{
"cells": [
{
"cell_type": "markdown",
"metadata": {},
"source": [
"# Ch:19 Flywheel"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## exa 19-1 - Page 530"
]
},
{
"cell_type": "code",
"execution_count": 1,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"axial stress is 12.76 MPa \n",
"\n",
"tensile stress for theta=30deg is 38.9 MPa \n",
"\n",
"tensile stress for theta=0deg is 31.74 MPa \n"
]
}
],
"source": [
"from __future__ import division\n",
"from math import sqrt, pi, cos, sin\n",
"R=1200#\n",
"b=300#\n",
"t=150#\n",
"N=500#\n",
"m=7100*10**-9*b*t#\n",
"Ar=b*t#\n",
"Aa=Ar/4#\n",
"C=(20280/t**2)+0.957+(Ar/Aa)#\n",
"w=2*pi*N/60#\n",
"V=w*R*10**-3#\n",
"siga=2*10**3*m*V**2/(C*Aa*3)#\n",
"theta=30*pi/180#\n",
"alpha=30*pi/180#\n",
"x1=10**3*m*(V**2)/(b*t)#\n",
"y1=cos(theta)/(3*C*sin(alpha))#\n",
"z1=2000*R*10**-3/(C*t)*((1/alpha)-(cos(theta)/sin(alpha)))#\n",
"sigrr1=x1*(1-y1+z1)#\n",
"theta=0*pi/180#\n",
"x2=10**3*m*(V**2)/(b*t)#\n",
"y2=cos(theta)/(3*C*sin(alpha))#\n",
"z2=2000*R*10**-3/(C*t)*((1/alpha)-(cos(theta)/sin(alpha)))#\n",
"sigrr2=x2*(1-y2-z2)#\n",
"print \"axial stress is %0.2f MPa \"%(siga)#\n",
"print \"\\ntensile stress for theta=30deg is %0.1f MPa \"%(sigrr1)#\n",
"print \"\\ntensile stress for theta=0deg is %0.2f MPa \"%(sigrr2)#\n",
"#The difference in the value of sigrr1 and sigrr2 is due to rounding-off of values."
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## exa 19-2 - Page 530"
]
},
{
"cell_type": "code",
"execution_count": 2,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"t is 63.37 mm \n",
"\n",
"b is 126.74 mm \n",
"\n",
"R is 0.682 m \n"
]
}
],
"source": [
"from math import asin, cos, sqrt,pi\n",
"N=350#\n",
"theta1=asin(sqrt((3-0.6)/4))#\n",
"theta1=theta1*180/pi#\n",
"theta2=(180)-theta1#\n",
"#Ti=16000+6000*sind(3*theta)#\n",
"#To=16000+3600*sind(theta)#\n",
"a=-3600*(cos(pi/180*theta2)-cos(pi/180*theta1))#\n",
"b=2000*(cos(pi/180*3*theta2)-cos(pi/180*3*theta1))#\n",
"c=a+b#\n",
"delU=c#\n",
"Ks=0.05#\n",
"w=2*pi*N/60#\n",
"I=delU/(Ks*w**2)#\n",
"V=25#\n",
"Ir=I*0.95#\n",
"R=V/w#\n",
"Mr=Ir/R**2#\n",
"rho=7150#\n",
"t=sqrt(Mr*(10**6)/(2*pi*R*2*rho))#\n",
"b=2*t#\n",
"print \"t is %0.2f mm \"%(t)#\n",
"print \"\\nb is %0.2f mm \"%(b)#\n",
"print \"\\nR is %0.3f m \"%(R)#"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## exa 19-3 - Page 531"
]
},
{
"cell_type": "code",
"execution_count": 3,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"t is 28.16 mm \n",
"\n",
"b is 42.24 mm \n",
"\n",
"R is 0.2816 m \n"
]
}
],
"source": [
"from math import sqrt,pi\n",
"N=300#\n",
"Ks=0.03#\n",
"rho=7150#\n",
"Kr=0.9#\n",
"w=2*pi*N/60#\n",
"WD=(300*2*pi)+(4*pi*200/4)#\n",
"Tm=400#\n",
"delU=pi*200/16#\n",
"Ir=Kr*delU/(w**2*Ks)#\n",
"R=Ir/(rho*1.5*0.1*0.1*2*pi)#\n",
"R=R**(1/5)#\n",
"t=0.1*R*1000#\n",
"b=1.5*t#\n",
"print \"t is %0.2f mm \"%(t)#\n",
"print \"\\nb is %0.2f mm \"%(b)#\n",
"print \"\\nR is %0.4f m \"%(R)#"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## exa 19-4 - Page 532"
]
},
{
"cell_type": "code",
"execution_count": 4,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"t is 26.9 mm \n",
"\n",
"b is 53.8 mm \n",
"\n",
"R is 0.5 m \n"
