摘要
为获取弹性导波在螺旋结构中的传播规律,建立了螺旋坐标系下的弹性力学基本方程,得到了螺旋结构中半解析有限元形式的弹性波频散方程.频散计算结果验证了在钢绞线外层螺旋圆杆中弹性导波的L(0,1),T(0,1)和F(1,1)等模态存在频率截止,并进一步计算了圆柱螺旋弹簧和螺旋天线结构的频散中的相速度和能速度曲线.结果表明:a.不同螺旋结构的频散曲线中普遍存在着频率截止和模态分支现象;b.所推导的螺旋坐标系下的弹性力学方程可以满足对螺旋结构的弹性导波频散分析计算;c.钢绞线外层螺旋圆杆的弹性导波能速度频散曲线在中间频段部分与直杆上频散曲线的对应频段部分的特征相近,圆柱螺旋弹簧与同旋绕比的圆环结构之间的能速度频散特征相近;d.不同螺旋天线的结构形式差别较大,其弹性导波频散特性须要根据具体结构特点作具体分析.
To find rules of guided wave in helix,the elasticity governing equations in helical coordinate system was inextensible expressed and a semi-analytical finite element method was applied to calculate dispersion equation of circular helical rod.The dispersion computation results proved that cut-off frequency occured on lower modes of elastic guided wave in outer rod of steel strand,such as L（0,1）,T（0,1）and F（1,1）.Then the phase velocity and energy velocity dispersion curves were numerically calculated for helical cylinder spring and helical antenna.The result shows that：a.cut-off frequency and mode separation in dispersion curves appear generally on different helical structure;b.the equations deduced in helical coordinate system is available for the dispersion calculation and analysis;c.Energy velocity dispersion curve between cylinder helical spring and cylinder loop is similar in middle section,so all similar between outer rod of steel strand and cylinder rod;d.Different helical antenna varies in dispersion curves.
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2013年第1期111-116,共6页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
基金
中国博士后科学基金资助项目(20110491881)
关键词
弹性导波
频散
螺旋
钢绞线
弹簧
螺旋天线
elastic guided wave
dispersion
helix
steel strand
spring
helical antenna
