摘要
模态识别精度评价贯穿模态识别研究的全过程,但基于单一或少数算例的模态识别精度评价方法存在偶然性,因此提出一种基于结构响应数据库评价模态识别精度的方法。数据库的关键数据是结构的模态参数理论值和结构响应;对于集中质量模型,提出一种基于模态参数构建结构物理模型(质量、刚度和阻尼矩阵),进而计算结构响应的数据库构建方法,并用算例验证了可行性。针对随机子空间法定阶难、虚假模态剔除难的问题,提出一种基于奇异熵增量定阶和稳态图两阶段虚假模态剔除的优化随机子空间法,并利用数据库方法对优化的随机子空间法进行了识别精度评价,结果表明:基于数据库的模态识别精度评价方法可行;优化的随机子空间法频率和振型的识别精度高、阻尼比的识别精度较低。
The evaluation of modal identification accuracy runs through the whole process of modal recognition research,but the evaluation method of modal identification accuracy based on a single or a few examples is accidental.Therefore,a method for evaluating modal identification accuracy based on structural response database is proposed.The key step of database construction is to calculate the structural response based on modal parameters.A database construction method is proposed to construct the physical model of structures(mass,stiffness and damping matrix)based on modal parameters,and then calculate the structural response,and the feasibility is verified with an example.Random subspace legal order is difficult,and false mode elimination is difficult;An optimized random subspace method based on singular entropy incremental order determination and two-stage spurious mode elimination in steady state diagram is proposed,and the identification accuracy of the optimized random subspace method is evaluated by database method.The results show that the method based on database is feasible.The optimized random subspace method has high identification accuracy of frequency and mode shape,but low identification accuracy of damping ratio.
作者
杨志林
罗漪
王海峰
YANG Zhi-lin;LUO Yi;WANG Hai-feng(College of Civil Engineering,Huaqiao University,Xiamen,Fujian 361021,China)
出处
《工程力学》
EI
CSCD
北大核心
2023年第4期116-128,192,共14页
Engineering Mechanics
基金
国家自然科学基金项目(51878302,52078225)。
关键词
模态识别
精度评价
随机子空间法
结构动力响应
结构响应计算方法
状态方程
频响函数
modal identification
accuracy evaluation
random subspace method
structural dynamic response
calculation of structural response
equation of state
frequency response function