Prediction of the vibratory properties of ship models with realistic structural configurations produced using additive manufacturing. (September 2020)

• Record Type: Journal Article
• Authors: Grammatikopoulos, Apostolos; Banks, Joseph; Temarel, Pandeli
• Is Part Of: Marine structures. Volume 73(2020)
• Publication Date: 2020-09
• Subjects: Additive manufacturing -- Cellular -- Modal testing -- Structural vibration -- Thin-walled girders; Naval architecture -- Periodicals; Offshore structures -- Periodicals; Architecture navale -- Périodiques; Structures offshore -- Périodiques; Naval architecture; Offshore structures; Periodicals; 620.4162
• DOI: 10.1016/j.marstruc.2020.102801
• Languages: English
• ISSNs: 0951-8339

Abstract

Abstract: The use of flexible ship models to determine the dynamic behaviour of full-scale ships in waves and to compare the accuracy of numerical predictions has increased in the past few years. Segments attached to a flexible uniform backbone of suitable but simple cross section is the preferred solution. Although such models are relatively easy to manufacture with conventional processes, they do not represent accurately the structural detail, for example, of a container ship. The limitations of conventional manufacturing constraints can be potentially overcome by use of modern technologies such as additive manufacturing. Designing detailed elastic ship models requires the determination of dynamic material properties, in addition to the manufacturer mechanical properties. In this investigation, a detailed but easy-to-implement method is developed, and applied to a uniform container ship-like model, to identify the material properties that are relevant to the calculation of the natural frequencies of 3D printed thin-walled structures. It is demonstrated that modal testing of 3D printed specimens, combined with FEAmodelling, can be used to accurately predict the natural frequencies of much more complex thin-walled structures. This method allows investigators to acquire all information necessary during the design stage of 3D printed structures without having to resort to full material characterisation. Highlights: Static and dynamic flexural moduli of 3D printed structures are quite different. Experimentally derived effective dynamic flexural modulus of 3D printed structures. Accurate prediction of the natural frequencies of realistic container ship model structure. This detailed method can be used for any 3D printed complex thin-walled structure.