HP 15C:
Soderberg’s Equation for Fatigue
Source: Step by Step Solutions for your HP
Calculator: Engineering Applications.
HP-32S. Hewlett Packard. Corvallis, OR. 1988
pg. 52-54
Equation:
Syp/FS =
(Smax + Smin)/2 + K * (Syp/Se) * ((Smax – Smin)/2)
Variables:
R0 = Syp =
yield point stress
R1 = Se =
endurance stress reversed bending tests
R2 = Smax =
maximum applied stress
R3 = Smin =
minimum applied stress
R4 = K =
stress concentration factor
R5 = FS =
factor of safety
Instructions:
Enter the
known values in each of the variables.
Enter the number of the variable to be solved in register I ( [ STO ] [
TAN ] (I) ). To solve, enter a range,
and press [ f ] [ ÷ ] (SOLVE), [ e^x ] (B). (*or whatever label you assigned
this program to)
Program:
|
Step
|
Key
|
Key Code
|
|
001
|
LBL B
|
42, 21, 12
|
|
002
|
STO (i)
|
44, 24
|
|
003
|
RCL 0
|
45, 0
|
|
004
|
RCL÷ 5
|
45, 10, 5
|
|
005
|
RCL 2
|
45, 2
|
|
006
|
RCL+ 3
|
45, 40, 3
|
|
007
|
2
|
2
|
|
008
|
÷
|
10
|
|
009
|
-
|
30
|
|
010
|
RCL 2
|
45, 2
|
|
011
|
RCL- 3
|
45, 30, 3
|
|
012
|
2
|
2
|
|
013
|
÷
|
10
|
|
014
|
RCL* 0
|
45, 20, 0
|
|
015
|
RCL÷ 1
|
45, 10, 1
|
|
016
|
RCL* 4
|
45, 20, 4
|
|
017
|
-
|
30
|
|
018
|
RTN
|
43, 32
|
Example:
Find the
yield point (R0) given the following:
R1 = Se =
33,000 psi
R2 = Smax =
20,000 psi
R3 = Smin =
10,000 psi
R4 = K = 1.5
R5 = FS = 2
Store 0 in
RI.
Solution: 55,000 psi
This blog is property of Edward Shore. 2016