Effects of manufacturing procedure on unsymmetrical sandwich structures under static load conditions

In recent years sandwich structures have been widely used in marine industry; such reason has lead to the study of mechanical properties of the above mentioned structures through the evaluation of the effects induced by different technological procedures. Therefore, this work presents unsymmetrical sandwich structures realised using both lay up and vacuum bag technology. In order to find a static characterisation of the sandwich structure, firstly flatwise and edgewise compressive tests were performed. Afterwards, a three point flexural test was realised in order to examine the different effects of a load, which has been applied to either one or the other side of an unsymmetrical sandwich structure.Thanks to the above mentioned tests, it has been possible to find out and interpret a number of fracture mechanisms that take place when the load conditions change and/or when the technological procedure used to produce the samples varies. Moreover, a theoretical model capable of predicting the stresses inside the sandwich sample is proposed.

► We study unsymmetrical sandwich structures, realised using both lay up and vacuum bag technology.
► We perform several mechanical tests (edgewise compressive, flatwise compressive and three point flexural tests).
► We investigate the different effect of a load applied either to one or the other side of a sandwich structure.
► We find the fracture mechanisms as a function of the load conditions.
► We conclude by proposing a predictive theoretical model.