Application of the Time–Temperature Superposition Principle to Predict Long-Term Behaviour of an Adhesive for Use in Shipbuilding

Abstract

The use of adhesives in the marine sector is rather limited at the time being, but their use in specific areas of the ship would be an advantage due, among other things, to their low weight and low stress concentration along the bonding joint. The aim of this work is to predict the long-term behaviour of the material, as this is a critical factor when using adhesive as a bonding method in ships, since its durability must be guaranteed throughout a previously defined life cycle. This can be predicted by applying the time–temperature superposition principle (TTS), which involves carrying out a test at different temperatures for each specimen, considerably reducing the test time. Two types of experiments have been carried out according with operation modes in dynamic mechanical analysis (DMA): a dynamic frequency sweep and a stationary creep test under constant stress, to check the behaviour of the adhesive under both dynamic and sustained loading. The master curve for the frequency study will be constructed in such a way as to cover the whole range of relevant vibrations that can occur on the vessel, while that for the creep test the curve obtained covers a range of 25 years, which is usually used as the minimum service life in shipbuilding. For both, a temperature range from room temperature to the maximum operating temperature of the material established by the manufacturer shall be studied.