]
}
],
"source": [
"from math import sqrt,pi\n",
"d=20#\n",
"t=12#\n",
"Tus=450#\n",
"Pmax=pi*d*t*Tus#\n",
"WD=Pmax*t/2*10**-3#\n",
"n=0.95#\n",
"Wi=WD/n#\n",
"delU=5*Wi/6#\n",
"N=300#\n",
"w=2*pi*N/60#\n",
"Ks=0.2#\n",
"I=delU/(Ks*w**2)#\n",
"Ir=I*0.9#\n",
"R=0.5#\n",
"m=Ir/R**2#\n",
"rho=7150#\n",
"t=sqrt(m*10**6/(rho*2*pi*R*2))#\n",
"b=2*t#\n",
"print \"t is %0.1f mm \"%(t)#\n",
"print \"\\nb is %0.1f mm \"%(b)#\n",
"print \"\\nR is %0.1f m \"%(R)#"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## exa 19-5 - Page 533"
]
},
{
"cell_type": "code",
"execution_count": 5,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"R is 0.364 m \n",
"\n",
"sigmax is 0.29 MPa \n"
]
}
],
"source": [
"from math import sqrt,pi\n",
"U=(500*2*pi)+(3*pi*500/2)#\n",
"Tm=U/(2*pi)#\n",
"delU=2.25*pi*125/2#\n",
"Ks=0.1#\n",
"N=250#\n",
"w=2*pi*N/60#\n",
"I=delU/(Ks*w**2)#\n",
"t=0.03#\n",
"rho=7800#\n",
"R=(I*2/(pi*rho*t))**(1/4)#\n",
"V=R*w#\n",
"v=0.3#\n",
"sigmax=rho*V**2*(3+v)/8*10**-6#\n",
"print \"R is %0.3f m \"%(R)#\n",
"print \"\\nsigmax is %0.2f MPa \"%(sigmax)#\n",
" "
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## exa 19-6 - Page 534"
]
},
{
"cell_type": "code",
"execution_count": 6,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"t is 24.8 mm \n",
"\n",
"b is 37.2 mm \n"
]
}
],
"source": [
"from math import sqrt,pi\n",
"N=1.5*8*60#\n",
"l=200#\n",
"t=1.5/2#\n",
"W=350*10**3#\n",
"WD=0.15*l*W*10**-6#\n",
"n=0.9# #since frictional effect is 10%, effciency of system is 90%\n",
"Wi=WD/n#\n",
"L=400#\n",
"delU=(L-(0.15*l))/(L)*10**3*Wi#\n",
"Ks=0.12#\n",
"w=2*pi*N/60#\n",
"I=delU/(Ks*w**2)#\n",
"Ir=I*0.9#\n",
"R=0.7#\n",
"m=Ir/R**2#\n",
"rho=7150#\n",
"t=sqrt(m*10**6/(rho*2*pi*R*1.5))#\n",
"b=1.5*t#\n",
"print \"t is %0.1f mm \"%(t)#\n",
"print \"\\nb is %0.1f mm \"%(b)#"
]
},
{
"cell_type": "markdown",
"metadata": {},
"source": [
"## exa 19-7 - Page 535"
]
},
{
"cell_type": "code",
"execution_count": 7,
"metadata": {
"collapsed": false
},
"outputs": [
{
"name": "stdout",
"output_type": "stream",
"text": [
"t is 40 mm \n",
"\n",
"b is 80 mm \n",
"\n",
"R is 400 mm \n"
]
}
],
"source": [
"from math import sqrt,pi\n",
"N=144#\n",
"#Let n be no. of punches/ min\n",
"n=8#\n",
"#Let t be timr for 1 punch\n",
"t=60/n#\n",
"theta=N/60*2*pi*0.6#\n",
"T=2.1#\n",
"U=T*theta#\n",
"#Let U1 be revolution of crankshaft in t sec\n",
"U1=t*N/60*2*pi#\n",
"delU=(U1-theta)/U1*U*10**3#\n",
"w=2*pi*1440/60#\n",
"Ks=0.1#\n",
"I=delU/(Ks*w**2)#\n",
"Ir=I*0.9#\n",
"rho=7100#\n",
"\n",
"R=Ir/(rho*0.2*0.1*2*pi)#\n",
"R=R**(1/5)#\n",
"t=0.1*R*1000#\n",
"b=0.2*R*10**3#\n",
"t=40#\n",
"b=80#\n",
"R=400#\n",
"# printing data in scilab o/p window\n",
"print \"t is %0.0f mm \"%(t)#\n",
"print \"\\nb is %0.0f mm \"%(b)#\n",
"print \"\\nR is %0.0f mm \"%(R)#"
]
}
],
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"kernelspec": {
"display_name": "Python 2",
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"name": "python2"
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"file_extension": ".py",
"mimetype": "text/x-python",
"name": "python",
"nbconvert_exporter": "python",
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