基于车轮-桥面接触耦合特性的铺装层受力分析方法

Mechanics Analysis Method for Deck Pavement Based on Tire-deck Contact Coupling Characteristic

为了解决传统桥面铺装设计方法不能准确反映车轮-桥面接触条件下铺装应力响应的问题,提出了一种基于车轮-桥面耦合作用的分析方法。该方法首先建立精细化轮胎及桥面铺装有限元仿真模型,然后将轮胎和桥面铺装的接触耦合转化为时变的边界条件,并形成每一荷载步的整体有限元控制方程,进一步采用Lagrange乘子法和解耦分析技术得到求解接触压应力的迭代方法。以某大跨径长江大桥为例,分析了不同荷位下接触压应力的分布规律,对比了均布荷载和轮胎荷载2种方式对铺装受力状态的影响。结果表明:轮胎荷载作用下铺装的最大纵向、横向拉应力较均布荷载作用更不利,采用轮胎模型可克服现行桥面铺装设计方法中采用均布荷载偏不安全的缺点。

In order to solve the problem of the imprecise stress response caused by the conventional deck design method under the tire-deck coupling condition, a method based on tiredeck coupling analysis was presented. Firstly, the fine finite element model of the tire and deck system was established. Secondly, the tire-deck contact coupling was converted into the timevarying boundary conditions according to the pavement characteristics, and then the integral finite element control equations were formed for each load step. Thirdly, the Lagrange multiplier and decoupled algorithm were employed to calculate the contact pressure between tire and deck. By taking a steel bridge in Yangtze River for example, the contact pressure distribution rule was obtained under the maximal longitudinal and transversal tensile stress positions. The stress analysis was carried out under tire load pattern and uniform load pattern. Results show that the maximum longitudinal and transversal tensile stresses under tire load pattern are more disadvantageous than those under the uniform load. Therefore the simulation method in the paper is employed to avoid the unsafety led by the conventional deck pavement design method which uses uniform load scheme.