# Variables
b = 225.; #in mm
h = 10. #in mm
l = 1100.; #in mm
f1 = 250.; #in N
f2 = 350; #in N at which glass breaks
# Calculations
m = f1*l/4.; #in N-mm
f = f1/2.; #in N
a = (6*m)/(b*h**2); #in N/mm**2
t = (3*f)/(2*b*h); #in N/sqmm
r = f2*l/4; #in N-mm
i = (b*h**3)/12; #in mm**4
y = h/2; #in mm
mr = r*y/i; #in n/sqmm
# Results
print "Flexural Strength (in N/sqmm) = %.2f N/mm**2"%a
print "Shear Strength (in N/sqmm) = %3f N/mm**2"%t
print "Modulous of Rupture (in N/sqmm) = %.2f N/mm**2"%mr
import math
# Variables
d = 5.; #in mm
# Calculations
id = 32.5/10; #indentation diameter in mm
p = 30*d**2; #load for steel specimen in kgf
bhn = p/((3.14*d/2)*(d-math.sqrt(d**2-id**2))); #in kgf/sqmm
# Results
print "Load P for steel specimen (in kgf) = %.f kgf"%p
print "BRINELL HARDNESS NUMBER of the steel specimen = %.1f"%bhn
import math
# Variables
l = 0.1; #frictinal and windage losses in kgf-m
dr = 5.9; #dial reading in kgf-m
w = 19.33; #weight of hammer in kgf-m
t = 10.; #in mm
ui = 30.; #in kgf-m
a = 160.; #angle in degrees
r = 0.8; #swing radius in m
# Calculations
u = dr-l; #in kgf-m
d = t/5; #depth of V-notch in mm
te = t-d; #effective thickness in mm
ve = 75.*10*te; #effective volume in cu. mm
vem = ve*10.**-9; #in cu. m
mr = u/vem; #in kgf/sqm
ae = t*te; #effective area of cross section in sqmm
aem = ae*10**-6; #in sqm
is_ = u/aem; #in kg/m
uf = ui-u; #in kgf-m
hf = uf/w; #in m
B = math.degrees(math.acos(1-(uf/(w*r))))
# Results
print "Rupture Energy (in kgf-m) = %.1f kgf-m"%u
print "Modulous Of Rupture (in kgf/sqm) = %.1e kgf/m**2"%mr
print "Notch Imapct Strength (in kg/m) = %.2e kgm"%is_
print "Height risen by Hammer (in m) = %.2f m"%hf
print "Angle after Breaking the specimen (in degress) = %.1f degrees"%(B)
# Variables
a_m = 70.; #mean stress in Mpa
a_r = 210.; #stress amplitude in Mpa
# Calculations
a_max = ((2*a_m)+a_r)/2; #maximum stress in MPa
a_min = 2*a_m-a_max; #Minimum stress in MPa
s = a_min/a_max; #stress ratio
sr = a_max-a_min; #stress range in MPa
# Results
print "Maximum Stress Level (in MPa) = ",a_max
print "Minimum Stress Level (in MPa) = ",a_min
print "Stress Ratio = ",s
print "Stress Range (in MPa) = ",sr
# Variables
p_min = 20.; #in kN
p_max = 50.; #in kN
l = 500.; #in mm
d = 60.; #in mm
a_u = 650.; #in MPa
a_y = 520.; #in MPa
fos = 1.8; #factor of safety
# Calculations
m_max = p_max*l/4; #maximum bending moment in kN mm
m_min = p_min*l/4; #minimum bending moment in kN mm
m_m = (m_max+m_min)/2; #mean bending moment in kN mm
m_a = (m_max-m_min)/2; #alternating bending moment in kN mm
z = 3.14*d**3/32;
a_m = (m_m/z)*1000; #mean bending stress in MPa
a_a = (m_a/z)*1000; #alternating bending stress in MPa
a_e1 = a_a/((1/fos)-(a_m/a_u)**2*fos); #in MPa
a_e2 = a_a/((1/fos)-(a_m/a_u)); #in MPa
a_e3 = a_a/((1/fos)-(a_m/a_y)); #in MPa
# Results
print "ENDURANCE STRESS FROM Gerbers Parabolic Function (in MPa) = %.2f MPa"%a_e1
print "ENDURANCE STRESS FROM Goodman Straight Line Relation (in MPa) = %.2f MPa"%a_e2
print "ENDURANCE STRESS FROM Soderberg Straight Line Relation (in MPa) = %.2f MPa"%a_e3