摘要
为了检测某型固体火箭发动机内部的脱粘缺陷,首先分析了声波在分层介质中的传播模型,发现分层系统的复阻抗将使入射波产生相移;然后对甘油、钢板和绝热层组成的三层媒质系统进行了仿真,得到钢板和绝热层脱粘和粘好两种情形下,反射回波的相位随入射波频率之间的关系,验证了理论分析结果,并发现在某些频率点处脱粘和粘好的相位差最大;对带缺陷的样品发动机展开了实验,在相位突变频率的0.99倍处观察回波信号的相位,结果显示粘接良好的部位的相位都在2.85rad以上且分布比较集中,而脱粘的部位相位基本在2.75rad以下;表明回波信号的相位与粘接状态有密切的关系,相位分析法可以用来检测多层粘接结构的粘接质量。
In order to detect the debond defect inside a certain solid rocket engine, the propagation model of soundwave in the multi--layer system was analysed in the paper. It was found that the complex impedance of the multi-- layer system would shift the phase of the incident wave. Then, a simulation on a triple--layer medium system adhered by glycerin , steel and insulation was carried out, through which the re- lationship between the phase of reflection echo and the frequency of the incident wave was obtained under the circumstances of steel and insu- lation bonded well and debonded respectively, which confirmed the result of the theoretical analysis. It was also found that the phase differ- ence between the debonded area and well--bonded area at some frenqueneies is bigger than at others. Experiments were carried out on the de- fected engines and observed the phase of echo at 0. 99 fold phase hit frequeney. The result shows that the phase of the observation point re- lates to bonding condition of the adhesive joint indeed. In conclusion, the method of phase analysis can he used to detect the adhesive quality of the multi-- layer adhesive joint.
出处
《计算机测量与控制》
CSCD
北大核心
2012年第3期784-785,789,共3页
Computer Measurement &Control
关键词
粘接结构
超声检测
相位分析
adhesive joint
ultrasonic detection
phase analysis
