🚀 go-pugleaf

Adam,

        Sorry,  I don't know about one that high school students could use
to analyse a bridge.

        This past year, my students were involved in the Pittsbvurgh
Supercomputing Center High School Outreach Program.  They did many things
as part of the project.  The main goal of the project was to analyse the
vibration in the bridge deck. and write a program in FORTRAN that would
simulate the bounce of the bridge deck and then enter the resulting data
into a grphics package that would permit the CRAY C90 in Pittsburgh to
produce a "filmloop" of the vibrating bridge deck.

        Bridges are not the simple structure that most people believe them
to be.

  The program required knowledge of the amount of vertical
deflection for the mid point of the span, the speed of deflection,
the acceleration of the deflection, the stiffness of the bridge, the
stiffness of the springs of the vehicle causing the bridge to vibrate, the
distance the vehicles springs deflected, the speed of deflection of the
springs, and the acceleration of the spring deflection.
All of this information had to be manipulated by the program for every
position of the vehicle on the bridge deck.  This turned out to be the
equivalent of a graduate numerical analysis project for Civil Engineers or
Computer Science  Masters Degree candidates.  Luckily, one of my
programming advisors realised the difficulty of what my students were
trying to do and gave us access to a subroutine that did everything that
we needed.  This involved HEAVY first and second order differential equations.

        The students wrote the remainder of the program.  It resulted in
output to a data file that eventually contained 40,000 data points from
which the video simulation was to be created.  We ran out of time.
However we were far enough along that we were permitted to keep the DEC
5000/25 Workstation that was provided for us to do our work.

        Believe me, bridges are NOT SIMPLE STRUCTURES.  They are not easy
to analyze.  It took my students and I two months to understand what the
equations represented.  We were lucky that we had a project advisor from
the Civil Engineering Department at CMU that was able to provide enough
information to keep us moving along.

        So, probably the easiest was to analyse the bridge is to find a
Civil Engineer that is willing to give you access to some of his or her
structural analysis software.

Ed Henke
George Westinghouse HS
Pittsburgh, PA