Abstract

Current U.S. and Canadian regulations for rear underride guards on large truck trailers do not promote designs with adequate protection in offset crashes. The objective of the current study was to determine whether a quasi-static evaluation could distinguish between underride guards with different performance in offset crash tests. Five different underride guard designs were evaluated in quasi-static testing. These designs were previously tested in 56 km/h impacts with a midsize passenger car with 30 or 50% overlap. Three of the guards exhibited marginally passing performance in the crash test, with car excursion under the rear of the trailer reaching the base of the windshield but stopping prior to trailer-to-dummy contact. The other two designs failed to prevent trailer-to-dummy contact. Two quasi-static test configurations were assessed for their potential to distinguish between the marginally passing and the failing designs: the outboard P1 test in the existing regulation and a new 20-degree-angled test developed using crash test acceleration measurements. In both configurations, the guard designs with marginally passing crash test results demonstrated higher force and energy levels than the designs with failing crash test results. However, the 20-degree-angled test showed greater differentiation between levels of crash test performance while also producing more representative damage patterns. Underride guards that prevented trailer-to-dummy contact in the crash tests sustained quasi-static force levels of a least 100 kN prior to 75 mm of displacement in the 20-degree test. Rear underride regulations could be improved by replacing the outboard P1 test with a 20-degree-angled load applied to the end of the underride guard. This evaluation also could supplement or replace underride guard crash tests conducted by the Insurance Institute for Highway Safety (IIHS).

摘要

目前美国和加拿大对大型卡车拖车的后部底部防护装置的规定并没有促进在偏移碰撞中提供足够保护的设计。当前研究的目的是确定准静态评估是否可以区分在偏置碰撞测试中具有不同性能的防撞保护装置。在准静态测试中评估了五种不同的防钻撞保护设计。这些设计之前在 56 公里/小时的碰撞中对一辆中型客车进行了 30% 或 50% 的重叠测试。三名警卫在碰撞测试中表现略为合格，汽车在拖车后部下方行驶到达挡风玻璃底部，但在拖车与假人接触之前停止。另外两种设计未能防止拖车与假人的接触。评估了两种准静态测试配置以区分勉强合格和不合格设计的潜力：现有法规中的舷外 P1 测试和使用碰撞测试加速度测量开发的新 20 度角测试。在这两种配置中，碰撞测试结果勉强通过的防护设计显示出比碰撞测试结果失败的设计更高的力和能量水平。然而，20 度角测试显示碰撞测试性能水平之间的差异更大，同时还产生更具代表性的损坏模式。在碰撞测试中防止拖车与假人接触的底盘防护装置在 20 度测试中的 75 毫米位移之前保持了至少 100 kN 的准静态力水平。可以通过将外侧 P1 测试替换为施加到防钻撞护板末端的 20 度角负载来改进后防钻撞规定。该评估还可以补充或替代由公路安全保险协会 (IIHS) 进行的防撞保护碰撞测试。