基于人工蜂群算法的桥梁有限元模型局部刚度修正

Local stiffness correction for finite element model of bridge by employing artificial bee colony algorithm

在保持梁单元模型计算效率优势的前提下,为尽可能提高桥梁结构有限元模型的精度,提出一种基于人工蜂群算法的桥梁结构有限元模型局部刚度修正方法。以某刚构体系斜拉桥塔梁连接处的有限元模拟为例,对塔梁结合局部区域分别建立精细的实体元模型和宏观的梁单元模型。基于实体元模型的自振模态频率和静载响应转角构造目标函数,采用人工蜂群算法对宏观梁单元模型局部刚度参数进行优化和修正。研究结果表明:使用人工蜂群算法修正桥梁有限元模型局部刚度是可靠的,修正后桥梁宏观梁单元模型的静动力学性能更逼近实体元模型;算例中修正后的塔梁结合区域内梁单元刚度增强至修正前的1.09~2.93倍,且塔、梁单元刚度增幅不一。

To improve the accuracy of beam-element-based structural finite element model of bridge as much as possible with the purpose of maintaining computing efficiency,this paper presented a method for modifying the local stiffness of bridge model on the basis of artificial bee colony(ABC)algorithm.The modelling of towergirder binding domain which belonging to a rigid-frame-system cable-stayed bridge was taken into consideration.Macroscopic beam-element-based models for binding domain,as well as fine solid element,were built correspondingly.Static bending response angle at end and modal natural frequency,using data from solid element model as the yardstick,were devoted to establishing target function.Then the parameters that representing local stiffness in beam-element-based bridge model,were corrected by using ABC algorithm to optimize.Results show that it is reliable to use ABC algorithm to correct the local stiffness of bridge finite element model.The improved bridge model with beam element behaves better agreement with the solid element model both in statics and in dynamic property.For the present example,the local stiffness of the beam element in tower-girder binding domain is eventually enhanced to 1.09~2.93 times of that before modification,and the stiffness increment for the tower and for girder differ.