基于Campbell模型的卡车与防撞柱最大碰撞力修正计算方法

为探究卡车冲击防撞柱过程中的最大碰撞力，开展了63组碰撞数值试验。根据碰撞后卡车变形特征分析，采用卡车等效变形对Campbell模型进行参数修正，提出了卡车与防撞柱最大碰撞力的修正计算方法，并对国内外相关规范建议的最大碰撞力计算方法的适用性进行了评估。研究表明，碰撞后卡车变形沿宽度呈中间大、两端小的不均匀分布。卡车等效变形不仅受卡车碰撞速度影响，还与防撞柱高度和直径、钢管屈服强度和厚度以及基础深度有关。与实车碰撞试验和数值模拟试验得到的最大碰撞力对比表明，《欧规1》附录B建议方法计算结果严重偏小，《欧规1》附录C和《公路规范》建议方法计算结果离散性较大，该文建议方法计算结果更加准确保守，适用于防撞柱结构设计。

MODIFIED CALCULATION METHOD FOR MAXIMUM IMPACT FORCE BETWEEN TRUCK AND ANTI-RAM BOLLARD BASED ON CAMPBELL'S MODEL

In order to study the maximum impact forces of anti-ram bollards subjected to truck crash, sixty-three numerical experiments were conducted to simulate the crash processes. The crash features of the trucks after impact were presented and analyzed. Then, Campbell's model was modified using the truck equivalent crush. Based on the modifications, a new calculation method for the maximum impact force between truck and bollard was proposed. In addition, the applicability of the calculation methods in the domestic and international related specifications was evaluated. The results show that the distribution of the truck crash deformations after impact is not uniform in width, and the crush at the center is larger than that at the ends. Truck equivalent crush is not only influenced by the truck impact speed, but also related to the bollard height and diameter, the yield strength and thickness of steel tube, and the foundation depth. The comparisons between calculated results and experimental results from truck crash tests and numerical simulations indicate that the predictions by the Annex B of Eurocode 1 are much less, the predictions by the Annex C of Eurocode 1 and Chinese code JTG D81-2006 are dispersive, and the predictions by the proposed method are more accurate and conservative. Therefore, the modified calculation method based on Campbell's model can be applied to the design of anti-ram bollards.