Page 360 - Mechanics of Asphalt Microstructure and Micromechanics

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0.12
0.1
Deformation (mm) 0.06
0.08

0.04
0.02
0
0 100 200 300 400
Cycles
Core 1 Core 2 Core 3
Core 4 Core 5 Average Deformation
FIGURE 10.35 Simulated results and their average deformation for coarse mix.

0.05

0.04
Deformation (mm) 0.03

0.02

0.01

0
0 100 200 300 400
Cycles
Experimental Result Simulated Result
FIGURE 10.36 Average experimental result versus simulated result for coarse mix.

10.3.4 Inverse Approach for Material Characterization
Inverse analysis has been widely used to characterize the material parameters in compli-
cated models. In this section, more details are described because this approach is viable
and flexible in model calibration, especially using simulative tests where boundary con-
ditions are complicated. In the inverse analysis, with the help of numerical simulation
techniques, the unknown parameters are obtained from the actual results of the mea-
surements to infer the optimum values of the model parameters. The goal of the back
analysis is to find the values of the model to best fit the measured data with the simu-
lated data. The advantage of inverse analysis is that the parameters that need to be
identified refer directly to the numerical model used for the predictions and optimiza-
tion studies. To optimize the model parameters, an objective function is defined. The
minimization of the objective function is performed on the basis of a variety of optimiza-
tion schemes. The result of the analysis depends on the selection of the algorithms of
optimization. The trial- and error-method, least-square method, and other optimization