基于模态应变能与频率融合方法的功能梯度铁木辛柯梁损伤识别研究

Study on damage identification of functionally graded Timoshenko beam based on the fusion of modal strain and frequency

基于模态应变能和固有频率融合,提出识别功能梯度铁木辛柯梁损伤的新方法。由功能梯度铁木辛柯梁理论给出有限元计算公式,在此基础上计算得出梁结构的固有频率和阵型模态参数。由模态应变能与固有频率融合构造模态频率应变能的计算公式。基于模态频率应变能变化率,定义功能梯度铁木辛柯梁的损伤识别指标。数值算例表明,模态应变能和固有频率融合的损伤识别方法能够有效识别出结构的损伤单元,并且具有较好的抗噪声性能。

Based on the fusion of modal strain energy and natural frequency,a new damage identification method of functionally graded(FG)Timoshenko beam was proposed in this paper. The finite element calculation scheme was given by way of the theory of FG Timoshenko beam and on this basis the natural frequency and shape modal parameters were calculated. The formula of the modal frequency strain energy was constructed after modal strain energy fusing with natural frequency. Based on the change rate of elemental modal frequency strain energy,the damage identification index of FG Timoshenko beam was defined. Numerical examples indicated that the damage identification method fusing modal strain energy with natural frequency could effectively identify damage elements and had good anti-noise performance.