Diagnostic method of space gridding structure node bolt loosening injury

Disclosed is a diagnostic method of space gridding structure node bolt loosening injury. The diagnostic method of space gridding structure node bolt loosening injury comprises that a bolt ball node is modeling elaborately and a structural combination unit model is set up. The diagnostic method of space gridding structure node bolt loosening injury is divided into a plurality of substructures and is numbered according to a way of geometric position continuity according to composition characteristics of the space gridding structure. A structure testing point is optimizely arranged in a sensor mode and sensitivity analysis of a rod piece is carried out by frequency. Numerical value of bolt loosening injury is simulated. A training sample, an input parameter and an output parameter of a neural network is confirmed. An injury sample is input to a generalized regression neural network (GRNN) network B which is training completed. The output is an injury index of the node, namely the injury position is positioned to the existing node. The number of a training sample when the injury is accurately positioned can be greatly reduced. Practicality that the space gridding structure node bolt loosening injury is diagnosed by taking advantage of neural network technology is strengthened. Especially the diagnostic method of space gridding structure node bolt loosening injury has a prominent advantage to a large-scale space gridding structure with a plurality of the nodes.