blob: ca43440b78d6bc1dafde7e2a10876e969390282e (
plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
|
clc;
clear;
mprintf('MACHINE DESIGN \n Timothy H. Wentzell, P.E. \n EXAMPLE-3.2 Page No.43\n');
b=2; //[in] Width of beam
h=2; //[in] Height of beam
I=(b*h^3)/12; //[in^4] Moment of inertia
F=3000; //[lb] Load applied to beam
L=36; //[in] Length of beam
c=1; //[in] Distance of outer most fiber from neutral axis
E=30*10^6; //[lb/in^2] Modulus of elasticity
Sy=30000; //[lb/in^2] Yield strength
Su=55000; //[lb/in^2] Ultimate strength
SF=2; //[] Safety factor based on ultimate stress
M=F*L/4; //[lb*in] Bending moment
S=(M/I)*c; //[lb/in^2] Bending stress
//Note-In the book I=1.33 in^4 is used instead of I=1.3333333 in^2
mprintf('\na. The maximum stress in beam is %f lb/in^2',S);
delta=-F*L^3/(48*E*I); //[in] Maximum deflection in this beam
mprintf('\nb. The maximum deflection in this beam is %f in.',delta);
if Sy>S then
mprintf('\nc. Yes, the stress of %f lb/in^2 is less than the yield of Sy=%f lb/in^2.',S,Sy);
else
mprintf('\nc. No, the stress of %f lb/in^2 is greater than the yield of Sy=%f lb/in^2',S,Sy);
end
Sall=Su/SF; //[lb/in^2] Allowable stress
if Sall>S then
mprintf('\nd. It is acceptable because allowable stress is greater than the acttual stress of %f lb/in^2.',S);
else
mprintf('\nd. Design is not acceptable because allowable stress is less than the actual stress of %f lb/in^2.',S)
end
//Note: The deviation of answer from the answer given in the book is due to round off error.(In the book values are rounded while in scilab actual values are taken)
|
