HP 50G, User Manual

Page: 755 / 887

Page 22-40
To find the values of the stresses corresponding to a rotation of 35
o
in the angle
of the stressed particle, we use:
$š
Clear screen, show PICT in graphics screen
@TRACE @
(
x,y
)
@
. To move cursor over the circle showing
φ
and (x,y)
Next, press
™
until you read
φ
= 35. The corresponding coordinates are
(1.63E0, -1.05E1), i.e., at
φ
= 35
o
,
σ
’
xx
= 1.63 kPa, and
σ
’
yy
= -10.5kPa.
An input form for the Mohr’s circle program
For a fancier way to input data, we can replace sub-program INDAT, with the
following program that activates an input form:
«
“MOHR’S CIRCLE” { { “
σ
x:” “Normal stress in x” 0 } {
“
σ
y:” “Normal stress in y” 0 } { “
τ
xy:” “Shear stress” 0}
} { } { 1 1 1 } { 1 1 1 } INFORM DROP
»
With this program substitution, running
@MOHRC
will produce an input form as
shown next:
Press
@@@OK@@@
to continue program execution. The result is the following figure: