Compared to the free-vibration method, the forced-vibration method is regarded to have the following advantages: low noise level, low spread and high precision of identified results, and wide range of reduced wind speed.
Accurate solution to the free oscillation equation of the shallow reticulated spherical shell was obtained. Then Melnikov function was solved,critical condition of chaos motion was given and the existence of chaos motion was confirmed through the digital simulation phase plans and the Poincare map too.
The scheme of gas-abrasive wear test of turbine compressor blades under free vibration of blades, including at high temperatures, is proposed.
Investigation of Fatigue Damage of 20Kh13 Structural Steel and its Compositions with Fused Coatings by the Free Vibration Method
It is shown that the dynamics of variation of the free vibration frequency of the samples is tightly related to the kinetics of fatigue damage.
Results of an analysis of the possibilities of diagnostics of fatigue damage of pieces from metallic materials and compositions with coatings obtained with the use of the free vibration method are given.
The perturbation can be proportional to any of the free vibration modes.
The maximum error between the test results and the calculated results shown by curves from both the free-vibration and the resonant-vibration tests is less than 6%.
The free-vibration and resonant-vibration tests for three types of stiff samples with a known modulus indicate that the maximum deviation between the actual and the tested value using the modified approach were less than 10%.
The method of multiple scales is used to obtain eigenfunctions of the linear free-vibration modes of the pipe.
Three-dimensional finite-element analysis is carried out to investigate the influence of the partitioning membranes of the brain and the neck in head injury analysis through free-vibration analysis and transient analysis.
In free-vibration analysis, the first five modal frequencies are calculated, and in transient analysis intracranial pressure and maximum shear stress in the brain are determined for a given occipital impact load.