基于静强度试验的有限元模型修正技术研究

基于静力响应的有限元模型修正技术广泛应用于工程结构的参数识别中,需要解决软件实现、基准数据与目标函数选取,以及参数的灵敏度分析等问题。利用位移响应信息对损伤位置确定的悬臂梁进行了损伤程度的精确识别,对于损伤位置不能确定的情况,通过引入应变约束条件实现了损伤位置与损伤程度的同时确定。作为实际工程算例,将飞机静强度试验得到的位移响应与内力响应作为基准数据,利用模型修正技术确定飞机方向舵有限元模型边界条件。算例比较了不同目标函数和约束条件对修正效果的影响,并通过增加内力响应信息进一步修正了根部约束参数,为计算分析提供了精确有限元模型。

Research on Finite Element Model Updating Technique Based on Static Strength Test

Finite element model updating method based on static response has been widely used in parameter identification of engineering structures.It needs to solve the problem of software implementation,base data and objective function selection,and sensitivity analysis of the updating parameters.Firstly,a damaged cantilever beam whose damage location is known before identification is presented,and the damage degree is identified precisely.Through adding strain constraint,the damaged degree and damage location can be identified simultaneously.As an engineering example,the displacement response and internal force response are regarded as base data,and the boundary condition of an aircraft finite element model is determined by model updating method.The updating effect of different objective function and constraint condition is compared according to this example,and the parameters are further updated by adding internal force response to the objective function.Finally,an accurate finite element model is provided for calculation and analysis.