预张拉CFRP加固简支梁的动力特性分析

采用弹性力学方法分析预张拉CFRP加固简支梁的动力特性,研究各参数对加固梁自由振动特性的影响。首先将简支梁和CFRP沿界面分开,基于二维弹性力学理论对梁进行动力学分析,利用弦理论对预张拉CFRP进行动力学分析,通过界面间应力和位移的连续条件得到频率方程,由行列式搜根法数值计算各阶固有频率,数值结果与有限元软件ANSYS进行了比较,显示出了很好的一致性。研究表明,CFRP的加固效果随层数和预拉力增加而增强。

DYNAMIC ANALYSIS OF SIMPLY SUPPORTED BEAMS STRENGTHENED WITH PRETENSION CFRP SHEETS

The elasticity method was used for analyzing the dynamic characteristics of simply supported beams strengthened with pretension CFRP sheets.The influence of various parameters on characteristics of free vibration of strengthened beams was discussed in detail.Firstly,the strengthened beam was divided into two parts:bare beam and CFRP sheet.The bare beam was studied based on two-dimensional elasticity,and the CFRP sheet was analyzed by the method of string theory.According to the continuity of the displacements and the stresses between the two parts,frequency equation of strengthened beams was obtained.Eigen-frequencies were given by the searching root method of determinant.Excellent consistency of the present solutions and the finite element solutions from the program ANSYS has been observed.The analysis shows that along with the increase of the layers and the pretension force,the reinforcing effect of CFRP on dynamic characteristics of simply supported beams increases.