结构静力数学模型的精化

REFINEMENT OF STRUCTURAL STATICAL MATHEMATICAL MODEL

用有限元方法获得的结构初始数学模型受多种因素影响,同真实结构相比存在着误差,直接用初始模型进行破坏载荷与破坏部位预计往往难于准确。重要结构尤其是飞机结构的静力破坏试验需要预估破坏载荷与破坏部位,以便合理安排试验大纲。本文建议从静力平衡方程出发,利用非破坏静力试验结果精化结构有限元初始理论模型,提高应力—应变分析结果的精度,进而提高破坏载荷和破坏部位的预估精度。模拟试验结果证明了本文方法的可靠性和可行性。

The initial mathematical model of a structure discreted by finite element method has a certain error in comparison with real one under some influence. It is frequently difficult to pre-estimate the failure loads and location in a structure under testing based on its initial model. It is necessary to know the pre-estimated failure loads and location in order to reasonably arrange the test plan for a complicate structure , especially for aircraft. In this paper a method for refinement of initial finite element model is presented, which starts with statical equilibrium equation and in which the initial model is updated by means of a matrix transformation using the results of non-damaged static test. The updating procedure is performed only in the error region of the mathematical model. A method for diagnosis of the error region is suggested in the paper. A simulated test example shows that the method presented in the paper is reliable and feasible , which increases the accuracy of the pre-estimated failure loads and location.