Research On Measurment Method Of Welding Residual Stress In Steel Basedon Acoustoelasticity Principle

Because the current residual stress measurement methods can not meet the non-destructive, easy operation, high efficiency, high precision measuring actual production requirements to meet the service needs of large engineering structures, stress measurement have been studied for texture effect, which is based on the principle of sound elasticity. This method of can be widely used in the large production of steel, which has the impact of steel texture effect Through a series of experiments carried out to verify. It develops a ultrasound measurement methods, which can be nondestructive, fast and high-precision.In order to use the ultrasonic stress measurement method for steel. This paper analyzes sound resilient elastic equation under non-linear elastic theory which is based on the sound principle and deduces LCR wave in isotropic media and in anisotropic media equation for stress measurement. It lays a theoretical foundation.Measuring stress the need for a measurement system as a carrier,the paper mainly from the hardware and software aspects of the system was set up.LCR according to the propagation characteristics of the waves in the steel, measured critical angle of refraction of the first low-carbon steel, and using the angle design a transceiver integrated,out of double-income type,calibration measurements, three-in-one ultrasonic transducer device; according to functional requirements, incentives to build out by the host computer system, and having an ultrasonic transducer capable of data acquisition, waveform modulation, data synchronization, data storage and computing capabilities of hardware systems;use Lab VIEW application development software, edit out the coordination to achieve emission excitation signal, receiving the ultrasonic feedback signal, the feedback electrical signal conversion and computation, data results of screening, storage and eventual display ultrasonic measurement system software features.Texture Effect for steel stress measurement by ultrasound measurements analyzed the impact of low-carbon steel microstructure and texture of the ultrasound measurements, according to the texture of an impact on ultrasound measurements of the three possible causes directional calibration experiments were used ultrasonic transducer down experiments, setting parameters of these three ultrasonic measurement software viewpoint experimental verification, the experime ntal results show that the use of directional calibration,ultrasonic transducer down, re-set the software parameters of these three methods to reduce ultrasound measurement texture effect is valid.In order to verify the measurement accuracy of ultrasonic measurement system, The welding residual stress of low-carbon steel plate is measured in the ultrasonic system and the measurement results of the ultrasound system are compared with the hole method and the finite element method. The results show that the maximum deviation of ultrasonic measurement is less than 15% of yield strength and the overall average deviation is 10.06% of yield strength. It can be concluded that the ultrasonic method can replace the widely used method of hole in the aspect of stress measuring.