This program computes the mechanical characteristics
of a leaf-spring suspension and searches for a spring
geometry with a long and constant free period.
Files: leaf.in ==> leafspring ==> leaf.out and spring.out
Program option controlled by the first input parameter:
iopt = 0, all done
= 1, compute properties of given spring geometry
= 2, find astatic geometry with constant frequency
= 3, find same with nonsymmetric circular spring
= 4, find same with symmetric noncircular spring
iopt = 3 and 4: xo,yo,wo are determined from the desired
spring geometry, not taken from the input file
iopt = 9, ignore this input line
Option in effect: iopt=1
Parameters read from file leaf.in:
xu yu wu xo yo wo fl ax
1.958 -5.803 180.000 1.960 5.780 0.000 16.300 0.000
fk wi th em xki yki di
0.000 5.000 0.021 1900000.000 0.000 -0.300 2.400
unf unl
0.000 0.000
iopt: program option, see above
xu, yu, wu: coordinates and angle of one end of the spring
xo, yo, wo: same for the other end of the spring. coordinates in
cm from the hinge. angles in degrees ccw from the
x axis. spring may be rotated around the hinge.
fl, ax, fk: length of the spring, angle of the axis of sensitivity
against the vertical, initial curvature of the spring
(end-to-end, without load) in degrees.
wi, th, em: width, thickness, elast. modulus of the spring
xki,yki,di: estimated spring force and moment
unf,unl: eigenfrequency-squared and its derivative w.r.t.
position due to causes unaccounted for in this program
spring: width 5.0 cm, thickness 0.21 mm, emodul 20267. kp/mm**2
Final spring geometry. Units are cm, kp, kg. Mass is 5 cm from hinge.
xu= 1.958 yu= -5.803 wu=180.000
xo= 1.960 yo= 5.780 wo= 0.000
fr^2= 0.001 nlin1= 0.000 nlin2= 0.836
rmax= 7.294 rmin= 3.344 rlim= 2.940
mass= 0.361 =?= mass= 0.361 masslim= 0.531
xfrc= -0.000 yfrc= -0.281 torq= 2.356
Explanation of symbols: xu, yu, wu, xo, yo, wo as above.
fr^2, nlin1, nlin2: squared frequency and its first two
derivatives with respect to the mass position (length unit = cm)
rmax, rmin: max. and min. radius of curvature of the spring
rlim: min. radius of curv. permitted by max. strain 1/280.
mass: weight of the mass in kp, calculated in two different ways
masslim: weight with a spring of same width but maximum thickness
xfrc, yfrc, torq: force and torque in both clamps (kp and kp*cm)
Extremal coordinates of the spring
xmin=-2.603 xmax= 1.960 ymin=-5.803 ymax= 5.780
Shape of spring is stored in file spring.out
Routine BLF was called 110 times.
Use xfrc, yfrc, torq as initial values xki, yki, di.
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