MRI: Acquisition of Low Velocity Impact Tester for Advanced Materials Research and Education

这项重大研究仪器（MRI）奖支持塔斯基吉大学（TU）收购最先进的落塔冲击测试仪。该仪器将使来自合成和生物基材料的更强和耐用的复合材料的开发成为可能。特别是，该仪器将改善TU的研究支持基础设施，用于研究低速冲击下的复合材料。这些低冲击速度是复合材料领域的主要关注点，因为由此产生的损坏通常未被检测到，并可能导致灾难性的故障。预计该仪器所实现的基础研究将推动复合材料在汽车，航空航天，民用，国防和其他工业应用中的使用。该仪器将由TU的教师和学生以及合作伙伴使用，从而鼓励协同研究合作。此外，课程相关的项目和实验的集合将提供给本科生和研究生。此外，这一工具将发挥关键作用，为TU继续产生一个有才华的和合格的非洲裔美国STEM毕业生池。低速冲击（LVI）下结构的失效机理是复杂的，因为结构经历了一系列的失效模式：由厚度方向剪切应力引起的基体开裂、由层合板弯曲产生的模式II层间剪切应力引起的分层以及由拉伸弯曲应力产生的纤维断裂。此外，FRPC暴露于恶劣的环境条件将进一步不利地影响LVI特性。因此，为了在设计寿命内安全运行，纤维增强复合材料（FRPC）在常规和恶劣条件下的LVI表征是极其关键的。最先进的Instron CEAST-9450落塔冲击试验机配备了一个恒温箱，适用于在高温和低温下测试FRPC。将使用冲击试验机进行的具体研究包括：黄麻和碳/黄麻混合纳米复合材料的破坏行为;受螳螂虾启发的仿生螺旋复合材料结构的冲击性能;混合复合材料在疲劳、冲击和弹道载荷下的结构分析;用于飞机的高温双马来酰亚胺基碳复合材料的耐久性;以及厚复合材料节点的设计、制造、测试和分析。该设备将作为发展FRPC科学和技术的优秀工具，同时提高塔斯基吉大学的研究和教育能力。该奖项反映了NSF的法定使命，并被认为值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估来支持。

This Major Research Instrumentation (MRI) award supports the acquisition of a state-of-the-art Drop Tower Impact Tester at Tuskegee University (TU). This instrument will enable the development of stronger and durable composite materials derived from synthetic and bio-based materials. Particularly, the instrument will improve TU's research support infrastructure for investigating composite materials under low velocity impact. These low impact speeds are a major concern in the composites field because the resulting damage often goes undetected and can lead to catastrophic failure. It is also anticipated that the fundamental research studies enabled by this instrument will result in advancing the use of composite materials in automotive, aerospace, civil, defense, and other industrial applications. The instrument will be used by faculty and students at TU and collaborating partners, thereby encouraging synergistic research collaborations. In addition, a collection of course related projects and experiments will be made available to undergraduate and graduate students. Moreover, this instrument will play a critical role for TU to continue to produce a talented and well-qualified pool of African American STEM graduates. The failure mechanism under low velocity impact (LVI) is complex as the structure undergoes a series of failure modes: matrix cracking due to through thickness shear stresses, delamination due to mode II interlaminar shear stresses generated by the bending of laminate, and fiber fracture generated by the tensile bending stresses. In addition, the exposure of FRPCs to harsh environmental conditions will further adversely affect the LVI properties. Therefore, for the safe operation over the designed lifetime, LVI characterization of fiber reinforced composites (FRPCs) in regular and harsh conditions is extremely critical. An automated state-of-the-art Instron CEAST-9450 Drop Tower Impact Tester equipped with a thermostatic chamber is suited for testing FRPCs at elevated and cold temperatures. The specific studies that will be carried out using the impact tester include: damage behavior of jute and carbon/jute hybrid nanocomposites; impact performance of biomimetic helicoidal composite structures inspired by mantis shrimp; structural analysis of hybrid composites under fatigue, impact and ballistic loadings; durability of high temperature bismaleimide based carbon composites for aircraft applications; and design, fabrication, testing and analysis of thick composite joints. This equipment will serve as an excellent tool in developing the science and technology of FRPCs, while enhancing the research and education capabilities at Tuskegee University.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.