Investigation of the binding component type effect on the mechanical characteristics of polymer composite materials

The superstructures of carrier ships have been made of shipbuilding steel for many years. Nowadays, the trend of using lightweight shipbuilding materials such as polymer composite materials (PCM) is making progress. This is because such materials provide mass reduction of structures and cut down the maintenance expenses during the ships operation. The research object is light ship superstructures made of PCM fitted on carrier ships with metal hulls. In this paper, the strength characteristics of PCMs and the cyclic durability of PCM samples with steel grip are experimentally investigated. The study of the durability of PCM samples is carried out on an experimental setup under loading conditions corresponding to the tension state of superstructures while operating at sea. The purpose is to study the effect of the type of binder (rosin) on the ultimate strength of PCM in tension, compression, and three-point bending as well as on the cyclic durability of ship superstructures made of PCM. To achieve this goal, three groups of PCM samples (A, B, C) were made and tested. They were reinforced with EMC-600-1250-E glass mat using Yarkopol-110 polyester rosin (group A), Crystic VE 679 PA vinyl ester (group B), and epoxy ED-20 (group C) as a binders. The results of the tests carried out show significant effect of the binder type on the ultimate strength of PCM in tension, compression, and three-point bending. The ultimate strength of PCM with polyester rosin is greater than that of the same materials using vinyl ester and epoxy rosins. The study of the cyclic durability of PCM indicates that the best indicators of cyclic durability were found in samples with vinyl ester resin. The samples with polyester and epoxy rosins are on the second place. The data obtained make it possible to establish the equations of the maximum stress endurance from the number of cycles to failure for each group of samples which is the basis for predicting the cyclic durability of lightweight ship superstructures made of PCM.