Vibration response of rigid runway under aircraft-runway coupling

Based on aircraft-runway coupled analysis, a 4-DOF model for an aircraft's main landing gear was established, and random loads of the aircraft under excitations of pavement with different planeness were obtained. A 3D finite element model of runway considering joints was established, the aircraft's dynamic loads mentioned above were exerted on the runway. Vibration responses of the runway structure under the random loads were studied, and vibration response laws of the runway at its different structural layers and its soil foundations with different depths were analyzed. The varying laws of vibration responses of the surface layer center and the runway far end with variation of runway soil foundation strength were analyzed. The results showed that in the whole width of runway, the vibration fundamental frequency at surface layer center is basically the same as that at surface layer far end, vibration amplitude varies in a "W" shape; at the same position along runway depth, the vibration fundamental frequency remains unchanged, but vibration amplitude gradually decreases; under the aircraft load given here, amplitude attenuation is concentrated in the soil foundation range of 3-11 m, the amplitude attenuation is only 10% within the range of from surface layer to soil foundation with 3 m depth; when dynamic modulus of soil foundation increases from 90 MPa to 240 MPa, the vibration fundamental frequency of runway increases linearly, but after dynamic modulus of soil foundation reaches 240 MPa, increase in the vibration fundamental frequency slows down with increase in dynamic modulus. © 2021, Editorial Office of Journal of Vibration and Shock. All right reserved.