含缺陷车辆转向桥前梁部件极限承载规律研究

目的 研究车辆转向桥前梁在受损情况下的极限承载规律。方法 对转向桥前梁在破片高速侵彻作用下的破坏结果进行数值模拟研究，确定破片正侵彻转向桥前梁不同部位时的侵彻弹道。对含侵彻缺陷的转向桥前梁承受垂直载荷能力进行数值模拟研究。结果 确定了破片正侵彻转向桥前梁不同部位时的侵彻弹道约为圆形通孔。对于直径为1 cm的圆孔缺陷，当位于非易损区时，前梁达到极限承载时在易损区发生断裂，其极限承载能力约为无缺陷时70%；位于易损区时，前梁达到极限承载时裂纹会经过圆孔，其极限承载能力约为无缺陷时60%。以某典型车辆为例，计算得到前梁易损区圆孔缺陷直径超过1.8 cm时，前梁会在车辆的自重下发生塑性屈服。结论 转向桥前梁部件极限承载能力受缺陷尺寸和位置的影响，缺陷尺寸越大，前梁极限承载能力越小。当缺陷位于易损区时，前梁极限承载能力比同尺寸缺陷位于非易损区时更小。该结果可为转向桥功能失效分析提供参考依据。

Law of Ultimate Bearing Capacity of Front Steering Axle-beam Components with Defects

The work aims to study the law of ultimate bearing capacity of damaged front steering axle-beams. A numerical simulation study was carried out on the damage results of a front steering axle-beam under high-speed penetration of fragments. The penetration trajectory of the fragments penetrating into different parts of the front steering axle-beam was determined. A numerical simulation of the vertical load bearing capacity of the front steering axle-beam with penetration defects was carried out. The results showed that the penetration trajectory of the fragments penetrating into different parts of the front steering axle-beam was about circular through hole. For the circular hole defect with a diameter of 1 cm, when it was located in the non-vulnerable area, the front beam broke in the vulnerable area when it reached the ultimate bearing capacity, which was about 70% of that without defects. When it was located in the vulnerable area, the crack passed through the round hole when the front beam reached the ultimate bearing capacity, which was about 60% of that without defects. With a typical vehicle as an example, it was calculated that when the diameter of the circular hole defect in the vulnerable area of the front beam of the vehicle reached 1.8 cm, plastic yield occurred to the front beam under the dead weight of the vehicle. The ultimate bearing capacity of front steering axle-beams is affected by the size and location of the defect. The larger the defect size, the smaller the ultimate bearing capacity of the front beams. When the defect is located in the vulnerable area, the ultimate bearing capacity of the front beams is smaller than that of the defect with the same size located in the non-vulnerable area. The results can provide a reference for the functional failure analysis of the steering axle-beams.