Optimal Elastic Response and Design of Very Large Floating Structure

为了满足日本对平地的需求，超大型浮动建筑物是一个很有前途的解决方案。适合填海的浅水已经填海，而不易填海的深水则必须利用。利用简化的数值模型分析和讨论了千米量级的超大型浮式结构物的一般动力响应特性。模型为弹性地基上的各向异性板或梁。这是一个简单的模型，但给出了一个非常大的浮动结构的弹性响应特性的一般理解和透视。基于该模型的理解，使得利用结构的优点和避免结构的缺点的结构规划和设计成为可能，结果表明结构的固有频率高于结构的固有垂荡频率。弹性模式与空间波激励PAT-…的匹配对于发散共振响应，除了固有频率和波浪频率的重合外，还需要更多的周期。特征长度是由结构的弯曲刚度和恢复力的弹簧常数定义的，是判断结构变形的有效指标。对于波长大于特征长度的波浪，结构相对柔性，在波浪斜率上表现出变形。针对波长小于特征长度的波浪，结构相对刚性，变形小的特点，提出了一种新型浮筒式超大型浮体结构。改进外缘作为控制装置，改善结构整体响应的响应特性。一系列计算证实了改进后的反应。采用分段连接弹性地基上均匀梁解析解的方法，计算了超大型浮式结构物在飞机起降载荷作用下的响应，讨论了飞机与结构相互作用的影响。通过小型碎屑试验模型的试验，验证了计算方法的准确性。从计算结果可以看出，该结构对飞机阻力的净增加很小。较少

A very large floating structures is a promising solution to satisfy the demand for flat land in Japan. Shallow waters suitable for reclamation have been already reclaimed, and deeper waters where reclamation is not easy must be utilized.The general dynamic response characteristics of a very large floating structure in the order of kilometers were analyzed and discussed using simplified numerical models. The models are of an anisotropic plate or beam on an elastic foundation. This modeling is a simple one but gives a general understanding and perspective of the elastic response characteristics of a very large floating structure. Based on the understanding obtained from this model, structural planning and design which utilize the advantages and avoid the disadvantages of the structure become possible.It was shown that the natural frequencies of the eigenmodes are higher than the natural heave frequency of the structure. The matching of the elastic mode and the spatial wave excitation pat … More tern, in addition to the coincidence of natural frequency and wave frequency, is necessary for the divergent resonance response. The characteristic length, which is a useful measure to juddge the deformation of the structure, is defined from the bending rigidity and the spring constant of the restoring force. For waves whose wavelength is longer than the characteristic length, the structure is relatively flexible and shows deformation on the wave slope. For waves of shorter wavelength than the characteristic length, the structure is relatively rigid and shows little deformation.A new pontoon type very large floating structure was proposed. The outer edge were modified and utilized as a control device to improve response characteristics of overall response of the structure. The improved response was confirmed by a series of calculations. The method of analysis used was to connect segmentally the analytical solutions of a uniform beam on an elastic foundation.The response of very large floating structure under take-off and landing loads of aircrafts was evaluated and the effect of interaction between the aircraft and the structure was discussed. The accuracy of calculation method was confirmed by experiment with small clastic experimental model. From the calculation, it can be said that net increase of resistance on the aircraft induced by the structure is very small. Less