Pseudo-Dynamic Test System Research

Due to the development of the theory and application of seismic test, seismic test has experienced a three stages of quasi-static tests, shaking table experiment and pseudo-dynamic test. The pseudo-dynamic test takes full advantage of the quick calculation of the computer, and a combination of test-related technologies. Thus make the pseudo-dynamic test the most widely used seismic test technology, while drawing on the advantages of quasi-static and shaking table experiment.Pseudo-dynamic test use the computer to solve the dynamic equations of the motion of the structure, change the seismic wave from analog to digital, make seismic wave data to discrete data. At the same time, combine with the hydraulic servo actuator system, to simulate the vibration of the structure under earthquake. One of the major advantages of this method is the direct measurement of the restoring force of the structure without the need to assume the structural rigidity and elasticity, so that it can more accurately study the nonlinear seismic response.This paper describes the principle of the method of the pseudo-dynamic test, focusing on the numerical integration of the pseudo-dynamic test, including the central difference method, explicit Newmark law, Newmark-beta method, corrected alpha-law and high-end single-step integration methods. Has developed the practical pseudo-dynamic test control software with the use of software development tools.Delphi is currently a very popular software development tool. This design uses Delphi, OpenGL and Matlab to develop the pseudo-dynamic test software. Delphi supports multi-threaded programming technique well. The software has a good real-time performance by using multi-threading technology. Use Delphi and OpenGL to program the software. The software has the function to simulate the earthquake response in3-dimensional mode. The software can also be used in one-dimensional or two-dimensional pseudo-dynamic test, and has a variety of test methods to choose, with a greater versatility. The collected data is saved directly to the hard disk and the Access database. By using the powerful statistics and analysis capabilities of the Access database, the data can be analyzed again. This design has a certain practical value.