Development and Field Calibration of Inertial Subgrade Vibrator
Based on a dual-axis inertial vibrating motor,an ISV400 apparatus was developed for simulating train-induced loading on railway subgrade.Considering the dead load of track structure and subgrade layers,the device was calibrated to regulate peak-to-valley stress σd,valley stress σv,and excitation frequency fout by varying the number of eccentric plates Nc,counterweights Na,and power supply frequency fin.Comprehensive field calibration tests for the ISV400 system were conducted to scrutinize the relationship between fout and fin,explore the dependence of σd and σv onfout under varying combinations of Nc and Na,define the stable operating frequency range of ISV400,establish excitation force estimation equations,and propose parameter configuration methods tailored to field dynamic measurements on sub-grades.The findings indicate thatfout is approximately 0.5 times fiu and that motor shaft under-synchronization in case offout falling below 5 Hz will lead to device dynamic instability.Observed σd and σv values are higher and lower,respec-tively,than theoretical predictions based on the principles of eccentrically rotating masses.Furthermore,these discrep-ancies are positively correlated with fout,which is susceptible to resonant effects between 15～25 Hz.Whenfout ranges be-tween 5～15 Hz and Na remains constant,σd-fout curves remain unaffected by Nc,with an upper σd limit of approximate-ly 400 kPa,while the σv-fout curves corresponding to different Nc are parallel to one another.
railway subgradeinertial vibrating motorvibratorcalibration testexcitation force
万方数据
维普
