426e236"
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"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Ch:9 Threaded Fasteners"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"exa 9-1 - Page 266"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import pi\n",
"p1=2#\n",
"d=16#\n",
"dt1=d-(0.93825*p1)#\n",
"At1=pi*dt1**2/4#\n",
"p2=1.5#\n",
"d=16#\n",
"dt2=d-(0.93825*p2)#\n",
"At2=pi*dt2**2/4#\n",
"\n",
"print \" At1 is %0.1f mm**2 \"%(At1)#\n",
"print \"\\n At2 is %0.1f mm**2 \"%(At2)#"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" At1 is 156.7 mm**2 \n",
"\n",
" At2 is 167.2 mm**2 \n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"exa 9-2 - Page 266"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"W=20*10**3#\n",
"n=4#\n",
"#Let the load on each bolt be W1\n",
"W1=W/n#\n",
"At=W1/80#\n",
"\n",
"print \"At is %0.1f mm**2 \"%(At)#"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"At is 62.0 mm**2 \n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"exa 9-3 - Page 267"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import atan, tan, cos\n",
"d=18#\n",
"p=2.5#\n",
"dr=d-(1.2268*p)#\n",
"dm=(d+dr)/2#\n",
"alpha=atan(p/(pi*dm))#\n",
"theta=pi*30/180#\n",
"u1=0.15#\n",
"u2=0.13#\n",
"x=(tan(alpha)+(u1/cos(theta)))/(1-(tan(alpha)*u1/cos(theta)))#\n",
"K=dm*x/(2*d)+(0.625*u2)#\n",
"print \"K is %0.5f \"%(K)#"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"K is 0.18343 \n"
]
}
],
"prompt_number": 4
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"exa 9-4 - Page 267"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import log\n",
"d=20#\n",
"t=4#\n",
"Lg=84#\n",
"Ad=pi*d**2/4#\n",
"Eb=205*10**3#\n",
"Ed=105*10**3#\n",
"kb=Ad*Eb/Lg#\n",
"lg=80#\n",
"x=5*(lg+(0.5*d))/(lg+(2.5*d))#\n",
"kp=pi*Ed*d/(2*log(x))#\n",
"At=245#\n",
"sigb=105#\n",
"Pe=20*10**3#\n",
"Pb=Pe*kb/(kb+kp)#\n",
"sigad=Pb/At#\n",
"finalst=sigb+sigad#\n",
"\n",
"print \"final stress is %0.2f N/mm**2 \"%(finalst)#"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"final stress is 123.28 N/mm**2 \n"
]
}
],
"prompt_number": 5
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"exa 9-5 - Page 268"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"Eb=207*10**3#\n",
"Ec=105*10**3#\n",
"sigp=650#\n",
"At=115#\n",
"Pi=0.75*sigp*At#\n",
"F=sigp*At#\n",
"#Let the additional load Fadd\n",
"Padd=F-Pi#\n",
"d=14#\n",
"Ad=pi*d**2/4#\n",
"Lg=63#\n",
"kb=Ad*Eb/Lg#\n",
"lg=60#\n",
"x=5*(lg+(0.5*d))/(lg+(2.5*d))#\n",
"km=pi*Ec*d/(2*log(x))#\n",
"C=kb/(kb+km)#\n",
"Pe=Padd/C#\n",
"K=0.2#\n",
"Ti=Pi*K*d*10**-3#\n",
"\n",
"print \"Ti is %0.2f Nm \"%(Ti)#"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Ti is 156.97 Nm \n"
]
}
],
"prompt_number": 6
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"exa 9-6 - Page 269"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"d=20#\n",
"sigp=600#\n",
"At=245#\n",
"Pi=120*10**3#\n",
"Pe=30*10**3#\n",
"C=0.35#\n",
"Pb=C*Pe#\n",
"P=Pi+Pb#\n",
"sigi=Pi/At#\n",
"sigf=P/At#\n",
"K=0.18#\n",
"T=K*d*Pi*10**-3#\n",
"E1=sigi/sigp#\n",
"E2=sigf/sigp#\n",
"\n",
"print \" sigi is %0.1f MPa \"%(sigi)#\n",
"print \"\\n sigi is %0.2f MPa \"%(sigf)#\n",
"print \"\\n T is %0.0f Nm \"%(T)#\n",
"print \"\\n E1 is %0.3f \"%(E1)#\n",
"print \"\\n E2 is %0.3f \"%(E2)#\n",
" \n",
" #Value upto tenthth place is considered in the book for value of final stress in bolt, 'sigf'"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
" sigi is 489.0 MPa \n",
"\n",
" sigi is 532.65 MPa \n",
"\n",
" T is 432 Nm \n",
"\n",
" E1 is 0.000 \n",
"\n",
" E2 is 0.888 \n"
]
}
],
"prompt_number": 7
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"exa 9-7 - Page 269"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"from math import sqrt\n",
"p=2#\n",
"d=16#\n",
"dt=d-(0.938*p)#\n",
"At=pi*dt**2/4#\n",
"r=60*sqrt(2)#\n",
"Td=1/(4*At)#\n",
"Ta=120#\n",
"T=8.722*10**-3#\n",
"P=Ta/T*10**-3#\n",
"\n",
"print \"P is %0.3f kN \"%(P)#\n",
" \n",
" #Value upto hundredth place is considered in the book for value of permissible load, 'P'"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"P is 13.758 kN \n"
]
}
],
"prompt_number": 8
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"exa 9-8 - Page 270"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"sigyp=460#\n",
"FOS=2#\n",
"Ts=0.577*sigyp/FOS#\n",
"At=245#\n",
"r=100#\n",
"P=Ts*At/1.453*10**-3#\n",
"print \"The eccentric load is %f N \"%(P)\n",
"print \"P is %0.3f kN \"%(P)#\n",
"#Value of thousandth place of eccentric load, 'P' is misprinted in the book. "
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"The eccentric load is 22.377116 N \n",
"P is 22.377 kN \n"
]
}
],
"prompt_number": 9
}
],
"metadata": {}
}
]
}