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摘要: 应用有限元软件ABAQUS对Winkler地基上四边自由单块板在飞机轮载作用下的应力和挠度的收敛性进行了分析, 确定了有限元模型应采用的单元类型、网格密度和平面尺寸。按照贡献面积刚度分配原则, 通过在相邻混凝土板侧面的对应结点设置弹簧单元, 模拟接缝集料嵌锁或传力杆的传荷作用, 建立了板-接缝-基础道面结构体系3D有限元模型, 并对比分析了有限元模型计算的接缝传荷系数与已有回归模型的预估结果。比较结果表明: 在基于ABAQUS的刚性道面有限元模型中, 考虑层间接触时, 各结构层宜采用二次积分单元C3D27或C3D27R, 相应的单元尺寸应不超过板厚的1/2, 模型的平面尺寸需大于4倍相对刚度半径, 接缝传荷作用可采用弹簧单元SPRING2进行模拟, 接缝刚度可按照结点贡献面积进行分配。Abstract: Based on ABAQUS software, the stress and deflection convergences of a slab with four free edges resting on Winkler foundation were analyzed.Appropriate continuum element type, mesh fineness and plane dimension for finite element model of jointed rigid pavement were studied.According to the concept of contributing areas, the stiffnesses of nodes along joint were distributed, and spring elements were set at corresponding points of abutting concrete boards to simulate force transfer among concrete boards.A comprehensive 3D finite element model to analyze the structural response of rigid pavement system was developed and verified.The transfer coefficients of joint loads for the model and a regress model were compared.Comparison result indicates that in the finite element model, second-order element C3D27 or C3D27R is most appropriate when considering interlayer contact.Relevant element dimensions should not exceed half of slab thickness.The maximum plane size of the model should be four times of relative stiffness radius.The element SPRING2 can be adopted to simulate the load transfer of joints in which stiffness are distributed to nodes based on their contributing areas.
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Key words:
- airport engineering /
- rigid pavement /
- finite element model /
- ABAQUS /
- structural response /
- joint load transfer
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表 1 三维六面体单元的基本性质
Table 1. Properties of 3D hexahedral elements
表 2 道面结构和材料参数
Table 2. Structural and material parameters of pavement
表 3 飞机荷载参数
Table 3. Loading data of aircrafts
表 4 实例中道面结构和材料参数
Table 4. Structural and material parameters in example
道面结构层 参数 数值 水泥混凝土面层 弯拉强度/MPa 5.0 弯拉弹性模量/MPa 36 000 泊松比 0.15 厚度/cm 36 水泥稳定碎石基层 回弹模量/MPa 1 500 泊松比 0.25 厚度/cm 30 天然砂粒垫层及土基 反应模量/(MN·m-3) 30 -
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