摘要
进行了5根预应力梁的动力试验,结果表明:预应力梁的固有频率随预应力的增加而增加,这与经典的轴力作用下各向同性材料梁的理论分析结果完全相反.为此,将预应力梁视为各向同性材料梁,采用Ist Opt软件对试验数据进行拟合,得到梁频率计算时的刚度修正公式,并将频率计算结果与试验结果及相关文献上的三个修正公式的计算结果进行了对比分析,结果表明:提出的计算公式用于梁的一阶频率计算时,计算值与实测值误差较小,而且能较好地反映频率随预应力的变化趋势,比已有的修正公式更适用;计算梁的二阶频率时误差稍大,也具有一定的适用性;进行梁的三阶及以上频率的计算时存在较大误差,有待进一步的研究.
Dynamic test of five prestressed concrete beams were carried out. The test results indicate that frequencies of those beams are grown in step with prestress force. It＇s opposite to the analysis of dynamic characteristic of isotropic material beam which was subjected to axial compressive force. So in this paper, considered those beams as isotropic material, the modify methods of stiffness of prestressed concrete beam was proposed by fitted linear regression, then compared the calculated results with the test results and calculated results of other three modify formulas in coherent documentations. It indicates that the error of the first frequency which is calculated by this modified formula is small, it also can reflect the variant tendency between the frequency and prestressed force well, and it is more suitable than other modified method. The error of the second frequency is bigger than first frequency, also is useful. But big error exist in the third and high-order frequency, which is needed further research.
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2007年第2期12-15,共4页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
华中科技大学博士后基金
武汉市建委资助项目
关键词
预应力梁
预应力
固有频率
刚度
prestressed concrete beam
prestress force
nature frequency
stiffness
