Determination of Asphalt Concrete Dynamic Properties By Experımental Modal Analysıs And Ansys Model

Abstract: Frequency, damping and mode shapes, which are the dynamic properties of a structural element, can be determined by modal analysis methods by experimental and finite element analysis. Among the non-destructive modal analysis methods, vibration-based experimental modal analysis (EMA) is one of the most widely accepted methods. This technique is based on the excitation of specimens and measurement of the resonant frequencies corresponding to different vibration modes. Thus, it is possible to determine the viscoelastic properties of the specimens. In the impact resonance test, an impact hammer or small steel balls are used to trigger an excitation. Since the resonant frequency of any material depends on its geometry, density, boundary conditions and viscoelastic material properties, the viscoelastic properties of the material can be calculated back from the measured resonant frequency.
The evaluation and characterisation of asphalt concrete is of great importance for more resilient structural design and analysis of flexible pavements. Test methods that can provide an accurate and reliable measurement of the structural properties of the materials used are also of great importance. The methods used should be reliable, simple, fast, repeatable and cost-effective. The use of non-destructive testing (NDT) methods has proven to provide such assessment and characterisation capabilities. In recent years, NDT has been widely used to determine the structural and dynamic properties of asphalt concrete. In this study, EMA analyses were performed on asphalt concrete specimens prepared in circular and prismatic shapes with different properties and resonance frequencies and damping ratios were determined. At the same time, the test specimens were modelled with ANSYS software and the modal parameters were determined and the results were compared.