Mechanical behavior of the viscoelastic polymers under two-frequency loads
The topic relevance is due to: the use of highly-filled polymer composites in important aerospace structures and other industries; the action of complex harmonic loadings on structures where highly-filled polymers are used; the need to develop methods of experimental research and to define deformation properties of materials and calculation methods for structures working in extreme conditions.
The aim of this research is to develop methods for conducting the dynamic experiment, to define viscoelastic parameters of highly-filled polymer composites under stationary two-frequency loadings, and to identify the mathematical model for calculating the stress-strain state of viscoelastic aerospace structures.
As a result of this work, nonlinear representations of stress and strain under two-frequency loadings were presented, and polynomials was used to describe dependencies of dynamic modules and loss angles on frequency. A time-temperature superposition was also used for the accounting of the viscoelastic properties on the temperature, and the Fourier series to determine the viscoelastic parameters.
Future work includes developing optimal experimental design, determining material constants, and checking the model adequacy.