Analysis On Vibration Frequency Response Of Rigid Pavement In Conditions Of Aircraft Taxing

Civil aircraft need a long distance on the runway during take-off and taxiing, whicheffected by some factors, for example roughness of pavement, will have a greater impact onthe runway surface so that the strong vibration appears on the pavement, a series of vibrationsignal reflects the dynamic response of pavement. This article is completed under supportingof National Science Technology Foundation and National Supercomputer Center in Tianjinand PERA Global. By theoretical analyses and MATLAB and considerable finite elementsimulations, the analysis has been accomplished on the frequency response and mechanicalbehavior of pavement structures under aircraft random load. The result of this study providestheoretical basis for the design and the evaluation of carrying capacity of runway. The specificwork and achievements are as follow:1. After comparing the various types of roughness incentive model, and establishing therelationship between IRI and PSD.The simulation work is completed based on trigonometricseries synthesis method and pavement roughness evaluation index corresponding to theroughness.2. By combining the dynamics with vibration theory, aircraft-pavement vibration modeland equation are established, during which many factors including roughness, the aircraft lift,configuration of landing gear etc. are considered. This equation can emulationally analyzecharacteristics of the random excitation.3. Considering roughness of pavement produced and that random load is added to finiteelement models of ANSYS, the process of moving load of aircraft is simulated. This approachallows the response of pavement system closer to actual conditions and improves the accuracyof model.4. Under the effect of moving load of aircraft, dynamic displacement, acceleration, stressand stain are calculated and analysed. At the same time, when moving load stays differentlocations, different dynamic response parameters changing with depth is established, whoselaw is analysed. The result identifies dynamic response feature of pavement structure initiallywhich provides theoretical basis for the design and maintenance pavement.5. By applying the excitation on the pavement structure, extracting the vibration of model, acquiring frequency spectrum curve by MATLAB and using the manipulated variablemethod, system analyses the effect of pavement structure frequency resulting from structuralparameters and the configuration of landing gear. The results show that vertical signaldistribution was characterized by the transition from high to low frequency, amplitude offrequency curve decreasing with depth, and the thickness and modulus of soil matrix are themain factors to frequency. Besides, the configuration of landing gear has great contribution tofrequency response.6. Non-destructive testing programs without suspending flight about pavement’s strengthare put forward. The new inspection techniques are applied in the airport in Yunnan Province.It proves that the detecting means and theories are feasible and got good project effectiveness.