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{
"metadata": {
"name": ""
},
"nbformat": 3,
"nbformat_minor": 0,
"worksheets": [
{
"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chatper 19 : Composite Materials"
]
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 19.1 pageno : 507"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"# Variables\n",
"t_s = 3.;\t\t\t#in mm\n",
"t_c = 24.;\t\t\t#in mm\n",
"b = 100.;\t\t\t#in mm\n",
"\n",
"# Calculations\n",
"d = (t_s+t_c)/2;\t\t\t#in mm\n",
"is_ = ((b*t_s**3)/12)+(b*t_s*d**2);\t\t\t#in mm**4\n",
"ic = b*t_c**3/12 \t\t\t#in mm**4\n",
"Es = 7000.; \t\t\t #moduli of polyester skin in N/mm**2\n",
"m_f = 20.; \t\t\t #moduli of foam core in N/mm**2\n",
"d_fr = (2*Es*is_)+(m_f*ic);\t\t\t #in N/mm**2\n",
"\n",
"Ts = 6\n",
"D_s = (Es*b*Ts**2)/12\n",
"c = d_fr/D_s\n",
"\n",
"# Results\n",
"print \"Flexural rigidity (in N/sqm) = %.2e\"%d_fr\n",
"print \"Ds = %.1e N mm**2\"%D_s\n",
"print \"Flexural rigidity of sandwich beam is %d times more\"%c\n",
"\n",
"\n",
"# Note : answer in book is wrong for D_s please check manually."
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Flexural rigidity (in N/sqm) = 7.71e+08\n",
"Ds = 2.1e+06 N mm**2\n",
"Flexural rigidity of sandwich beam is 367 times more\n"
]
}
],
"prompt_number": 3
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 19.2 page no : 520"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"# Variables\n",
"ec = 210.;\t\t\t#in GPa\n",
"ea = 71.;\t\t\t#in GPa\n",
"eb = 440.;\t\t\t#in GPa\n",
"\n",
"# Calculations\n",
"va = (ec-eb)/(ea-eb);\n",
"vb = 1-va;\n",
"c = vb/va;\n",
"\n",
"# Results\n",
"print \"Volume ratio = %.2f\"%c\n",
"\n",
"# note : answer in book is wrong . please calculate manually.\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Volume ratio = 0.60\n"
]
}
],
"prompt_number": 2
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 19.3 pageno : 521"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"# Variables\n",
"ef = 430.;\t\t\t#in GPa\n",
"e = 3.6;\t\t\t#in GPa\n",
"m = ef/e;\n",
"vf = 0.15;\t\t\t#by volume\n",
"\n",
"# Calculations\n",
"vm = 1-vf;\n",
"x = vm/vf;\n",
"pf = m;\n",
"pc = m+x;\n",
"y = pf/pc;\n",
"vf1 = 0.65\n",
"vm1 = 1-vf1;\n",
"z = vm1/vf1;\n",
"pc1 = m+z;\n",
"zz = pf/pc1;\n",
"\n",
"# Results\n",
"print \"fraction of load carried by fibres (15 %% by volume) = %.2f\"%y\n",
"print \"fraction of load carried by fibres (65 %% by volume) = %.4f\"%zz\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"fraction of load carried by fibres (15 % by volume) = 0.95\n",
"fraction of load carried by fibres (65 % by volume) = 0.9955\n"
]
}
],
"prompt_number": 14
},
{
"cell_type": "heading",
"level": 3,
"metadata": {},
"source": [
"Example 19.4 page no : 522"
]
},
{
"cell_type": "code",
"collapsed": false,
"input": [
"\n",
"# Variables\n",
"vf = 0.65;\n",
"vm = 1-vf;\n",
"kts = 2.8; \t\t\t#in Gpa\n",
"ets = 0.0025;\t\t\t#in GPa\n",
"\n",
"# Calculations and Results\n",
"ac = (kts*vf)+(ets*vm);\t\t\t#in GPa\n",
"print \"Longitudinal Strength (in GPa) = %.2f\"%ac\n",
"\n",
"ktm = 130.;\t\t\t#in GPa\n",
"etm = 3.5;\t\t\t#in GPa\n",
"ec = (ktm*vf)+(etm*vm);\n",
"print \"Longitudianl Modulous (in GPa) = %.2f\"%ec\n",
"\n",
"e_c = 1/((vf/ktm)+(vm/etm));\n",
"print \"Transverse Modulous (in GPa) = %.2f\"%e_c\n",
"\n",
"kp = 0.34;\t\t\t#in GPa\n",
"ep = 0.36;\t\t\t#in GPa\n",
"vlt = (vf*kp)+(vm*vm);\n",
"print \"Poissons Ratio = \",vlt\n",
"\n",
"glt = 1./((vf/2.2)+(vm/1.2));\t\t\t#in GPa\n",
"print \"Shear Modulous (in GPa) = %.2f\"%glt\n",
"\n",
"# note: answer in book is wrong for part a. please calculate manually.\n"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"Longitudinal Strength (in GPa) = 1.82\n",
"Longitudianl Modulous (in GPa) = 85.72\n",
"Transverse Modulous (in GPa) = 9.52\n",
"Poissons Ratio = 0.3435\n",
"Shear Modulous (in GPa) = 1.70\n"
]
}
],
"prompt_number": 17
}
],
"metadata": {}
}
]
}
|