The purpose of this article was to determine the failure safety margins of the
front braking system of a Honda CTX700 motorcycle and to perform a substantive
stress analysis on the system, as well as to verify the stresses using FEMAP. It
should be noted that in this finite element analysis (FEA), the connections
between components are modeled using linear-contact connections that exert
forces on adjacent surfaces and are not trivially meshed as one solid with
coincident grids with two different section material properties. The first part
of the work involved accurately measuring the geometry of each part and
three-dimensional (3D) modeling of all components. Measurements were taken via
the trivial methods of using a ruler and caliper, and then the 3D model was
generated in Solidworks by digitizing the geometric parameters. Some parts of
the system were simplified in the 3D model to ensure proper meshing of the
model. Cavities and complex geometries, like fillets and chamfers, were
simplified to avoid excessive computation times. Next, after modeling the
geometry, the individual components (disk, caliper, pad, and brake bracket) were
meshed and their respective material properties were assigned. A fine mesh was
used for the components in order to best capture the geometry and to ensure a
more accurate simulation of the parts. Most components were “Hex” meshed, except
for the more complex geometry of the brake caliper and bracket. For these two
components, load distribution was the main interest due to their bulk size in
comparison to the other components and, as such, were “Tet” meshed with midside
nodes. Material properties of the parts were determined through extensive
research of the components via original equipment manufacturer (OEM) references.
After meshing, the operating loads and boundary conditions were defined and
applied to the model. Boundary conditions were provided while operating loads
were calculated using formulas for disk braking torque and thermal temperatures.
The FEA simulations were performed and the generated stresses were compared and
correlated to the hand-calculated stress levels. The margins of safety (MS) were
finally calculated by comparing the determined stresses against the material
failure strengths. The approach was deterministic in gaining knowledge of what
strength levels the braking system was designed for and accessible to the
public.
