固体火箭发动机壳体制造主要采用钢/玻璃钢复合材料,但仍没有有效可靠的方法对其进行无损检测。采用超声导波检测是较有前景的检测手段,针对钢/玻璃钢粘接复合结构中玻璃钢材料参数的多变情况,根据弹性动力学理论,分析超声导波在管道中传播时的传播特性。首先根据给定材料参数计算频散曲线,确定可对该复合材料检测的导波模态;然后依据玻璃钢的泊松比、密度、弹性模量及厚度等材料参数的波动范围,计算出所选模态的群速度频散曲线的变化情况;最后分析结果表明,在检测频段范围内,同一频率下L(0,2)模态的群速度随着材料泊松比、密度及厚度的增大而减小,随着材料弹性模量的增大而增大。
Steel/FRP composite materials have been used in the manufacture of solid rocket motor shell,but still no effective and reliable method for non-destructive testing. Ultrasonic guided wave testing is more promising. For the changing situation of FRP material parameters,according to the kinetic theory of elasticity,the propagation characteristics of ultrasonic guided wave in the pipeline was analyzed. The dispersion curves for a given material parameters were calculated firstly,determined the guided wave detection mode for the composite. And then calculated the dispersion curves changes of the selected mode group velocity based on the fluctuation range of FRP Poisson's ratio,density,elastic modulus and the thickness of the material parameters. The final results of the analysis showed that within the detection frequency range,the group velocity of L( 0,2) mode decreases with the increase of thematerial Poisson 's ratio,density and thickness,increases with the increase of the elastic modulus of the material at the same frequency.