Dynamic Load Identification Wilson-θ Method In Time Domain And PATRAN Secondary Development

According to the load identification theory,the distributed dynamic load of structures can be identified by the function fitted with the generalized orthogonal polynomial, such as a line-dimensional distribution and two-dimensional surface distribution. This paper takes one-dimensional beam and two-dimensional sheet model for example, derive the mathematical model and theory of time-domain identification.The software PATRAN provides PCL language for their users as a good secondary development tools. Based on the above theory, combining with the developed PATRAN interface window for the use of entering the necessary parameters, a dynamic load module of the time-domain identification is embedded and integrated in the software. At the same time, the instructions of the input parameters and operating procedures are illustrated, and the corresponding simulation examples are given respectively to verify the module's operational and accuracy.Frequently used as a numerical algorithm, the Wilson-θmethod can ensure that the results converge when the value ofθis greater than 1.4. According to this, a counter-based method of load identification is obtained by the backstepping of the method of Wilson-θ. What's more, another load identification method was derived from the mode superposition principle and the unit impulse theory, and their recognition accuracy, divergent and anti-noise performance are analyzed by the comparison with the corresponding examples. The results show that both of the methods have better recognition accuracy, convergence and noise immunity compared with traditional method of time domain.