Three-dimensional finite-element models for more efficient hull design

Abstract

Object and purpose of research. This paper discusses FE models of hull structures for lifecycle support applications involving highly complex equation systems, which makes calculation efficiency an urgent and relevant challenge. The paper contains several case studies of hull stress calculation for a ship in long-term service. Materials and methods. The efficiency of hull analysis is improved by the method of structurization implementing a system approach to the calculations of large mechanical systems. The algorithms of this approach are based on the methods of substructures and superelements suggested by Przemienitcki, Argiris, Meissner and a number of other researchers. Structurization methods enables efficient coordination of engineering efforts, when each expert can not only generate a model of substructure, but also analyse and engineer it with consideration of neighbouring subsystems and without the necessity to recalculate the system as a whole. Comprehensive strength and stability calculations for given fragments are performed with accurate boundary conditions and various design layouts. Main results. Generalized boundary conditions for hull compartments yielded by this study made it possible to estimate their stress-strain state depending on a number of design and technological factors, as well as to predict structural wear effect upon hull stresses and strains at different stages of service life. The study also estimated the effect of various superstructure replacement techniques during ship repair upon structural stability of hull. Conclusion. The approaches suggested in this paper offer comprehensive, efficient and integrated analysis of hull as large mechanical system, considerably reducing the total time of calculations and man-hours required to generate and analyse FE-based hull models, as well as making the collective efforts of hull design, operation and repair experts more coordinated and efficient. These approaches may be recommended for life cycle support applications in marine industry.

Keywords

• hull structures
• engineering analysis
• numerical methods
• fe model
• structurization method
• method of superelements