Optimisation of large complex structures in an early design stage considering accidental loads

“设计师创造，工程师分析”（Erichsen，1989）。这种分离对于当今船舶和海洋结构物的大多数设计和分析任务仍然有效，因为结构设计，即结构部件的尺寸确定及其分析，目前大多独立于其他专业，根据商定的概念设计进行。因此，在定义全局设计参数并从该概念设计导出分析模型之后，执行必要的分析。这种方法被称为“工程分析”。在工程分析中，单独分析的概念设计的基本组成部分可能会被改变，但这些改变对其他方面的影响在大多数情况下是不评估的，因为这种分析是复杂和昂贵的。这阻碍了真正最优的识别，因为修改总是基于前面的，但不一定是最好的，替代品。一个更好的替代方案是根据安全和运营目标确定最佳设计，最终设计取决于每个专业的要求，从而导致新的和目前未知的设计。这种被称为“工程设计”的整体方法需要在所有相关学科中采用高效的分析技术，以快速和重复地评估变化，并确定进一步优化的潜力。然而，OPTICS不能涵盖所有学科，并集中于开发一种有效的结构设计分析方法。这在工程设计的道路上是一个相当大的贡献。此外，OPTICS还考虑了意外负载。如果海洋结构物受到高于结构物设计载荷的工作载荷和/或意外载荷，则其可能失效，并且后果可能是严重的。故障从结构的外部船体内和/或外部上的小裂缝达到将整个结构破碎成部分。因此，我们必须通过设计来防止这种失效，从而在概念设计阶段通过直接的载荷和响应计算来考虑可能的意外载荷和响应。因此，该项目旨在开发一种有效的建模和分析方法，适用于在早期设计阶段优化大型复杂结构（OPTICS），同时考虑意外载荷。

‘Designers create and Engineers analyse’ (Erichsen (1989)). This separation is still valid for most of today’s design and analysis tasks carried out for ship and offshore structures as the structural design, i.e. dimensioning of the structural components and their analysis, is today mostly conducted independently from other disciplines on the basis of an agreed conceptual design. Thus, necessary analyses are performed after the global design parameters are defined and analysis models are derived from this conceptual design. This approach is known as ‘engineering analysis’. In engineering analysis the basic components of a conceptual design analysed individually may be altered, but the influence of these alterations on other aspects is in most cases not assessed, because such analyses are complex and costly. This hinders the identification of true optima, because modifications are always based on the preceding, but not necessarily best, alternative. A better alternative is to identify the optimal design based on safety and operational objectives, whereby the final design depends on the requirements of each discipline leading to a new and currently unknown design. This holistic approach called ‘engineering design’ requires efficient analysis techniques in all involved disciplines for the fast and repetitive assessment of changes and to identify further optimisation potential. However, OPTICS cannot cover all disciplines and concentrates on the development of an efficient analysis method for the structural design. This is a considerable contribution on the path to engineering design. In addition OPTICS takes into account accidental loads. If a marine structure is subjected to service and/or accidental loads that are higher than the loads the structure was designed for, it may fail and the consequences can be severe. Failure reaches from small fractures within and/or on the outer hull of the structure up to breaking the entire structure into parts. Consequently, we must prevent such failure by design and thus account for possible accidental loads and responses already during the conceptual design stage with direct load and response calculations. Therefore, this project seeks to develop an efficient modelling and analysis approach suitable for the optimisation of large complex structures (OPTICS) in an early design stage considering also accidental loads.