Updating of bridge finite element model based on optimization design theory

To improve the precision of finite element model and reduce the discrepancy between the theoretical calculation result and test result, the finite element model update technique is used to modify the original finite element model. This arithmetic took the minimization of summation of frequency discrepancy and modal shape displacement as its optimizing goal, set restrictive conditions to parameter modification and frequency change by engineering experience, and ranged model updating to restriction optimization. It was resolved by the optimized iteration of gradient decent method. Simulation proves that the model calculation result is close to the test result after updating. The proposed finite element model updating technology of parametrical bridge based on optimization design theory can be used to dynamic test model update.