Avoidance of brake squeal by a separation of the brake ... - tuprints

4.4 Introductory example of a bicycle brake disc optimization
E = 206000 MPa
ν = 0.3
ρ = 7850 kg/m 3
r i = 0.067 m
r a = 0.08 m
h = 0.002 m
r h = 0.00225 m
r min = 0.0715 m
r max = 0.0755 m
d min = 0.008 m
Table 4.8: Parameters for the introductory bicycle brake disc optimization.
the parameters given in Tab. 4.8. Both FE meshes used for the rotor and
the holes consist of 3D isoparametric elements of quadratic shape function
order (C3D20) with 40800 DOF in the plate mesh and 12609 DOF in the
hole mesh fulfilling convergence requirements. Also for convergence reasons,
the parameter κ was chosen to be 10 −6 (see Eq. 3.26). The disc’s boundary
conditions were selected as free at the inner and outer radius, in order to
optimize the bending dominated eigenmodes in this introductory example. 36
regularly spaced holes were considered in the initial configuration exhibiting
a cyclic symmetry, which can be seen in 4.17, a). The resulting configuration
a)
b)
Figure 4.17: a) Brake rotor with a symmetric (dashed, red line) and the optimized
hole configuration (solid, blue line). b) The distances between the first 22 eigenfrequencies
of the optimized configuration (solid, blue line, circular markers) and
the starting configuration (dashed, red line, square markers).
after the optimization, which took 7 iterations with 623 evaluations of the
95