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

该主要研究仪器（MRI）奖支持在塔斯基吉大学（TU）获得最先进的落塔冲击测试仪。这一仪器将有助于开发从合成材料和生物基材料衍生的更坚固和耐用的复合材料。特别是，该仪器将改善TU在低速冲击下研究复合材料的研究支持基础设施。这种低冲击速度是复合材料领域的一个主要问题，因为由此产生的损伤通常无法被发现，并可能导致灾难性的故障。此外，预计该仪器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应用。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，还将为本科生和研究生提供一系列与课程相关的项目和实验。此外，这一工具将在TU继续培养有才华和合格的非裔美国STEM毕业生方面发挥关键作用。低速冲击（LVI）作用下的破坏机制较为复杂，结构经历了一系列破坏模式：通过厚度剪切应力导致基体开裂，层合板弯曲产生II型层间剪切应力导致分层，拉伸弯曲应力导致纤维断裂。此外，frpc暴露于恶劣的环境条件将进一步对LVI性能产生不利影响。因此，为了在设计使用寿命内安全运行，纤维增强复合材料（frpc）在常规和恶劣条件下的LVI表征至关重要。配备恒温室的自动化最先进的Instron cast -9450跌落塔冲击测试仪适用于在高温和低温下测试frpc。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损伤行为；螳螂虾仿生螺旋复合材料结构的冲击性能混杂复合材料在疲劳、冲击和弹道载荷下的结构分析飞机用高温双马来酰亚胺基碳复合材料的耐久性研究以及厚复合材料接头的设计、制造、试验与分析。该设备将成为发展frpc科学和技术的优秀工具，同时增强塔斯基吉大学的研究和教育能力。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

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.