(HP-65) Vehicle Braking w ⁄ Wheel Hop

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An excerpt from Vehicle Braking w/ Wheel Hop, Master of Science in Mechanical Engineering Thesis, University of Houston, May, 1976, 98 pages

                            ABSTRACT
     It is known [4] that brakes perform better "on the
road" than is anticipated from laboratory tests, even if
the vehicle's wind and rolling resistances are taken into
account. The main reason is "burning rubber" on braking.
The energy partition between tires and brakes can be
readily approximated [3J if the tires run on a perfectly
smooth road. A quasi upper bound case is being considered
here to show what happens if the tire bounces. It will be
shown that a bouncing tire absorbs more energy, but
generally stopping times and distances are longer.

                    TABLE OF CONTENTS
…
APPENDIXES
       D. DESCRIPTION OF 5 CARD PROGRAM FOR HP-65
                   PROGRAMMABLE CALCULATOR................ 75

                           Chapter 1
                        INTRODUCTION
…
     To find the effects of this additional dynamically in-
duced energy loss is the primary objective of this thesis.
More specificially, the investigation is directed towards
finding orders of magnitude on a simplified model that may
be regarded as a quasi upper bound.
…
     A second and separate objective of this thesis is to as-
certain the potential of an HP-65 programmable calculator.
It is found that the entire program for each braking condition
can be put on five memory chips. The calculator proves to be
adequate even with its limited nine register memory and 100
step program capability.
…
     Calculations were performed on an HP-65 programmable
calculator. Data and program steps were entered on magnetic
cards which have a 100 step capacity. Five cards were re-
quired for each braking condition. The actual programs used
are shown on Hewlett Packard forms in Appendix D. Although
the calculator's small memory, nine registers, proved to be
somewhat of a problem, in general, the machine was adequate.
It has the necessary conditionals, and entering data along
with program steps eliminated much key punching. However,
more registers and more program steps would have been helpful.
     The programed calculator was used to determine values
for velocity, distance travelled, tire angular velocity, and
energy dissipated in the brake and at the tire contact patch
at the end of each braking cycle. These points were plotted
and joined by smooth curves. The curves do not show in detail
how distance, energy, or velocity vary with time within the
cycle but give an overall picture through the whole stopping
time. Figures 10.2 to 10.5 show in detail how velocity,
distance, and energy dissipated in brake and tire vary over
a typical braking cycle.
…
                                    Appendix D
        DESCRIPTION OF 5 CARD PROGRAM FOR HP-65
                     PROGRAMMABLE CALCULATOR
…
    HP-65 Program Form
Braking Analysis - CARD 1
…
    HP-65 Program Form
Braking Analysis - CARD 3
…
    HP-65 Program Form
Braking Analysis - CARD 3
…
    HP-65 Program Form
Braking Analysis - CARD 4
…
    HP-65 Program Form
Braking Analysis - CARD 5
…

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