18.4. Material Properties

The veneer is represented by viscoelastic material behavior while the core is assumed to behave elastically.

18.4.1. Transient Thermal Analysis Material Properties

The following material properties are used for the transient thermal analysis:

Temperature (°C) Conductivity (W/mm °C) Specific Heat (J/kg °C) Density (kg/mm3)
Core
300.004002012914.5402.514E-6
2000.0032543071119.296
5000.0029732381284.875
7000.0032553841347.341
Veneer
300.010005623742.2742.531E-6
2000.006603368947.144
5000.0045601251105.625
7000.0042999031167.299

The thermal contact conductance is 4E-5 W/(mm2 °C).

18.4.2. Static Structural Analysis Material Properties

The following material properties are used for the static structural analysis:

Core

Young’s Modulus (GPa) Poisson's Ratio Density (kg/mm3) Temperature (°C) Coefficients of Thermal Expansion
960.242.514E-6301.019E-5
401.007E-5
509.955E-6
609.848E-6
1009.499E-6
2009.190E-6
3009.689E-6
4001.099E-5
5001.311E-5
7001.975E-5

Veneer

Young’s Modulus (GPa) Poisson's Ratio Density (kg/mm3) Reference Temperature Tref (°C) H/R (° K) *
650.262.531E-6 70046400

* H/R = activation energy / ideal gas constant

Prony Series Shift Function Constants
Gi / G0 τi Fictive Temperature (°C) Weight Relaxation Time (Sec)
0.488441.58E-057500.251.58E-05
0.440030.0001637260.250.000163
0.035760.0038537050.250.003853
0.004870.0080506870.250.008050

Following are the polynomial coefficients for glass and liquid thermal expansion:

α g0 = 10.7510E-6 ppm / °C
α g1 = -2.4208E-8 ppm / °C
α g2 = 5.7267E-11 ppm / °C
α 10 = -39.1180E-6 ppm / °C
α 11 = 1.1526E-7 ppm / °C