Damage Identify Of Spatial Lattice Structure And System Develop

People could not know the structure work condition accuracy and timely, because the Modern engineering structures are large and complicated. The structure maybe presents damage because such reason as natural calamity, tired accumulating and erosion. It's import to find the structure damage timely for avoiding personnel's injured and reducing property loss. And we need a structure damage monitoring and analysis system to reflect the structure work condition in time.The study object is spatial lattice structure in Paper. The whole spatial lattice structure health monitors and analysis system be consist of studying three parts. There is digital signal acquisition, modal identify, and damage identify by BP neural network. First, the structure vibration digital signal acquisition is developed with the virtual instrument technology of LabVIEW. It can acquire 16 channels digital signal at one time as real-time, saving signal data to hard disk and trigger. It have number filter set to reduce the noise influence, and keep the digital signal complete. Second, the modal parameter identify function be developed by GUI of MATLAB. It is consisted of LSCE, RFPM and ERA algorithms. Discard the false modal parameter by drawing steady-state figure. And there is a 3D drawing function to display the result of modal identifies. The modal identify function with friendly graphical user interface and simply operation; show the completion of operating step by step. The modal identify function is validated by a truss model simulation data. Come to the conclusion, the result data from the modal identify is reliable and quick. In the finally, do some study work of structure damage identify by BP neural network. Choose conjugate gradient algorithms as training function, choose the rate of change of natural frequency and modal vector of front 10 orders at a freedom degree as the input of BP neural network, and use the number of nodes of truss as the number of output. It's validated by a truss model simulation also, and identify the damage position and extent by modulate the value of input and output. As a result, use BP neural network to identify damage is feasible.The spatial lattice structure damage monitoring and analysis system in the paper take the advantage of LabVIEW and MATLAB. The structure digital signal is complete, the modal identify result is reliable, and structure damage identify by BP neural network is feasible.