Research and development of a digital design system for hull structures

Methods used for digital ship design were studied and formed the basis of a proposed frame model suitable for ship construction modeling. Based on 3-D modeling software, a digital design system for hull structures was developed. Basic software systems for modeling, modifying, and assembly simulation were developed. The system has good compatibility, and models created by it can be saved in different 3-D file formats, and 2D engineering drawings can be output directly. The model can be modified dynamically, overcoming the necessity of repeated modifications during hull structural design. Through operations such as model construction, intervention inspection, and collision detection, problems can be identified and modified during the hull structural design stage. Technologies for centralized control of the system, database management, and 3-D digital design are integrated into this digital model in the preliminary design stage of shipbuilding.

Sequence optimization of hull structure assembly based on prediction of welding deformation

Optimization of assembly process is significant for ship construction, thus reducing the time and related costs of construction. Welding Structure Deformation Analysis （Weld-sta） was used to predict welding deformation of a hull block. After the reliability of simulation was proved by comparing with measured results, four kinds of welding sequences was determined. By considering welding deformation and assembly process with the e]ficieney of automation, decreasing the overturn times （times of turning the erections upside down during welding） and working hours etc, one of the welding sequences is assumed to be the most reasonable one. The study shows this method is very useful in optimal assembly program determination of practical engineering structures.

TLP hull structural design and analysis

Tension leg platform (TLP) has been one of the most favorite deep-water platform concepts for offshore oil and gas field exploration and development. As of now,a total of 24 TLPs have been installed worldwide with 3 more to be installed in the near future and 5 more under design. Most of these installations are in the Gulf of Mexico (GoM). Water depths for these TLP installations range from 150 m to 1 600 m. It is highly expected that China will have her first TLP designed,fabricated,and installed in the very near future. In order to satisfy the need for a unified hull structural design practice,this paper presents the design philosophy of a conventional TLP hull structure with emphases on critical structural components design and analysis methodologies.

Study on Collision Between Two Ships Using Selected Parameters in Collision Simulation

In the present analysis, several parameters used in a numerical simulation are investigated in an integrated study to obtain their influence on the process and results of this simulation. The parameters studied are element formulation, friction coefficient, and material model. Numerical simulations using the non-linear finite element method are conducted to produce virtual experimental data for several collision scenarios. Pattern and size damages caused by collision in a real accident case are assumed as real experimental data, and these are used to validate the method. The element model study performed indicates that the Belytschko-Tsay element formulation should be recommended for use in virtual experiments. It is recommended that the real value of the friction coefficient for materials involved is applied in simulations. For the study of the material model, the application of materials with high yield strength is recommended for use in the side hull structure.