| With the rapid development of offshore wind power industry, offshore wind power farm maintenance vessel demand is increasing correspondingly. At present, the development of some offshore wind power in Europe and the United States is generally used in the maintenance of small ships for offshore wind farm. While the domestic offshore wind farm maintenance work to hire or tug wind installation vessel. Therefore, the design and construction of wind farm maintenance work of the ship has become the urgent need to solve the problem.Compared with monohull and catamaran, trimaran has advantages of good stability and seakeeping performance, high speed and large deck area, so it’s more suitable for offshore wind power farm maintenance work. When the trimaran confront with transverse wave or oblique waves, trimaran will occur transverse bending or torsion, the cross deck withstand large tremendous bending moment and torq ue. The transverse strength and torsional strength is the key technology of structure design. It is important for how to determine the cross deck transverse bending moment and torque more accurately, and ensure the enough strength.In this paper, we chose a high trimaran in offshore wind- farm as the research object and process structure design according to the requirement the overall layout. Main hull is designed by the high- speed monohull ship, the side body is designed by the high speed catamaran; According to reference information and specification recommendations, the design scheme of two different structure are studied, namely mixed framing and full transverse framing scheme, and we draw the basic structure and typical cross section diagram for structural design.Using the finite element software MSC.Patran/Nastran to establish whole ship structure finite element model of the catamaran trimaran, under the combination of longitudinal bending moment, transverse bending moment and torque load, we calculate and analysis 9 kinds of working condition, and get the detailed distribution of stress and deformation of the whole ship. Results show that two kinds of structure stress level is about the same, but the transverse framing quality is light. In consideration of the requirement of the high speed ship heavy, the transverse frame is choose n. For the high stress level of the cross deck area, we adjust its structure and have a new calculation, the results show that the adjustment scheme reduce the stress level.In this paper, the transient dynamic response of the cross deck is calculated and analyzed. According to the result, the large stress area of structure is adjusted, The finite element results show that the effect of the after adjustment scheme is better than that of the original plan.This article research results and some conclusions has a certain reference value for the structure design of small high speed trimaran wind power maintenance ship. and it also can provide a reference basis for structure strength analysis of small trimaran in the future. |
