摘要
为了获得可用于大型工程结构减振的新型板式电涡流阻尼结构的阻尼计算公式，进行了理论分析和试验测试。首先，基于匀强磁场和无限板长假定，推导了阻尼系数的简化计算公式，并引入了磁场强度修正系数，综合考虑磁场强度的实际不均匀性和有限板长对阻尼系数计算的影响。然后，提出了一种利用单自由度门式框架测试电涡流阻尼系数的试验方法，并测试了不同铜板厚度、铜磁间隙、磁体间距，以及铜板后是否附加铁板的情况下的电涡流阻尼系数及其变化规律，给出了可用于实际工程的磁场强度修正系数推荐值。研究结果表明：电涡流阻尼系数随铜磁间隙的变化呈负指数关系，且随铜板厚度的增加而增大；电涡流阻尼系数最大值发生在磁铁间距为60％或80％磁体宽度时；铜板后附加铁板可以显著增加电涡流阻尼系数；有、无附加铁板时磁场强度修正系数推荐值分别为0．58～O．67，0．77～O．93，且铜板厚度较小时取较大值，铜板厚度较大时取较小值。
In order to obtain the calculation formula for a novel plane type eddy current damping （ECD）, which can be used to suppress the vibration of large-scale engineering structure, theoretical analysis and tested experiments were carried out. First, a simplified formula was deduced based on the assumptions of uniform magnetic field and infinite plate length, and a correction factor of magnetic field intensity was introduced in consideration of the uneven magnetic field intensity and finite plate length in reality. Then, a single-degree-of-freedom portal frame was developed to test the ECD coefficients and its variations under different copper plate＇s thicknesses, distances between cooper plate and magnets, magnet spacings and the conditions whether there is an iron plate behind copper plate. The value of the correction factor of magnetic field intensity was recommended for realistic engineering applications. The results show that the ECD coefficient varies with distances between cooper plate and magnets as negative exponential function, and increases as copper plate＇s thickness increases; the maximum ECD coefficient can be achieved when magnet spacing is 60% to 80% of magnet width; if there is an iron plate behind the copper plate, the ECD coefficient is dramatically increased; the value ranges of the recommended value for magnetic field intensity correction coefficient are 0. 58 to 0. 67 and 0. 77 to 0. 93 for the condition with and without iron plate set behind the copper plate, larger value should be taken when copper plate is thinner, and smaller value should be taken when copper plate is thicker.
出处
《中国公路学报》
EI
CAS
CSCD
北大核心
2016年第10期46-53,共8页
China Journal of Highway and Transport
基金
国家自然科学基金项目(91215302
51278189)
关键词
桥梁工程
电涡流阻尼
数据拟合
板式电涡流阻尼
阻尼系数
bridge engineering
eddy current damping
data fitting
plane type eddy currentdamping
damping coefficient
