DescriptionOne truss our group has chosen is Ryde Bridge. Ryde
Bridge is located at Ryde over the Parramatta River. It is a truss
bridge that was designed to replace the previous ferry service
between Church St in Ryde and Concord Road in Rhodes. Furthermore,
it was also constructed with a lift span so that tall ships would
be able to travel through it unimpeded, however, the mechanism for
this capability has been removed. Analysis1. 2D free body diagram2.
Estimation of external loads From the 2D free body diagram:RL =
approximately 45kN of force acting on the bridge. This is because
it counteracts the weight for the bridge (possibly 80 tonnes
including vehicles) as well as the force of the wind acting on the
bridgeRR = approximately 42kN of force acting on the bridge. This
is because it counteracts the weight of the bridge however does not
counter the horizontal component of the force of the wind on the
bridge.Force of wind = approximately 7kN of force actin on the
bridge. This is because the bridge is high above the river where
there are greater wind speeds and there are no obstacles that could
act as wind breakers.Weight of the internal force (including
vehicles) = approximately 80kN of force acting on the bridge. This
is because the weight of the bridge in addition to vehicles on it
will greatly increase the force acting on the supports.3. Types of
supports We believe that there are 2 types of supports on the
truss. These are a pin joint and a roller joint. We assume this
because a bridge, especially the steel components, will expand and
contract during extreme temperatures including expanding during hot
temperatures. To counteract this, engineers will have put a roller
joint on one of the supports so that the bridge can expand without
putting additional force on the supports. The other support will be
a pin joint because it can provide both the vertical components of
the external loads as well as the horizontal components.4. Types of
joints Bolt joints- Throughout the bridge, there are bolt joints
connecting the various components of the bridge togetherWelded
steel joints- On the steel beams, some have been welded together.5.
Estimation of which members are in compression and tensionRepeats
on the other side because of symmetryFirst we calculate the members
around RL: RL
From this graphical solution, the bottom member would be in
tension and the slanted member is in compressionUsing similar
graphical solutions, we determined that the top member of the
bridge was in compression.