筑坝料动力分析中的Bouc-Wen模型及其参数研究

发布时间：2018-11-08 17:20

【摘要】：Bouc-Wen光滑滞回模型因其能够描述动力荷载下的复杂非线性,广泛应用于材料的动力分析。为研究筑坝料在循环加载条件下动剪切模量和阻尼比以及累积变形等复杂动力特性,将Bouc-Wen模型应用于土体,绘制应力应变滞回圈并分析其模型参数;采用参数敏感性分析方法研究Bouc-Wen模型,并对动力试验数据进行数值模拟;讨论模型参数变化对土体应力应变滞回圈及动剪模量和阻尼比的影响。根据国内外筑坝料动力试验数据统计得到筑坝料模量衰减及阻尼比增长的均值曲线,应用MATLAB软件编制遗传算法程序确定模型参数;利用GDS动三轴仪探究糯扎渡土石坝的心墙掺砾土在循环荷载下的累积变形特性,并应用Bouc-Wen模型对循环三轴试验测得的应力应变滞回圈进行数值模拟。基于参数分析和数值拟合结果,本文提出适用于筑坝料的Bouc-Wen模型参数范围;筑坝料动剪模量衰减曲线和阻尼比增长曲线拟合结果均方误差小于0.4%;糯扎渡掺砾土循环三轴试验8个振动周期累积应变试验值与模型预测值分别为1.2%和1.18%。基于本文研究得到的模型参数范围,Bouc-Wen模型可以有效地模拟筑坝料动模量阻尼和累积变形特性,为筑坝料动力分析提供帮助。
[Abstract]:The Bouc-Wen smooth hysteretic model is widely used in the dynamic analysis of materials because of its ability to describe the complex nonlinearity under dynamic loads. In order to study the complex dynamic characteristics of damming materials under cyclic loading, such as dynamic shear modulus, damping ratio and cumulative deformation, the Bouc-Wen model is applied to soil mass, the stress-strain hysteresis loop is drawn and its model parameters are analyzed. The parameter sensitivity analysis method is used to study the Bouc-Wen model and the dynamic test data are numerically simulated, and the effects of the model parameters on the stress-strain hysteresis loop, the dynamic shear modulus and the damping ratio are discussed. According to the dynamic test data of damming materials at home and abroad, the average curve of modulus attenuation and damping ratio increase of dam materials is obtained, and the model parameters are determined by genetic algorithm program compiled by MATLAB software. The cumulative deformation characteristics of gravel soil in the core wall of Nuozhadu earth-rock dam under cyclic load were investigated by using GDS dynamic triaxial instrument. The stress and strain hysteresis loop measured by cyclic triaxial test was simulated numerically by using Bouc-Wen model. Based on the results of parameter analysis and numerical fitting, this paper presents the parameter range of Bouc-Wen model suitable for damming materials, the mean square error of the fitting results of dynamic shear modulus attenuation curve and damping ratio growth curve of damming materials is less than 0.4 and the mean square error is less than 0.4. The accumulative strain values of eight vibration cycles in the cyclic triaxial test of Nuozhadu mixed gravel soil are 1.2% and 1.18%, respectively, and the predicted values of the model are 1.2% and 1.18% respectively. Based on the range of model parameters obtained in this paper, the Bouc-Wen model can effectively simulate the dynamic modulus damping and cumulative deformation characteristics of damming materials, and provide help for dynamic analysis of damming materials.
【作者单位】：大连理工大学海岸与近海工程国家重点实验室;
【基金】：国家自然科学基金面上资助项目(51179024;51379029)
【分类号】：TV41

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