Design And Performance Analysis Of V-Type Crack Meter

China is one of the countries with the most intense seismic activities and the most serious geological disasters in the world.The losses and casualties caused by earthquakes are the most serious among all the natural disasters in China.Strong earthquakes can cause damage and collapse of various structures,causing huge property damage and serious casualties.In the earthquake rescue site,to ensure the safety of workers entering the ruins site is one of the key tasks of the rescue work.Dynamic change of crack in the ruins of the earthquake site directly reflect the stability of the ruins.By monitoring the dynamic changes of the cracks in the ruins in real time,an alarm is issued before the ruins may collapse,thus ensuring the safety of the rescue personnel entering the ruins.Aiming at the scene environment of post-earthquake rescue,this paper optimizes the traditional fracture meter,and designs a V-type crack meter which can be used to detect the dynamic change of ruins cracks in the process of rescue.In view of the requirements of small size,easy installation and high sensitivity of the crack meter,the beam of the traditional crack meter was optimized to reduce the volume and make its structure compact.The measuring reed was designed into a V-shaped structure for the convenience of installation.In order to meet the requirements of field sensitivity improvement,based on the calculation model of V-shaped crack meter,ANSYS was used to conduct static analysis on the designed reed and wedge plate to simulate the actual working conditions.The results show that the sensitivity of V-type crack meter decline with the increases of angle of wedge plate,the sensitivity of V-type crack meter the decline is slower in the range of 6°~14°,and faster in the range of 14°~28°.When the angle of the designed wedge plate is 14°,the sensitivity of the V-type crack meter is tested experimentally.The sensitivity of the V-type crack meter is 1.16mV/(mm/V),which is 2.3 times larger than that of the traditional crack meter.The error with theoretical calculation is 3.4%,and the result is within a reasonable range.In order to facilitate the field use,a set of signal data acquisition and wireless transmission system for debris cracks is designed with low power consumption devices.