摘要
本文报导超声波高温螺栓应力监测仪的研制。换能器用铌酸锂做压电晶体,采用银或金等软金属薄层做衬料的压紧耦合方案,在温度0—350℃和有辐照的条件下能长期连续工作。测量声时采用过零电平检测和时间间隔多次平均的方法及其它多种措施,达到了标准误差只有0.82ns的精度。在实验室里我们按现场的使用情况测定了大量纵横波声时与应力关系的数据,用数据处理的方法去除其中不合理的数据后,用双变量三阶拟合的方法,借助计算机算出应力和声时关系方程的16个系数。正式测量中仪器通过测量螺栓的纵波和横波声时,由纵波和横波声时与应力的这个关系式计算螺栓的应力,实现了大范围里温度(0—350℃)的自动补偿,测量精度优于9.8MPa。
This paper presents our research on the high temperature bolt stress monitor. Lithium niobate was used for piezoelectric material, and gold or silver films were used for coupling material in clamping together method to install the transducer, which can be used at 0—350℃ under radiation for more than two years. Time interval averaging, zero crossing detect and several other ways were used to improve the accuracy. The standard deviation is 0.82ns. We tested the transit time of longitudinal wave and shear wave (TTLSW for short), then examined the data, and deleted the wrong data, so that the computer would use good data to calculate the 16 coefficients of a 3 order equation with 2 variables. This equation is used to calculate the bolt stress from the TTLSW afterwards. The influence of temperature is automatically compensated in the range of 0—350℃, and the accuracy of stress is better than 9.8MPa.
出处
《同济大学学报（自然科学版）》
EI
CAS
CSCD
1991年第4期433-439,共7页
Journal of Tongji University:Natural Science
关键词
超声波
高温
螺栓
应力
监测仪
Ultrasonic
High temperature
Stress
Monitor
