Nanoindentation test integrated with numerical simulation to characterize mechanical properties of rock materials

It is important to determine the mechanical properties of rock materials accurately from the viewpoint of the design, analysis, and modeling of various transportation infrastructure systems. Conventional methods have some drawbacks, including relatively inaccurate measurements, cumbersome testing-analysis processes, and high variability in measurements. A nanoindentation test integrated with a numerical modeling technique has been validated in other fields as an efficient and accurate tool for the characterization of the key mechanical properties of various irregularly shaped materials, such as the rock materials in this study. This paper presents an integrated experimental- numerical effort based on the nanoindentation measurement and finite-element modeling of a representative rock material, limestone. The experimental efforts, including specimen fabrication and laboratory tests, are presented, and the corresponding analyses of test results combined with the finite-element technique and linear interpolation to evaluate the property measurements are discussed. The elastic properties estimated from the nanoindentation test are similar to the simulation results, demonstrating the validity of the test method and modeling approach. The success of the proposed approach should facilitate the better design of mixtures and structures based on the more accurate characterization of the core material properties.