Files
engineering/plate.py
2019-02-08 10:22:48 +01:00

125 lines
3.8 KiB
Python
Executable File

#!/usr/bin/env python
# -*- coding: utf-8 -*-
"""\
Circular plate
"""
from __future__ import absolute_import, division, print_function, unicode_literals
from math import sqrt
__author__ = "Daniel Weschke"
__copyright__ = "Copyright 2019 Daniel Weschke"
__credits__ = ["Daniel Weschke"]
__license__ = "MIT"
__version__ = "2019.01.17"
__maintainer__ = "Daniel Weschke"
__email__ = "daniel.weschke@directbox.de"
__status__ = "Production" # "Prototype", "Development", "Production"
VERSION = """\
%(prog)s version {version} {copyright}
For Unicode characters check the file encoding that the console is using.
Windows user may execute the command "chcp 65001".""".format(
version=__version__, copyright=__copyright__)
EPILOG = """\
"""
def deflection_pinned(p, r, nu, E, t):
"""\
Central deflection of a pinned supported circular plate.
p pressure
r radius
nu Poisson's ratio
E Young's modulus
t thickness
"""
return p*r**4*(5+nu)/(64*(1+nu))*(12*(1-nu**2))/(E*t**3)
def deflection_clamped(p, r, nu, E, t):
"""\
Central deflection of a clamped supported circular plate.
p pressure
r radius
nu Poisson's ratio
E Young's modulus
t thickness
"""
return p*r**4*(1)/(64)*(12*(1-nu**2))/(E*t**3)
def thickness_min(p, d, Rp02, S):
"""\
Minimum thickness of a circular plate.
p pressure
d diameter
Rp02 mechanical strength
S safety factor
"""
return 0.554*d*sqrt(p*S/Rp02)
def allowable_stress(sigma, S):
"""\
Allowable stress.
sigma stress
S safety factor
"""
return sigma/S
def main():
"""\
Main function
"""
import argparse
parser = argparse.ArgumentParser(
description=__doc__, prefix_chars='-', epilog=EPILOG,
#usage="%(prog)s [OPTION]... NAME",
formatter_class=argparse.RawTextHelpFormatter,
)
parser.add_argument('-v', '--verbose', action="store_true", help="Verbose output")
parser.add_argument('-V', '--version', action='version', version=VERSION)
parser.add_argument('-D', '--debug', dest='debug', action='store_true', help=argparse.SUPPRESS)
subparsers = parser.add_subparsers(help='', dest='case')
parser_a = subparsers.add_parser(
'deflection', help="central deflection", prefix_chars='-',
description="Central deflection of a circular plate.")
parser_a.add_argument('P', nargs='?', type=float, default=0.1, help='pressure [default: 0.1 (MPa = 1 bar)]')
parser_a.add_argument('NU', type=float, help='Poisson\'s ratio (CVD diamond 0.1)')
parser_a.add_argument('R', type=float, help='radius')
parser_a.add_argument('E', type=float, help='Young\'s modulus (CVD diamond 1.05e6)')
parser_a.add_argument('T', type=float, help='thickness')
parser_a.add_argument('-p', '--pinned', action="store_true", help='pinned support')
parser_a.add_argument('-c', '--clamped', action="store_true", help='clamped support')
parser_b = subparsers.add_parser(
'thickness', help="minimum thickness", prefix_chars='-',
description="Minimum thickness of a circular plate.")
parser_b.add_argument('P', nargs='?', type=float, default=0.1, help='pressure [default: 0.1 (MPa = 1 bar)]')
parser_b.add_argument('D', type=float, help='diameter')
parser_b.add_argument('SIG', type=float, help='mechanical strength (CVD diamond 2000..400)')
parser_b.add_argument('S', nargs='?', type=float, default=4., help='safety factor [default: 4]')
args = parser.parse_args()
if args.debug:
print(args)
if args.case == 'deflection':
if args.pinned:
print(deflection_pinned(args.P, args.R, args.NU, args.E, args.T))
elif args.clamped:
print(deflection_clamped(args.P, args.R, args.NU, args.E, args.T))
else:
print('error: define a support type.')
return 2
elif args.case == 'thickness':
print(thickness_min(args.P, args.D, args.SIG, args.S))
return 0
if __name__ == "__main__":
import sys
sys.exit(main())