Conductive Composite Sensing Film And Measurement For Deformation Distribution

Model test is an important means and effective ways to solve the complexenvironment of deep underground rock, soil structure interaction and stability ofEngineering. So far the content of the physical model tests measure the deformationcharacteristics of rock media, including formation and development of cracks andformation and change process of shear (damage), destruction and deformation fieldevolution of rock (soil) and supporting structures collaborative scope. However, thecontents of the above test results cannot be measured quantitatively analyzed, as thesensor cannot amount the field test, short of deformation test range. Therefore, it isurgent needed to design new sensors and test methods which is flexible, highsensitivity, suitable for large deformation and could capture the amount ofinformation.The paper was study on the basic sensing characteristics of compositeconductivity, stress and temperature sensitivity based on the research of previouswork，research results shows that thin-film sample of100μm thickness,its pull-resistance curves could have good repeatability are one-dimensional linearrelationship under the condition of25%tensile strain and constant or variabletemperature conditions. Analysis founds that the film samples was1.65%of linearity,sensitivity of2.4303,1.16%repeatability error,5.3%hysteresis error. The resultsshow that the conductive composites can be used as an excellent sensing material.On the basis of conductive features, this paper designed a new strain distributiontest system which is consists of sensor array, hardware system and software system.Deformation test sensor array using flexible circuit boards copper electrodes as testelectrode of sensing unit testing with size of10mm×2.5mm,and can be produced andprocessed according to different test requirements, paste on the test suffereddeformation sensing surface energy field and so on; Test hardware system is includingstrobe signal switch part (Implementation of high-speed switching through signallevel switch array) and signal acquisition part (PCI-1713U-BE multi-function analogdata acquisition card); The testing software system including data acquisition andprocessing procedures which was based on virtual instrument software compiledLabview. It can converted voltage date to corresponding strain data according to thecalibration equation.This paper tested the very symmetrical rubber membrane, cylindrical specimens and the distribution of elastic deformation beams under stress conditions using the testsystem. Test results showed that this paper studies the distribution of deformationmeasurement system design program is reasonably practicable, it achieved a dynamicmeasuring surface distribution of dynamic, real-time measurement test system, whichwas lay a foundation for the development of large surface deformation distributedsensing system of structures and materials.