正轨箱梁横向肋的竹子结构仿生学设计

为了使起重机箱梁结构轻量化,以竹子为仿生对象对正轨箱梁横向肋进行了结构优化设计.通过研究竹子结构特征参数的自然分布特性与受力特性之间的关系,发现不同受力截面对应不同的等效节间距;考虑加劲肋间距对结构刚度和强度指标的影响,设定加劲肋极限间距,建立了正轨箱梁加劲肋变间距等稳定性优化策略,结合有限元弹性屈曲分析进行迭代优化,实现了加劲肋变间距等稳定性设计.研究表明:优化求解速率随偏差率增大而增大;仿生箱梁较传统箱梁加劲肋数量由15道减小为10道,两根主梁重量减轻136.12 kg;各截面屈曲抗失稳能力差异减小,同时满足强度和刚度设计要求. 

Bionics Design of Transverse Stiffener in the Upright Rail Box Girder Based on Bamboo Strucure

In order to find a lightweight solution for the box girders of cranes, taking bamboo as the bionics objective, a structure optimization was made for the transverse stiffeners of the upright rail box girder. A study on the relationship between the nature distribution of bamboo structural parameters and its mechanical behaviors reflects that different cross sections correspond to different equivalent distances between two adjacent nodes of stems. The effect of distances between two adjacent stiffeners on the structure rigidity and strength index was then analyzed to set the maximum distances between two adjacent stiffeners, and the optimization strategy was built to make the stiffener be of the changeable distance and same stability. Finally, the iterative optimization of the elastic buckling analysis was done by the finite element method to complete the solution for stiffeners with changeable distances and the same stability. The results show that the optimization speed increases with the deviation rate increasing. As compared with the traditional box girder, the number of stiffeners in the bionics box girder decreases from 15 to 10, which makes the mass of two main girders decrease 136.12 kg. Besides, the bionics box girder has a more uniform critical buckling load on each section, and meets the design requirements in rigidity and strength index.