基于有限缺陷集的钢丝绳电磁探伤仪的断丝检测灵敏度预测方法

A Sensitivity Prediction Method Based on Limit Flaw Set for Evaluating Wire Rope EMT Instrument Testing Capability on Broken Wire

灵敏度是标识钢丝绳电磁探伤仪性能的重要指标,利用标准试样(以下简称标样)进行标定.由于钢丝绳中存在预应力,无法在标样中制作小断口缺陷,因此利用现有的标样方法无法评价探伤仪对小尺寸断丝的检测能力.首先,应用灰色预测理论,研究一种基于有限缺陷集的断丝检测灵敏度预测方法,在现有缺陷集的基础上,通过数据预测扩展出虚拟缺陷;其次,在测井电缆上制作断口宽度集和断丝数量集,构成有限断丝集标样,实验研究该方法对断丝检测系统的有效性.

Sensitivity is an important performance target for wire rope electromagnetic testing instrument,and can be calibrated by means of reference standard.It is very difficult to make little gap flaw in wire rope reference standard precisely due to the stress in wire rope;therefore,an evaluation just covers the larger scale flaws,can not cover the small scale flaw.This paper refer to a novel method to expand the limit flaw set.Firstly,a method of broken wire testing sensitivity prediction based on limit flaw set is presented,which based on the theory of grey prediction.With this method,an virtual flaw is made to expand the flaw set;thereby,the evaluating accuration can be improved with the new flaw set;secondly,a logging cable reference standard with a set of width of gap and a set of quantity of broken wire were made to evaluate the EMT-13 wire rope electromagnetic testing instrument,by which,the effectiveness of prediction method on EMT instrument is researched.