TY - GEN
T1 - Three -dimensional finite element analyses of flexible airport pavements for the next generation of aircrafts
AU - Willis, Michael
AU - Johnson, Dona
AU - Sukumaran, Beena
N1 - Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2006
Y1 - 2006
N2 - With the advent of larger and heavier aircrafts with more complex wheel configurations, current design methods of airfield pavements are becoming inadequate. Current design procedures are typically conducted using a layered elastic approach, which assumes a two-dimensional environment with linear elastic material responses with theory of superposition to achieve the effect of multiple wheel loads. With the release of heavier aircraft with more complicated landing gears, the analysis situation has become more complex. The stress interactions between separate tires is not as simple to model; a two-dimensional model is incapable of modeling the three-dimensional problem of a triple-dual-tandem (TDT) axle used on B-777 and A380 aircraft. This paper documents the use of finite element analyses techniques to determine the failure mechanism in a pavement system under moving aircraft loads. The three-dimensionality of the failure surface under actual wheel loads with wander requires that computationally intensive three-dimensional models be used. The flexible pavement system that is modeled is comprised of a medium and low strength subgrade. The stress-strain response of the material is simulated using an elasto-plastic model. The finite element techniques employed are verified against available failure data from the National Airport Pavement Test Facility (NAPTF) of the Federal Aviation Administration based in Atlantic City. Several conclusions can be drawn from the analysis. The response of pavement structure using elastic properties does not accurately pzedict the pavement response. On the other hand, the elasto-plastic material model is able to emulate the response of pavement material. It is also seen that wander causes greater stresses and strains within the subgrade layer as well as greater upheaval when compared to models that neglect wander. The field of influence is also increased. The analysis which modeled the aircraft landing gear trafficking across the pavement section also indicates that pavements with less than 30 inches of pavement structure over the subgrade results in high levels of stress on the subgrade and adding additional subbase has diminishing returns in improving the pavement performance.
AB - With the advent of larger and heavier aircrafts with more complex wheel configurations, current design methods of airfield pavements are becoming inadequate. Current design procedures are typically conducted using a layered elastic approach, which assumes a two-dimensional environment with linear elastic material responses with theory of superposition to achieve the effect of multiple wheel loads. With the release of heavier aircraft with more complicated landing gears, the analysis situation has become more complex. The stress interactions between separate tires is not as simple to model; a two-dimensional model is incapable of modeling the three-dimensional problem of a triple-dual-tandem (TDT) axle used on B-777 and A380 aircraft. This paper documents the use of finite element analyses techniques to determine the failure mechanism in a pavement system under moving aircraft loads. The three-dimensionality of the failure surface under actual wheel loads with wander requires that computationally intensive three-dimensional models be used. The flexible pavement system that is modeled is comprised of a medium and low strength subgrade. The stress-strain response of the material is simulated using an elasto-plastic model. The finite element techniques employed are verified against available failure data from the National Airport Pavement Test Facility (NAPTF) of the Federal Aviation Administration based in Atlantic City. Several conclusions can be drawn from the analysis. The response of pavement structure using elastic properties does not accurately pzedict the pavement response. On the other hand, the elasto-plastic material model is able to emulate the response of pavement material. It is also seen that wander causes greater stresses and strains within the subgrade layer as well as greater upheaval when compared to models that neglect wander. The field of influence is also increased. The analysis which modeled the aircraft landing gear trafficking across the pavement section also indicates that pavements with less than 30 inches of pavement structure over the subgrade results in high levels of stress on the subgrade and adding additional subbase has diminishing returns in improving the pavement performance.
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U2 - 10.1061/40838(191)2
DO - 10.1061/40838(191)2
M3 - Conference contribution
AN - SCOPUS:33744918300
SN - 0784408386
SN - 9780784408384
T3 - Proceedings of the 2006 Airfield and Highway Pavement Specialty Conference
SP - 13
EP - 24
BT - Airfield and Highway Pavements
PB - ASCE - American Society of Civil Engineers
T2 - 2006 Airfield and Highway Pavement Specialty Conference
Y2 - 30 April 2006 through 3 May 2006
ER -