考虑接头参数化的空间桁架轻量化设计

Lightweight design of space trusses considering joint parameterization

提出了一种考虑接头参数化建模的连杆布局优化方法,该建模过程是基于轴线夹角及尺寸完成的。管状接头结构的几何特性由被连接杆件之间的相互位置和尺寸决定,通过将其相对位置转化为接头轴线夹角,将其尺寸转化为接头主管及支管尺寸实现了接头有限元模型的参数化建模。接头结构的空间位置可由被连接件的空间位置转化的轴线交点决定,综上可以实现接头有限元模型的嵌入及整体桁架结构的有限元模型建立。利用基于高斯过程的贝叶斯方法对于桁架连杆布局进行优化设计,同时将制造难度纳入考虑并给出具体的设计方案。数值算例表明,优化方法可有效提高优化目标即结构固有频率。

A layout optimization method of connecting beams considering joints parametric modeling is proposed.The parametric modeling process is based on axis angle and size.The geometric characteristics of the tubular joints are determined by the mutual position and size of the connected beams.The parametric modeling of the joint finite ele⁃ment model is realized by converting the mutual position into the axis angle of the joints and the size into the joint head and branch pipe size.The spatial position of the joint structure can be determined by the axis intersection transformed from the spatial positions of the connected beams.In conclusion,the finite element model of the joint can be embed⁃ded,and the finite element model of the whole trusses structure can be established.The Bayesian method based on Gaussian process is used to optimize the layout of the trusses connecting beams,and the manufacturing difficulty is considered and the concrete design scheme is given.Numerical examples show that the optimization method can ef⁃fectively improve the natural frequency of the structure.