A nonlinear spectral element model for the simulation of traffic speed deflectometer tests of asphalt pavements

Figures & data

Figure 1. Schematic representation of TSD tests of asphalt pavements.

Figure 2. Schematic representation of the 2S2P1D model.

Figure 3. Simulated TSD loading configuration.

Table 1. Structural parameters of the asphalt pavement.

Layers	E	ξ	ν	ρ	l
	MPa	–	–	kg/m^3	m
Asphalt	–	–	0.3	2400	0.1
Base	500	0.05	0.3	2000	0.3
Subgrade	60	0.05	0.3	1600	Infinite

Note: E is the Young’s modulus, ξ is the damping ratio, ν is the Poisson’s ratio, ρ is the density, and l is the thickness.

Figure 4. Simulated complex Young’s modulus versus frequency: (a) absolute value, (b) phase angle.

Figure 5. Comparison between the results of elastic and viscoelastic models: (a) vertical deflection curve, (b) slope curve of vertical deflection.

Figure 6. Contour curves of surface vertical deflection for different models: (a) elastic model, (b) viscoelastic model.

Figure 7. Comparison of vertical deflection curves calculated by different models.

Table 2. Computational requirements for different models.

Models	Number of elements	Computational time	Number of processors	Type of processors
FEM-based	91800	4 h	32	Intel Xeon E5-2620 @ 2.40 GHz
SEM-based	3	2 min	8	Intel i7-7700HQ @ 2.80 GHz

Figure 8. Sensitivity of the slope curve of vertical deflection to loading parameters: (a) magnitude of force, (b) speed of movement.

Figure 9. Sensitivity of the slope curve of vertical deflection to parameters of the 2S2P1D model: (a) static modulus, (b) glassy modulus, (c) exponent k, (d) exponent h, (e) constant ζ, (f) constant β, (g) characteristic time.

Figure 10. Continued.