Development and characterization of an impact-resilient 3D nano-reinforced fiber metal laminate composite

全球汽车业最近面临的挑战是，到2025年将目前汽车的燃油效率提高近100%。最重要的策略之一是减轻车辆的重量，同时又保持所需的耐撞性。*为应对上述挑战，拟议的研究旨在开发一种混合复合材料，该材料(I)相对较轻，(Ii)提供所需的刚度和强度，(Iii)提供显著的耐撞性，(Iv)然而，它相对具有成本效益。这种新材料利用了轻质金属合金和相对便宜的玻璃钢的结合来应对这一挑战。换句话说，最近开发的真正新颖的3D玻璃纤维织物与轻质镁合金(MGA)薄板(比钢轻75%)相结合，形成了一种典型的纤维-金属层压复合材料(FML)。为了增强这种独特的复合板的性能，3D织物内的空洞可以填充轻质泡沫。*然而，在考虑将这种FML用于车辆之前，必须彻底了解其在关键载荷条件下的性能。在过去的三年里，我们一直在研究不同构型的3D-FML在面外冲击载荷下的性能。我们对FML在面内脉冲载荷作用下的性能的研究最近才开始。我们的初步研究表明，MGA与FRP界面粘结的质量对FML的屈曲和后屈曲响应有显著影响。因此，为了最大限度地发挥上述FML的性能，将使用最优化功能化的廉价纳米碳颗粒(即石墨烯小片)来经济和有效地增强界面的弹性。*此外，在未来的应用中促进开发的3D-FML使用的一个关键因素是能够预测FML在关键加载条件(例如轴向冲击)下的性能，并生成实用的设计曲线，这将使实践工程师能够针对给定的应用实现不同配置的3D-FML。这些任务必须分两个阶段完成。在第一阶段，对影响FML响应的各个方面进行数值表征。为了优化MGA/FRP接口的性能，我们将进一步提高我们小组过去三年开发的数值框架的预测能力，其中包括有效地使用内聚区模拟(CZM)。为此，我们打算使用最近发展起来的“扩展有限元方法”(Xfem)。因此，这部分研究的基本目的是获得使用XFE的经验，并研究GNP在用于匹配FRP和MGA板材的树脂中的影响，并优化粘接强度。**

The global automotive industry has been recently challenged to increase the current fuel efficiency of automobiles by nearly 100% by 2025. One of the most important strategies has been to reduce the weight of vehicles, yet adhering tp the required crashworthiness.******In response to the above challenge, the proposed research aims at developing a hybrid composite material that is (i) relatively light-weight, (ii) provides the required stiffness and strength (iii) offers remarkable crashworthiness and (iv) yet, it is relatively cost-effective. The new material takes advantages of the marriage of a light-weight metallic alloy and a relatively inexpensive FRP to address the challenge. In other words, a recently developed truly novel 3D glass fabric is combined with light-weight magnesium alloy (MgA) sheets (75% lighter than steel) to produce an exemplary fiber-metal laminate composite (FML). To augment the performance of this unique composite panel, the cavities within the 3D-fabric could be filled with a light-weight foam. ***However, before this FML can be considered in vehicles, one must gain a thorough understanding of its performance under critical loading conditions. In past three years, we have been investigating the performance of various configurations of the 3D-FML under out-of-plane impact loading. Our investigation on performance of the FML under in-plane impulse loading has begun very recently. Our preliminary investigation has revealed that the quality of the interface bond between MgA and FRP has a significant effect on the buckling and post-buckling response of the FML. Therefore, to maximize the performance of the said FML, optimally functionalized inexpensive nanocarbon particles (namely, graphene platelets), will be used to economically and effectively enhance the resiliency of the interfaces.***Moreover, a key factor in promoting the use of the developed 3D-FML in future applications is the ability to predict the performance of the FML under critical loading conditions (e.g., axial impact), and generation of practical design curves, which will enable practicing engineers to implement differently configured 3D-FMLs for a given application. These tasks would have to be done in two stages. In the first stage, various aspects affecting the response of the FML should be characterized numerically. To optimize the performance of MgA/FRP interface, we will further improve the predictive capability of the numerical framework developed in past three years within our group, which included the effective use of the cohesive zone modeling (CZM). For that we intend to use the relatively recently developed “extended finite element method” (XFEM). Therefore, the basic aim of this part of the proposed research is to gain experience with XFEM, and investigate the effects of GNP inclusion in the resin used to mate FRP to MgA sheets, and to optimize the bond strength. **