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"cells": [
{
"cell_type": "heading",
"level": 1,
"metadata": {},
"source": [
"Chapter 09: Thin plates"
]
},
{
"cell_type": "heading",
"level": 2,
"metadata": {},
"source": [
"Example 9.1 Pg.No.310"
]
},
{
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"collapsed": false,
"input": [
"from __future__ import division\n",
"import math\n",
"\n",
"h=400 #height of structure (mm)\n",
"l1=300 #length of small section (mm)\n",
"L=1200 #length of whole structure (mm)\n",
"E=70000 #youngs modulus (N/mm^2)\n",
"A_f=350 #area of flange (mm^2)\n",
"A_s=300 # area of stiffeners (mm^2)\n",
"t=2 #thickness (mm)\n",
"I=2000 #second moment of area (mm^4)\n",
"w=5\n",
"#eqn 9.29 tan(a)^4=(1+td/2A_F)/(1+td/2A_S)\n",
"alpha=math.atan(((1+t*h/2/A_f)/(1+t*l1/A_s))**0.25)\n",
"\n",
"#eqn 9.19\n",
"F_T=w*L/h+w/2/math.tan((alpha))\n",
"\n",
"#eqn 9.25 M_max=w*b^2*tan(a)/12/d\n",
"M_max=w*10**3*l1**2*math.tan(alpha)/12/h\n",
"print \"maximum value of bending moment = %1.1e N.mm \\n\"%(M_max)\n",
"\n",
"#eqn 9.23 P=w*b*tan(a)/d\n",
"P=w*l1*math.tan(alpha)/h\n",
"print \"compressive load in stiffener = %1.1f kN \\n\"%(P)\n",
"\n",
"#eqn 9.24 le=d/(4-2b/d)^0.5\n",
"le=h/(4-2*l1/h)**0.5\n",
"print \"equivalent length of stiffener = %3.1f mm\\n\"%(le)\n",
"\n",
"#eqn 8.7 Pcr=pi^2*E*I/le^2\n",
"P_CR=math.pi**2*E*I/le**2\n",
"print \"buckling load of a stiffener = %2.1f kN \\n\"%(P_CR) #approx. value in book"
],
"language": "python",
"metadata": {},
"outputs": [
{
"output_type": "stream",
"stream": "stdout",
"text": [
"maximum value of bending moment = 8.6e+04 N.mm \n",
"\n",
"compressive load in stiffener = 3.4 kN \n",
"\n",
"equivalent length of stiffener = 253.0 mm\n",
"\n",
"buckling load of a stiffener = 21589.8 kN \n",
"\n"
]
}
],
"prompt_number": 13
},
{
"cell_type": "code",
"collapsed": false,
"input": [],
"language": "python",
"metadata": {},
"outputs": []
}
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}
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