The deviation between the
natural frequencies obtained using FEM (simulated) and the experimental method was determined using Equation 2:
For Euler-Bernoulli beam theory, the
natural frequencies can be expressed as:
The first step for the use of the proposed methodology in a full scale implementation would be the identification of the
natural frequencies using a standard identification procedure.
In parallel to this experimental activity, an FEA-based modal analysis was performed using a more refined 3D model in order to identify the theoretical
natural frequencies and mode shapes.
Finally, repeat the above steps, and the
natural frequencies and mode shapes of cantilever cylindrical shell with and without hard coating can be gradually calculated out based on the self-written Matlab program, which are listed in Table 3.
As can be observed, as the COP frequencies increase, the
natural frequencies increase as well.
Powerful mathematical tool MATLAB has been utilized to extract
natural frequencies and mode shapes of the cylindrical shell for certain material as well as physical parameters.
The
natural frequencies of the model were carried out using [HBI.sup.1] method.
Bridge
natural frequencies changing with the scour depth: a--X direction (longitudinal direction); b--Y direction (transverse direction)
The
natural frequencies and the mode shapes are measured for the damaged structure.
A damage detection methodbased on
natural frequencies only needs two vibration sensors (or even one acceleration sensor) to obtain the modal frequencies.
Their ratio and the
natural frequencies are different for various rubbers and for different storage and service times.
