轮印载荷下多跨梁最危险工况分析与优化

  目的  快速、准确地对大量装载方案进行分级，获得对结构设计要求相近或决定结构设计的装载方案，对装载甲板多跨梁结构设计具有重要意义。  方法  提出一种轮印载荷下多跨梁装载方案分级方法。对于给定的多跨梁结构与装载对象，首先整理出可能的装载方案，通过轮印载荷下多跨梁最危险工况分析方法，求解每种装载方案下多跨梁的最大弯矩、最大剪力和最大挠度；然后将这些计算结果作为装载方案的样本特征，通过XB指数与模糊C均值（FCM）算法，将装载方案进行分级。分析三跨梁和四跨梁跨距比、惯性矩比对分级结果的影响。  结果  计算结果表明，不同结构方案多跨梁分级结果并不完全一致，但等跨等刚度多跨梁分级结果用于不等跨距或变惯性矩多跨梁的结构响应计算，与实际最危险工况结果间的误差小于2%。  结论  分析的多轮印载荷下多跨梁装载方案之间的关系可为多轮印载荷下装载甲板结构设计提供参考。

Worst-case analysis and optimization of multi-span beams under multiple patch loading

  Objectives  It is of great significance to classify a large number of loading schemes quickly and accurately, and obtain loading schemes with similar structural design requirements or decide the structural design of multi-span beams.  Methods  In this paper, a classification method for the loading schemes of multi-span beams under multiple patch loading is proposed. For the given multi-span beams and vehicles, the worst-case analysis of multi-span beams under multiple patch loading is used to obtain the maximum bending moment, maximum shear force and maximum deflection of a multi-span beam under all possible loading schemes; then the XB index and fuzzy C-means (FCM) algorithm are used to classify the loading schemes according to the above results. For three-span beams and four-span beams, the influence of the ratio of span and moment of inertia on the classification results is analyzed.  Results  The numerical results show that the classification of multi-span beams with different structural forms is not exactly the same. The maximum margin of error between the results of multi-span beam structures with variable span ratio or variable moment of inertia ratio calculated with the classification of equal span rigidity multi-span beams and actual worst-case results is less than 2%.  Conclusions  The relationships between the loading schemes of multi-span beams under multiple patch loading is analyzed, providing a reference for the design of deck structures under multiple patch loading.