Periodic Topology Optimization of Crane Boom Based on Improved Soft Kill Option Method

An improved soft kill option (SKO) method is proposed to achieve the optimization design of tower crane boom. For a better optimization performance, a parabolic weight coefficient is suggested and the displacement constraint is taken into consideration. In order to eliminate the numerical instability phenomena like checkerboard and mesh dependence, element temperature filter function is added into SKO method. Through the optimization data comparison of rectangular cantilever plate, it is verified that the improved SKO method can achieve a better result with more uniform stress and higher efficiency. Based on the dimension and load parameters of QTZ63 tower crane boom, an optimization model is established, and a periodic SKO method is put forward to optimize this model. The optimization result of the crane boom can provide a new thought for tower crane boom design. © 2017, Shanghai Jiaotong University and Springer-Verlag GmbH Germany.

塔式起重机臂架腹杆布局及尺寸优化设计

为实现塔式起重机臂架布局和尺寸的优化,提出了桁架结构拓扑及尺寸两阶段优化设计方法.第一阶段先建立臂架的周期性板梁拓扑优化模型,使用周期性SKO方法对腹板进行连续体拓扑优化,得到优化的腹板拓扑构型,并通过提取主应力路径将优化的腹板拓扑结构转化为离散的腹杆布局;第二阶段以臂架腹杆截面半径为设计变量,臂架柔度为目标函数,材料体积为约束条件建立优化模型,基于Lagrange乘子法和库恩塔克条件推导腹杆截面尺寸优化迭代准则,基于欧拉公式推导了腹杆稳定性约束条件以保证尺寸优化过程中臂架稳定性.数值分析结果表明,该优化方法能有效地减轻臂架结构质量,提高臂架的刚度,减少变形并降低结构应力水平.

塔式起重机臂架周期性拓扑优化设计

为实现塔式起重机臂架桁架结构腹杆的布局优化,提出了基于连续体拓扑优化的桁架结构优化设计方法.首先去除起重臂腹杆,用腹板代替,同时为克服臂架细长难以进行拓扑优化的特点,将起重臂划分为若干个优化周期,建立臂架的周期性板梁优化模型;然后使用周期性SKO(soft kill option)方法对腹板进行连续体拓扑优化,优化中使用温度过滤函数消除棋盘格式现象,得到优化的腹板拓扑构型;最后使用有限单元8-邻域网格模型骨架提取算法得到腹板拓扑的中心骨架进而得到优化的腹杆布局.选取QTZ63塔式起重机最大幅度、最大起重量和最大应力3种典型工况作为优化工况,并考虑起升动载荷、风载荷及惯性载荷进行优化设计.基于3种典型工况,从强度、刚度、稳定性方面对原臂架和优化臂架进行了对比分析,验证了优化方法的有效性.

基于SKO方法的满应力结构拓扑优化设计

自然界的生物结构在自适应生长规律的控制下形成了既没有不承载区,也没有过载区的最优材料布局形态,基于这种自适应生长规律原理的SKO(soft kill option)方法可用于工程结构的拓扑优化设计。深入探讨了基于满应力准则的SKO原理的实现方法,并着重讨论了结构拓扑形态寻优过程中的设计参数、寻优策略等关键技术,以若干典型的设计实例说明了该方法的有效性。