4010声发射仪的改装及其二维定位功能的初步实验
REFITMENT OF THE 4010 ACOUSTIC EMISSION METER AND ITS ABILITY FOR TWO-DIMENSIONAL LOCATION
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摘要: 对仅具有线定位功能的4010声发射仪进行了改装,使之能进行面定位并能实时输出。增加同步时间控制器,使两组线定位器能保证对同一事件进行两个轴向同时定位;改单探头为多探头并联,并且在探头和样品间加声导板,减小定位误差,使非线性定位造成的误差与仪器的分辨精度一致,综合误差为样品尺度的1.5%;用Z-80单板机程控声发射仪和宽行打印机,将两个轴向的定位坐标和样品声发射率(或事件累集数,或能量值)实时打印。用改装后的4010声发射定位仪,在单轴压缩下对板状样品(30015013mm)进行直至破裂的定位实验,结果表明仪器的定位功能理想。同时,AE空间分布表明:于样品破坏前在崩裂型破裂区周围形成明显空区;AE密集区均被宏观张性或压性破裂贯穿;空间分布图象具有明显的阶段性。Abstract: In order to monitor two dimensional location of AE hypocentres and to record the output of the meter, we refitted the 4010 AE meter which has only the ability of location along a line. We added a synchronoue timer which controls two line-location units, and replaced the original single transducer with multitransducers, and put sound-conductive plates between the sample and the multitransducers, which reduce the error of AE location. The precision of the requipped d4010 meter is about 1.5% of sample size. A Z-80 computer controls the refitted 4010 and a typewriter. Records of two-axial location of same AE event with AE rate or AE number or AE energy can be obtained at the same time.The AE rate, strain of sample and locations of AE sources can be recorded using the refitted 4010 when a thin plate sample is compressed upto its failure. The results show: (1) A distinct gap of AE location is observed before failure of the sample; (2) areas of AE hy-pocenter concentration are all cut through by long and big macrocracks; and (3) the space patterns of AE sources are different through stages of loading on the sample.