3.2.3 Main rocker
The main rocker will be a sandwich of two laser-cut aluminium sheets. This gives a
construction that is sti for in-plane forces, but is a lot weaker for out-of-plane forces
that try to bend it. To assure that the rocker is loaded the optimal way, al forces will
have to act in the same plane, called the work plane. This can be achieved by placing the
centre line of the connection rod (pull rod), damper and anti-roll bar connection rod in
the same plane, in neutral position of the wheels.
To construct the work plane, a reference plane is created through the pull rod and an
arbitrary point (the origin). The work plane is also created through the pull rod, but at an
angle to the reference plane. By varying the angle, the orientation of the spring-damper
system can be altered. The angle is set such that the dampers lie in a horizontal plane
to minimize packaging volume, height of the centre of gravity and the risk of hitting the
ground if the suspension bottoms out.
Unlike the URE05, the connection points on the main rocker are all connected via straight
lines, as can be seen in gure 3.4. This way, there is no stress concentration and reduction
in stiness like there is in the kink of the URE05 rocker. Furthermore,
aps are added to
the sides of the rocker. These
aps are bend and welded together to create a semi closed
box with a higher out-of-plane stiness than a pure sandwich construction