作者机构:
[Ding, Ke] Cent South Univ Forestry & Technol, Hunan Prov Key Lab Engn Rheol, Changsha, Peoples R China.;[Xiao, Yanluo] Cent South Univ Forestry & Technol, Coll Civil Engn, Changsha, Peoples R China.
通讯机构:
[Ding, K ] C;Cent South Univ Forestry & Technol, Hunan Prov Key Lab Engn Rheol, Changsha, Peoples R China.
关键词:
glued laminated bamboo;creep;Burgers rheological model;improved Burgers rheological model
摘要:
The proportion of bamboo material used in industrial production has increased year by year. The glue laminated bamboo (GLB) is a kind of bamboo engineering material. GLB can be used in modern buildings, bridges, furniture and other fields. It is necessary to study its mechanical properties, especially its creep properties. In the paper, the short-term creep performance of GLB is studied at four stress levels. At first, the Burgers rheological model (BRM) and the improved Burgers rheological model (IBRM) are used to study the creep properties of GLB. The parameters of the two models are obtained by fitting the experimental data. The results show that BRM is only suitable for the elastic deformation part of the GLB material. But the nonlinear viscosity coefficient is introduced into IBRM, so it can better describe the creep characteristics of GLB. On this basis, IBRM and BRM are used to predict the long-term creep performance of GLB based on the obtained creep parameters. The results show that the prediction error of BRM is large, and the prediction result of IBRM is in good agreement with the experimental data. It shows that IBRM is more suitable to describe the creep characteristics of GLB.
摘要:
制备生态多孔混凝土试件,切片后,采用数字图像处理技术,通过对切片处理方案的选择对比,选取合理的切片图像处理方案;应用PS、MATLAB、IMAGE PRO PLUS、IMAGE J等软件对多孔混凝土试件切片切面进行处理分析,计算试件的图像分析孔隙率,与实测孔隙率比较分析;用数盒子数法计算生态多孔混凝土试件孔隙结构分形维数并建立其孔隙结构特征与分形维数的关系。试验结果表明:各生态多孔混凝土试件的实测孔隙率都不相同,但都在20%~30%的目标孔隙率之间;各生态多孔混凝土试件的分形维数都不相同,说明了生态多孔混凝土孔隙结构的复杂性、不规则性和多样性;分形维数与实测孔隙率密切相关。
作者机构:
[K.Ding; K.F.Zhang] Hunan Provincial Key Laboratory of Engineering Rheology,Central South University of Forestry and Technology;[K.Ding; K.F.Zhang] College of Civil Engineering and Mechanics,Central South University of Forestry and Technology
会议名称:
2014 International Conference on Remote Sensing and Smart City(RSSC2014)
会议时间:
2014-07-27
会议地点:
中国广东深圳
摘要:
Solving the coefficient of wave equation is widely used in many science and technology fields.At present,the general method is Born approximation method.However,because of taking only advantage of the
关键词:
Curvatures of mode shapes;Damage detection;Multi-scale;Wavelet transform
摘要:
The damage detection method based on wavelet multi-scale analysis is presented in the paper. The damage location can be identified by analyzing the multi-scale wavelet transform coefficients of curvatures of mode shapes. The extreme value of wavelet transform coefficients indicates the damage location. But it is difficult to detect the location of defect if the defect is near to the equilibrium position of vibration. In order to solve this problem, we put forward a method which is to add the wavelet transform coefficients of multi modals together. The method can effectively overcome the above problem. Three damage situations of simply supported beam bridge are discussed in the paper. The results show that the peaks of wavelet transform coefficients indicate the damage location of structural. It is possible to pinpoint the damage location based on wavelet multi-scale analysis on curvatures of mode shapes.
摘要:
The damage analysis based on the modal parameters usually need to compare the test data with the computed data by theoretical analysis. In bridge structure damage analysis, it is impossible that the sensors are set at every node. So the test data need to be extended to every node by using interpolation technology. In the paper, three interpolation methods, cubic interpolation method, cubic spline interpolation method and sinc interpolation method, are introduced. Their applications in bridge structure damage analysis are discussed. The experiment results show that the best interpolation method is cubic spline interpolation method. Using the data processed by interpolation technology can well obtain the damage location of bridge.