Flexural response of composite coated steel components using the extended finite element method

摘要

? 2022In recent years, there has been new interest in understanding the mechanical failures of the polymer-composites used for fairing the hull and the superstructure of large vessels. On average, around 200 superyachts are launched every year, with about 50 of them presenting failures in their polymer-composite coating schemes. Very little literature data is available in understanding the fracture response of these materials for this particular application. This paper presents a numerical study on the flexural behaviour of three popular particulate polymer-composite materials used as coatings on megayacht vessels using the extended finite element method in Abaqus?. The numerical results have been validated against experiments carried out by the authors and good correlation has been obtained. The use of the correct mechanical properties obtained from mechanical testing of the bulk materials, has yielded accurate predictions of the flexural characteristics of the composite-steel specimens up to failure. Three different coating systems have been evaluated with the methodology outlined in this paper. This study demonstrates that validation of the numerical methods with experimental results creates the opportunity for the development of more parametric studies with a reduced requirement to conduct physical tests. The numerical results correlate well with the experimental results carried out by Prodromou 1. The failure loads were predicted with an accuracy of 20 maximum difference from experiments whereas the deformation was predicted within a range of 12 maximum difference from experimental values. (Differences in the failure analysis results could be attributed to the varying properties of the polymer test coupons, however, validation provides encouraging results). Parameters such as the effect of thickness and the differing properties of the polymer-composites have been discussed. It has been found that coated coupons of low thickness can perform better in terms of deflection, thus reducing the probability of failure in real application. The increase in coating thickness leads to an increase in load carrying capacity and flexural rigidity of the beam as expected. Increased thickness of coating could increase surface stresses hence lead to earlier occurrence of cracking. The modelling procedure captured with accuracy the failure response of the composite under quasi-static loading conditions.