Analytical and Experimental Assessment of the Viscoelastic Time-Temperature Superposition Principle for a Thermo-Viscoelastic Wing Spar

摘要

The time-temperature superposition principle is used in the study of viscoelastic materials, as the principle allows for tests to be performed in a shorter amount of time. Past studies show that the superposition is primarily done by using a shift factor. An analytical model for a thermo-viscoelastic beam is created using the elastic-viscoelastic correspondence principle and Duhamel equation of heat conduction. An experiment using an acrylic cantilever beam with a tip mass is conducted to validate the analytical model. The thermal strain of the heated acrylic beam was shown to have a negligible effect on the total strain; however, the mechanical strain was heavily affected by the temperature. The mathematical model outlined had good agreement with the experimental thermoviscoelastic beam in bending. The time-temperature superposition principle is shown to be reliable when comparing two elevated temperatures.