Research on the Strength members of Ship Structure under the Quasi-Static Loads and the Dynamic Loads

为防止船体结构受力构件的严重破坏，对船体横向结构的屈曲强度、塑性破坏、随机载荷下的疲劳强度和冲击强度进行了研究。1)建立了简支矩形板在双向压缩、弯曲和剪切五种载荷作用下的弹性屈曲相互作用方程。与Lloyd‘s Register和Det Norske Veritas提出的相互作用进行了比较。结果表明，本研究中新的交互作用方案在安全方面产生了更好的准确性。2)采用矩阵方法对船舶横向结构在准静态极限载荷作用下的塑性倒塌可靠性进行了评估，得出了安全裕度，并成功地应用于某些国家载货条件下的大中型油轮和运矿船。3)扩展了理想结构单元法的功能，使其能够更准确地应用于更广泛的实际结构。还考虑了横向载荷及其与初始缺陷的相互作用。4)提出了一种新的疲劳试验方法，可以在很短的时间内获得随机载荷作用下的S-N图。并与美国能源部规范和AWS规范计算的对接和角焊低碳钢强度图进行了比较。5)为了估算波浪中作用在船体壁板上的冲击压力，进行了参数试验，研究了壁板刚度对冲击压力的影响。提出了一种估算板件在冲击压力作用下的动力响应的新方法。

In order to prevent some serious damages of the strength members of ship structure, research on the buckling strength, on the plastic collapse of transverse structure of ship, on the fatigue strength under random loading and on the impact strength were carried out. 1) A new elastic buckling interaction equation for simply supported rectangular plates was proposed when the plates was subjected to five loads components, such as compression and bendings in two directions and shear. A comparison was made with interactions proposed by Lloyd's Register and Det Norske Veritas. The results indicated that the new interaction proposal in this research yielded better accuracy in safety side. 2) Reliability assessment of the plastic collapse of ship transverse structure was evaluated under quasi-static extreme loads to generate the safety margin, using a matrix method and was successlly applied to the large and medium size tankers and ore carriers under some national loading conditions. 3) The capabilities of an ideal structural units method were extended so that they can be accurately applied to a wider range of actual structures. Lateral load was also considered and its interaction with initial imperfections was taken into account. 4) A new fatigue test method was proposed, which was able to obtain S-N diagram under random loading during a very short period of time. A comparison was made with strength diagram calculated using DOE guidance and AWS code for butt and fillet weld mild steel. 5) To estimate the impact pressure acting on the panels of ship in the waves, some parametric experiments were carried out to investigate the effects of the rigidity of the panel on the impact pressure. And a new method to estimate the dynamic response of the panel under impact pressure was developed.