螺栓连接接触区域对导波传播特性影响分析OA

Bolt connections are widely used in aerospace,mechanical,and civil engineering,and their fail-ure can significantly impact system reliability and safety.Therefore,online monitoring of bolt preload is crucial.Due to their strong penetration ability,long propagation distance,and high detection sensitivity,ultrasonic guided waves are widely applied in bolt monitoring.However,the interaction mechanism between guided waves and bolt connection interfaces remains unclear.To address this issue,a two-dimensional frequency-domain finite element model is developed and its accuracy is validated through fre-quency sweep analysis,and the optimal excitation frequencies is studied for A0 and S0 modes under differ-ent excitation frequencies.Simulation results show that guided waves undergo mode conversion when interacting with the connection interface,and the energy transmission coefficients of each mode exhibit periodic changes with contact length.At an excitation frequency of 255 kHz,the A0 mode is more sensi-tive to changes in contact length,suggesting that it is suitable for early looseness detection.At 345 kHz,the S0 mode exhibits a longer periodicity,demostrating that it is more suitable for monitoring the entire process from tightening to complete loosening.