多网格防阻块护栏系统的冲击响应

防阻块薄壁结构是护栏系统中重要的吸能元件，通过防阻块的优化设计提升护栏防护能力，最大限度地减小对乘员的伤害具有重要的意义。应用有限元软件ABAQUS，建立了单跨多网格防阻块波形梁护栏系统受质量块冲击的有限元分析模型，计算了壁厚分别为2、3和4 mm的多网格防阻块护栏系统的冲击响应过程，分析了3种不同壁厚的防阻块在给定冲击速度下，内能的变化情况。通过对比分析发现:冲击过程中，壁厚2 mm的双网格防阻块最终内能质量比明显高于其他情形，能量吸收能力最强；并且壁厚2 mm双网格防阻块情形的质量块加速度峰值比壁厚3 mm单网格防阻块情形小约47.6%，更有利于乘员安全。此外，根据WSTC曲线，模拟工况下，冲击引起的人体头部减速度均在安全忍受范围内。

Response of multi-grid obstruction block guardrail system under impact loading

The thin-wall obstruction block structure plays a significant role in energy absorbing guardrail systems. Research on the methods to improve the guardrail protection capability and minimize the passenger injury becomes increasingly more important. In this paper, using the commercial finite element software ABAQUS, we investigated the response of the single-span multi-grid obstruction block guardrail systems with three different wall thicknesses crashed by a mass block. The simulation results prove that the two-grid obstruction block with a gauge of 2 mm exhibits the best final internal energy mass ratio and energy absorbing density. In addition, the resultant acceleration peak of the 2 mm two-grid model is about 47. 6％ smaller than that of the 3 mm one-grid model, indicating a better passenger safety performance. According to the Wayne state tolerance curve (WSTC), the deceleration of a human's head is within the safety range for simulation cases. This study provides design guidelines for enhancing a guardrail system's impact resistant ability and safety grade.