基于回弹速度的硅橡胶贮存老化寿命评估OA

Aiming at the aging problem encountered in the storage of solid rocket motor sealing devices,a kinetic equation using rebound velocity as the aging characteristic index was established to evaluate their storage life.Taking pre-compression amount and aging temperature as variables,permanent compression set and rebound velocity as characterization parameters,thermal oxidative aging tests of silicone rubber specimens were conducted.The variation rules of the aging characteristic indices(permanent compression set and rebound velocity)with aging time under different aging temperatures and pre-compression amount were obtained respectively.Based on the Arrhenius equation,the regression equation between the aging reaction rate constant and aging temperature was established.Kinetic equations of two aging characteristic indices and aging time were constructed respectively,and the predicted storage lives of the silicone rubber under different pre-compression were compared.The results indicate that at the same aging time and pre-compression amount,higher aging temperature leads to a larger permanent compression set rate and a lower rebound velocity,and the change rate of both parameters over time is fast at first and then slows down.At pre-compression amount of 20%,30%,40%,and 50%,the room-temperature storage lives predicted using the rebound velocity as the index are 21.85,20.82,14.91,and 11.26 years,respectively;under the same operating conditions,the room-temperature storage lives predicted using the permanent compression set as the index are 24.79,22.71,17.71,and 13.45 years,respectively.This demonstrates that rebound velocity is a more sensitive aging evaluation index and can provide safer life prediction results,which is of practical engineering significance for reliability evaluation of sealing devices.