结构动力学有限元模型的参数识别误差溯源及正向传递

摘要

The main characteristics and propagating feature of system error and random error were expanded based on classical theory of error precision.A hierarchical positively-oriented propagating model of the error was proposed for complex system and its main properties were deduced,also.By using this,the parameter error produced by parameter identification with a finite element based model was analyzed and the origin of overall error of parameter identification and the influence of subsystem error on the positivelyoriented propagating of the overall error were made clear.The identification error of boundary connection stiffness in a steel truss structure was analyzed with the proposed model and the origin and characteristics of the error as well as the influence of model building error,testing error,and calculation error on parameter identification were pointed out.It was shown by a caluculation example that the model could be applied to analyze the composition of the error and its positively-oriented propagating in a complex calculation model with certain effectiveness and feasibility.To some extent,the proposed model was significant for controlling and forecasting overall error of target parameter.%结合经典的误差精度理论,阐述系统误差和随机误差的主要特点和传递特征,提出一个用于复杂系统的误差分级正向传递模型,并推导模型的主要性质.应用该模型对基于有限元模型的参数识别所产生的误差进行分析.该模型体现参数识别总误差的来源以及子系统误差对总误差正向传递作用和影响.应用分级正向传递模型对某钢桁架边界连接刚度识别误差进行分析,指出误差的来源和特点以及建模误差、测试误差、计算误差对参数识别结果的影响.算例表明,该模型对分析复杂计算模型的误差构成及正向传递具有一定的有效性和可行性,对目标参数总误差的控制和预报具有一定的意义.