# Collision Study on New Aluminum Alloy W-Beam Guardrail
## 1 Introduction  
In the event of a traffic accident, W-beam guardrails play a crucial role in effectively reducing vehicle speed, preventing vehicles from veering off the road or into uncoming lanes, thereby significantly reducing the occurrence of secondary accidents [1]. According to statistical data, by the end of 2019, the total length of highway guardrails in China exceeded 570,000 km, with W-beam guardrails being the most widely used [2]. As traffic volume continues to increase, enhancing the protective capability of W-beam guardrails is of paramount importance for ensuring traffic safety. Currently, the primary material used for steel guardrails is Q235 low-carbon steel, but this material has limitations. The galvanization process for anti-corrosion generates wastewater that poses significant environmental pollution. Furthermore, research [3] indicates that the service life of steel guardrails is relatively short, typically around 15 years under normal conditions, and may be further shortened by adverse weather conditions. Al 6061-T6 aluminum alloy is an Al-Mg-Si series alloy, and studies [4; 5; 6] have shown that this material is strain rate sensitive, with significant improvements in yield strength and ultimate load-bearing capacity at high strain rates, enhancing its energy absorption capacity against impact loads, making it an ideal material for impact-resistant guardrails. The safety of highway crash barriers is commonly studied using finite element simulations or full-scale crash tests. [PERSON] et al. [7] introduced the application of the finite element method (FEM) in analyzing vehicle crashworthiness, demonstrating its effectiveness through case studies. [PERSON] and colleagues [8] utilized LS-DYNA for finite element simulation, emphasizing that finite element modeling is the best choice for accuratelypredicting the safety performance of highway steel guardrails. [PERSON] et al. [9] assessed the crashworthiness of basalt-fiber-reinforced polymer beam-column guardrails using LS-DYNA. Subsequently, many scholars [9; 10; 11; 12] have employed the nonlinear finite element software LS-DYNA to evaluate the protective performance of guardrails, considering aspects such as maximum dynamic deformation, three-dimensional acceleration of the vehicle, the energy absorption capacity of the guardrail, and post-collision vehicle guidance. The finite element method provides quantitative indicators for evaluating the safety performance of guardrails with high precision and reliability [13]. This method has been widely applied and has played a significant role in the design, improvement, and optimization of guardrails. Many studies have made significant progress in optimizing guardrails. [PERSON] et al. [14] investigated the hooking effect of posts on vehicle bodies, using guardrail dimensions as design variables and defining a multi-objective optimization problem. The optimized guardrails significantly enhanced collision safety with vehicle bodies, providing new avenues for similar optimization methods. Another study [15] proposed a novel independent W-beam guardrail called \"SWG\" and obtained optimal designs satisfying requirements for different vehicle models through multiple simulation tests. During collisions, the SWG guardrail effectively prevented vehicle hooking phenomena and substantially reduced occupant injuries. Additionally, a study [16] designed a new type of guardrail named \"\(\eta\)-shaped W-beam guardrail (\(\eta\)-WG)\", with its unique \(\eta\)-shaped posts successfully addressing the tire-hooking issue of traditional guardrails, thus improving safety performance. The current study explores the factors affecting the deformation of wave guardrails after a collision based on a simplified theoretical model and optimizes the cross-section of traditional guardrails to enhance their moment of inertia.