【作者】 徐彬；

【导师】 任慧龙；

【作者基本信息】 哈尔滨工程大学 ， 船舶与海洋结构物设计制造， 2009， 硕士

【摘要】 普通船体一般都具有充分大的抗扭转能力,但当船舶发生碰撞,搁浅或中弹而导致船体结构破损时,船体的抗扭转能力将显著降低,因此,为了提高舰船的生命力,对舰船极限扭转强度研究是非常必要的。本文基于薄壁梁理论对舰船扭转强度和极限扭转强度进行评估。工作的主要内容如下：1.对薄壁梁扭转的相关理论进行研究,分析薄壁杆件在自由扭转和约束扭转时的应力应变关系,并推导出任意剖面扭转中心的确定方法。2.按薄壁梁扭转理论采用数值分析方法计算船体剖面特性,通过迁移矩阵法将船体各截面耦合在一起进行全船扭转强度评估。3.建立有限元模型,对舱段进行扭转强度以及极限扭转强度的有限元分析。4.用本文的基于薄壁梁理论的数值分析方法分别对某船在完整状态和破损状态下进行了扭转强度评估,并以相应的有限元解进行比较验证。5.基于塑性极限分析的下限定理计算船体剖面在极限状态塑性剪流分布,根据船体剖面在极限状态的剪应力分布,计算船体剖面的极限扭矩。更多还原

【Abstract】 The normal ship hull has strong anti-torsion ability, but the anti-torsion ability of the hull will fall observably when the ship structure is destroyed by impacting, stranding or hitting. Therefore in order to improve the vitality of the warship, thinking highly of the ultimate torsional strength of the warship is necessary. The torsional strength and ultimate torsional strength of the warship is evaluated based on the thin-walled beam theory in this paper. The main work is as follows:1. Do research on the corresponding theory of the thin-walled beam torsion. Analyze the relationship between stress and strain of the thin-walled bar under the condition of free torsion and restrained torsion. And also derive the definite method of the arbitrary section torsional center.2. Based on the thin-walled beam torsion theory, the numerical method is used to compute the hull section characteristic. Every variable cross-section is coupled together by migration matrix to evaluate the hull’s torsional strength.3. Establish the finite element model of the ship and analyze the torsional strength and ultimate torsional strength of the cabin by finite element method.4. The torsional strength evaluation of the integrity and the damaged state of the ship is done using the method in the paper. The result is compared with the relevant finite element analysis.5. The plastic shear flow distribution at the ultimate state of the ship section is computed using the lower limit theory based on plastic limit analysis. According to the shear stress distribution of the ship section at the ultimate state, ultimate torque at the section is calculated.更多还原