摘要
模型确认方法的判断标准是考察包含识别参数的模型对待识别结构进行描述的精确程度。但由于对待识别结构系统的认识不足以及计算效率的考虑,通常会产生识别参数的不当选取问题,导致模型对待识别结构的描述总是存在不完善之处;当这种不完善较显著时,传统的模型确认方法通常会失效。为此,本文结合结构识别问题的求解可采用正则化技术来改善其不适定性的特点,引入不同识别结果θ^所对应目标函数与^θ的范数之间的对应规律作为先验条件,提出了一种基于L曲线的模型确认方法,有望弥补传统模型确认方法的上述不足。以一弹簧-质量系统、BENCH-MARK结构分别作为仿真算例、试验算例,对所得模型进行了确认;结果表明:传统确认方法不能准确指出试验算例的合理模型,而基于L曲线的模型确认方法对仿真算例与试验算例均可指出合理模型;从而证明了本文研究的基于L曲线的模型确认方法的有效性。
In structural identification,parameters to be identified usually can not be selected appropriately due to the absent knowledge of the structure and to the inadequate improvement on calculation efficiency.Therefore,there is always inconsistency between the model and the structure and,when it is rather obvious,the traditional method of model validation often fails.In order to deal with the problem,a L-curve based method of model validation was proposed.In the method the condition under which regularization technique may be adopted to improve the ill-posedness of identification solutions,was exploited and,moreover,the correlation between objective functions of identification results θ^ and norms of θ^ was utilized as a priori knowledge.The proposed method is expected to improve the above mentioned disadvantage of the traditional one.Validation of the given models was carried out by using the L-curve based method,taking a spring-mass system and a BENCHMARK structure as numerical and experimental examples respectively.The results show that the traditional method could not find the best model among the obtained ones in the experimental example,while the proposed method can pick out the best one in both the numerical and experimental example,which proves the validity of the proposed L-curve based method of model validation.
出处
《振动与冲击》
EI
CSCD
北大核心
2011年第11期36-41,共6页
Journal of Vibration and Shock
基金
国家自然科学基金项目(90715014)
国家自然科学基金项目(10902024)
江苏省自然科学基金项目(BK2008510)
航空科学基金项目(20090869009)
关键词
结构识别计算
模型确认
L曲线
structural identification
model validation
L-curve
