HP 48GII, Руководство пользователя, Страница: 755 / 864

Page 22-39
The result is:
Ordering the variables in the sub-directory
Running the program MOHRCIRCL for the first time produced a couple of new
variables, PPAR and EQ. These are the Plot PARameter and EQuation
variables necessary to plot the circle. It is suggest that we re-order the
variables in the sub-directory, so that the programs
@MOHRC
and
@PRNST
are the
two first variables in the soft-menu key labels. This can be accomplished by
creating the list { MOHRCIRCL PRNST } using:
J„ä @MOHRC @PRNST `
And then, ordering the list by using:
„° @)@MEM@@ @)@DIR@@ @ORDER
.
After this call to the function ORDER is performed, press
J
. You will now
see that we have the programs MOHRCIRCL and PRNST being the first two
variables in the menu, as we expected.
A second example of Mohr’s circle calculations
Determine the principal stresses for the stress state defined by
σ
xx
= 12.5 kPa,
σ
yy
= -6.25 kPa, and
τ
xy
= - 5.0 kPa. Draw Mohr’s circle, and determine
from the figure the values of
σ
’
xx
,
σ
’
yy
, and
τ
’
xy
if the angle
φ
= 35
o
.
To determine the principal stresses use the program
@PRNST
, as follows:
J @PRNST
Start program PRNST
12.5˜
Enter
σ
x = 12.5
6.25\˜
Enter
σ
y = -6.25
5
\`
Enter
τ
xy = -5, and finish data entry.
The result is:
To draw Mohr’s circle, use the program
@MOHRC
, as follows: