基于传递矩阵法的电流变体-砂浆悬臂梁动态特性仿真

利用电流变体作为驱动元件与基体砂浆材料直接复合制成智能悬臂梁结构．调节施加在电流变体上的电压，用瞬态激振的方法测定其在不同电场激励下的自振频率，发现当电场强度超过2kV／mm时，电场变化对复合梁的振动频率有一定的影响，其中对一阶频率的影响最大．在实验研究的基础上，基于传递矩阵法和线弹性断裂力学理论，通过定义等效裂纹深度，建立了含电流变体的砂浆复合悬臂梁的振动模型，并得到理论计算复合悬臂梁频率的特征方程．根据实验数据确定模型的参数，并编制MATLAB程序来模拟含电流变体的砂浆悬臂梁随电场强度变化时自振频率的变化规律．研究结果表明，该模型的模拟值与实验值吻合得较好，说明利用这种方法建立含电流变体砂浆复合结构的振动模型是基本可行的．

Dynamic Characteristics Simulation of Cantilever Mortar Beam with Electrorheological Fluid Based on Transfer Matrices

The vibration property of a cantilever composite mortar beam with an electrorheological fluid gap is investigated through hammering test. Its natural frequencies under different electric strength are analyzed. It is found that the applied electric field has an apparent influence on vibration properties of the composite beam on- ly when the intensity of electric field increases beyond 2kV/mm. The influence of electric field upon the first frequency is more remarkable than that upon the second one. Based on the transformation matrices and the theory of linear elastic fracture mechanics, a vibration model of a mortar cantilever beam with electrorheologi- cal fluid is reconstructed to calculate the eigen-frequencies by defining an equivalent crack depth on the beam. Parameters of the model with various field-strengths and various frequencies are identified with test data and discussed. Modeling is carried out with the MATLAB software to get the relation between the natural frequen- cies of the beam and the intensity of the electric field. The comparison between the experimental data and the predicted values indicates that the proposed model is able to accurately describe the changing of frequencies due to different intensity of electric field.