PSI - Issue 12

Marco Povolo et al. / Procedia Structural Integrity 12 (2018) 196–203 Marco Povolo/ Structural Integrity Procedia 00 (2018) 000 – 000

198

3

i s

[mm] [MPa] [MPa] [MPa] [MPa]

interface layer thickness

E

elastic modulus

L E T E

longitudinal elastic modulus transverse elastic modulus

G

shear modulus

LT G [MPa]

orthotropic shear modulus orthotropic Poisson’s ratio

[ Kg/m 3 ] [1/°C] [1/°C]

LT 



density



coefficient of thermal expansion

L  T  ut 

longitudinal coefficient of thermal expansion transverse coefficient of thermal expansion

[1/°C] [MPa]

tensile strength

, L rupture  [MPa] , T rupture  [MPa] , LT rupture  [MPa]

orthotropic stress limit, traction l direction orthotropic stress limit, traction t direction

orthotropic stress limit, shear lt

2. Materials and Methods

The procedure adopted in the present work combines numerical analysis and experimental tests in order to set-up the design procedure of a hybrid tube with a low impact of residual stresses and minimum deflection under constant bending moment. This loading condition and the well-defined geometry are specific for the field of application of industrial printing machines. 2.1. Design and materials

Fig.1. Geometric scheme

The total length of the test tube was 900 mm and the external diameter of the metal tube was 75 mm. The design thickness of the composite was 2.2 mm as a compromise with stiffness and functional requirement. The design thickness of the extruded aluminum tube, made in 6082-T6 alloy, was 2.5 mm. Mechanical properties of UD, viscoelastic interface layer, epoxy resin and aluminum alloy are provided in table 2, 3, 4 and 5 respectively. The stacking sequence initially consisted of 6 layers of unidirectional (UD) CFRP prepreg in the axial direction, which is fundamental for guaranteeing performance and for validating the FEA results. The