Ultrasonic-based Elastic Modulus Test System Research

With the development of social industry,the requirements of materials’ performance such as stiffness and hardness are getting much higher in the consitition of innovative automation equipments.In order to obtain the performance parameters of materials quickly and accurately,the testing technologies are also in the stage of continuous expansion and reform.As the base material in various industrial fields,bars’ elastic modulus is an important index to judge its mechanical properties.Therefore,using advanced testing and electronic technology to test the modulus and select the materials is of great significance to guarantee the stability of equipment and safety of operation.And testing of the elastic modulus also is the basis for new materials’ research and development.In order to measure the elastic modulus of bars accurately and quickly without any damage to the material,a method based on ultrasonic grazing incidence is proposed to detect the longitudinal and transverse acoustic velocities.And a set of digital ultrasonic testing system which takes the FPGA and the DSP as the control cores is designed.The FPGA is mainly responsible for the control of ultrasonic transmitter circuit,automatic gain circuit,high-speed A/D sampling circuit and data preprocessing.The DSP is mainly responsible for the follow-up data processing and realizing the automatic recognition algorithms of ultrasonic characteristic parameters.The USB is used to transfer the processed waveform data to PC,and the C#language is used to design a set of upper computer software.After completed the design of the system,the function and technical indexes of the key parts are verified by the simulation test and experiment.The results show that the system can meet the requirements of high-speed data acquisition,processing and transmission.The degree of automation is improved and the measurement accuracy can be 2%of the systerm,which ensure a good application prospect.