大型结构地面模态试验测点选择与优化

为了解决一般传统的优化算法对于大型结构测点的优化配置的失效问题,针对传统优化算法的缺点,对大型结构的模型缩聚技术做了进一步的改进和完善。引入了一个反映高阶模态贡献比例的权重系数,由此提出了一种基于有效独立法的混合优化算法:基于有效独立法的加权平均模态应变能系数法。经火箭仿真实例对上述方法及Guyan缩聚基于模态应变能系数有效独立法、改进后Guyan缩聚基于模态应变能系数有效独立法得到的测点配置效果进行了比较。结果表明:提出的测点优化算法有效地防止了测点分布聚集现象,而且都最大可能保证了所有模态应变能的贡献和较优布置测点具有较大能量的要求,并用实际的GARTEUR飞机模型对该方法进行了模态试验验证。试验结果表明,该算法保证了监测模态的完整性和线性无关性。

Structure of Large Ground Modal Test Node Selecting and Optimizing Method Research

Model reduction of large-scale structures are improved and a weight coefficient reflecting the contribution proportion of a higher-order model is introduced in light of the shortcomings of conventional optimization algorithms, with the aim to solve the problem that conventional optimization algorithms do not serve the optimized distribution of large-scale structure observation stations. One hybrid optimization algorithms is proposed based on the effective independence method. The observation point distribution effects drawn from the modal strained energy coefficient method based on the effective independence weighted average are compared with that drawn from the effective independence methods for Guyan reduction based on modal strained coefficients and the respectively improved ones through a rocket simulation experiment. Results show that the algorithms effectively avoid the emergence of concentrated observation stations, and ensure the contribution of all modal strain energy and requirements that the better-arranged observation station has much more strained energy. Modal tests based on the method are carried on real GARTEUR plane, which show that the algorithms guaranteed the completeness and linear independence of monitoring mode.