# Assessment of Crash Performance of an Automotive Component Made through Additive Manufacturing
## 1 Introduction  
The use of lightweight designs and materials has become ubiquitous in the modern world. The need for improved fuel economy has emphasized the use of lightweight materials and high-strength designs in automotive-component manufacturing. Automobile designers maintain high standards for performance, reliability, cost-effectiveness, competitiveness, and safety. Until a few decades ago, safety was considered important, but not decisive, in the commercial success of a vehicle. Following a dramatic increase in the volume of vehicle traffic, accidents have increased; in 2018, they became the leading cause of death for people between the ages of 5 and 29. As a result, there has been a growing awareness of safety, and it has become a central theme in vehicle design. In recent years, efficient numerical techniques have been developed to accurately simulate automobile accidents and limit the number of physical tests [1]. This has made it possible to hypothesize and analyze a high number of different configurations at the design stage and compare their different structural behaviors [2]. When correlating numerical and experimental data, after conducting simulations, it is possible to highlight the emerging criticalities and find the optimal solution. Before a vehicle can be commercialized, it must pass crash homologation tests using standards dictated by the European Commission. In recent years, autonomous organizations have been set up to carry out these tests of vehicle safety; in Europe, a fundamental testing organization is the Euro NCAP (New Car Assessment Program). These entities attribute a variable number of stars to a vehicle to characterize its safety. The results of the tests carried out by the Euro NCAP are public, which hasled automobile manufacturers to improve active and passive safety. Consequently, there has been a significant increase in the safety of today's vehicles [3]. The tests conducted, which include frontal impact, side impact, impact against a pole, etc., are necessary to characterize the damage suffered by vehicle occupants and pedestrians. Upon completion of the tests, based on various biomechanical parameters detected by sensors placed on mannequins, the Euro NCAP assigns scores in the following categories: adult occupants, child occupants, safety assist, and vulnerable road users. Finally, using a weighted average of the four categories, it assigns a final score of one to five stars. The damage suffered can be slight, but under certain load conditions, limb fractures can be detected, as well as, in extreme cases, deaths among passengers. Appropriate component design is therefore essential to limiting injuries [4]. In recent years, innovative materials have been analyzed to improve the safety performance of vehicles. Composite materials have been studied and introduced in various sports cars, which have excellent mechanical characteristics and a low weight [5; 6; 7; 8; 9], but costs are still high, meaning not all cars can be built using composite materials. Additive manufacturing, which presents a high but more constrained cost compared to traditional processes, was the object of this research. A framework was presented in [10] to analyze the viability of additive manufacturing in the automotive industry. The work in [11] presented an innovative lightweight design solution for a rear crash-management system for a C-class car. The two competing alternatives were described and compared in relation to design and technological solutions, including a sustainability analysis that assesses the entire life cycle (LC) of the system based on a wide range of environmental indicators. The materials currently available for additive manufacturing were not specifically developed for the automotive industry. For crash-relevant applications in particular, only a few alloys are available. Against this background, researchers [12] considered a novel aluminum alloy for automotive applications.