Research On Damage Detection Of Advanced Grid Structure Based On Frequency Response Function Shape

Advanced grid structure is a favorite new structure of the aerospace industry for its highly effective structure form, good impact resistant performance and large strength-w-eightratio. The manufacture technique and research on mechanical property of AGS has beenimproved significantly. The variety of material damage and highly anisotropic struct-ure ofAGS have led to its various and complicated damage style. However, the research workon damage detection of AGS was little. This article worked on the application of two damage detection method on AGS. Firstly, the successful application of modal strain energychange method(MSEC) on AGS is present by simulate model calculation, referring to theresearch work of successful application of strain energy change method on beam and plate;Then, considering that MSEC method is unable to fully detect pressure crack of skin, residual imag FRF shape-based method was applied to damage detection of AG-S based onprevious research work and its capability of detection of rib break, rib dela-mination andskin pressure crack were observed; After that, the factors that affect its capability of damage detection were discussed by simulate model calculation, which revea-ls that changingexciting position and frequency both can improve detection result and noise made detection less accuracy, especially for the detection of skin pressure crack. In the end, validationexperiments were carried out for this method, in which the exciting frequency fitted for real application of damage detection was found.