Issue34

R. Citarella et alii, Frattura ed Integrità Strutturale, 34 (2015) 554-563; DOI: 10.3221/IGF-ESIS.34.61 558  model A: e A = 2.05 mm, D m = 64.1 mm (Fig. 1);  model B: e B = 3 mm, D m = 66 mm. Figure 3 : Mesh and boundary conditions of the coupling for the plane strain problem (symbols in red are representative of normal gap). Figure 4 : 3-lobe polygonal coupling parametric dimensions. The shaft and hub were both made of steel (42CrMo4) with a Young’s modulus E=216000 Nmm -2 , Poisson’s ratio  =0.3 and yield strength  s =800 Nmm -2 . The analysis was carried out under the hypothesis of isotropy, homogeneity and linear elasticity of the material. In Fig. 5 a 2D example of the stress state induced by the combined action of the interference and torque is shown. D ESIGN OF EXPERIMENTS AND ANALYSIS OF THE RESULTS he operating procedure requires the carrying out of several preliminary stages in order to design the experiments: identify the objective functions or performance parameters to be optimized; identify the control and noise factors and the related levels. This phase involves the definition of the orthogonal matrix, which identifies the combinations of the control and noise factors relating to each simulation. For the design of numerical simulations, an orthogonal type L 4 (2 3 ) matrix was adopted