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交叉口、停车场和长大下坡路段等城市道路受力区域,行车荷载复杂,且加速、制动、转向等不同的车辆行驶状态带给路面极其复杂的受力状态。利用ANSYS进行移动非均布荷载下的路面剪应力有限元分析,并采用解耦的方法来解决轮胎与路面接触的复杂问题,即把轮胎与路面的相互作用分解为2个阶段来模拟。首先把路面简化成刚性面来近似处理,建立轮胎与刚性面接触的静载模型,并通过实测试验对模型进行验证,进而得到接触面的应力分布,然后把该应力结果施加到半刚性路面模型上。该路面模型考虑荷载分布形状和轮胎花纹的影响,采用移动的横、纵都非均布的加载形式,针对不同速度、加速度分析路面最大剪应力的分布规律。轮胎对路面的作用可以产生垂直、横向和纵向3个方向的应力,接触面的横向力会显著影响近路表的路面应力情况。研究结果表明:匀速状态下,路表最大剪应力出现在第2花纹的两侧边缘,比中点处的剪应力大了约50%;减速状态下,路表最大剪应力在中间花纹;匀速状态下,路面最大剪应力出现在距路表约2~6cm的沥青上面层中,比路表剪应力大20%;减速状态下,最大剪应力移动到路表;速度和减速度都会影响路面的最大剪应力,而减速度的变化对剪应力影响显著。
Intersections, parking lots and long downhill sections of urban road force areas, driving load is complex, and acceleration, braking, steering and other different vehicle driving conditions bring the road complex extremely stressed state. The finite element analysis of pavement shear stress under moving non-uniform load was carried out by using ANSYS. The decoupling method was used to solve the complex problem of tire-pavement contact. That is to say, the interaction between tire and pavement was decomposed into two phases to simulate. Firstly, the pavement is simplified to a rigid surface and approximated. The static load model of tire contact with rigid surface is established, and the model is validated through field test. The stress distribution of the contact surface is obtained, and then the stress is applied to semi-rigid pavement model on. The pavement model considers the influence of load distribution shape and tire tread pattern. The distribution of the maximum shear stress of pavement under different speeds and accelerations is analyzed by using moving horizontal and vertical non-uniform loading forms. Tire on the road can produce vertical, horizontal and vertical stress in three directions, the contact surface of the lateral force will significantly affect the surface of the road near the table stress conditions. The results show that under the condition of uniform speed, the maximum shearing stress of the road surface appears on both sides of the second pattern, which is about 50% greater than the shear stress at the middle point. Under the deceleration condition, the maximum shear stress of the road surface is in the middle pattern, State, the maximum shearing stress of the pavement appears in the upper layer of asphalt about 2 ~ 6cm away from the road surface, which is 20% larger than the shearing stress of the road surface. Under the deceleration state, the maximum shearing stress moves to the road surface; both the speed and the deceleration affect the pavement Of the maximum shear stress, and the deceleration changes have a significant impact on shear stress.