The Effect of Embedding Sensors on Composites Mechanical

The Effect of Embedding Sensors on Composite’s Mechanical Properties Arianna Verbosky, Mentor: Dr. Zegeye Abstract Conclusion Composite materials are materials that are made by dispersing fillers in a matrix. These materials have advantages such as a higher strength to weight ratio, ease of manufacturability, and corrosion and moisture resistance. Due to these advantages, their use in automotive, aerospace, sport goods, and defense sectors have increased recently. However, one of the concerns in using composite materials is the inability to continuously monitor the health of the materials during service. Current methods involve costly schedule maintenance. In the past, researchers have suggested the use of fully integrated monitoring systems such as state-ofthe art structural health monitoring (SHM) techniques as a promising solution. SHM systems involve integration of sensing elements in the composites to detect damage and failure during service. The method enables collection of large amounts of response data and analyze it to assess various health-related properties of structures in real-time. Carbon nanotubes (CNTs) and exfoliated graphite possess distinctive electrical properties that change when subjected to various strains and stresses. Several research studies suggest that these properties may make graphene derivatives and other such nanomaterials a potentially viable option for the creation of more precise strain sensors and gauges. These strain sensors can be embedded directly into composite materials, thus potentially enabling the performance of the composite to be measured during service. The embedded sensors are usually more conductive than the hosting composite and therefore it is possible to correlate the electrical signal change across these embedded sensors with the composite’s internal defects. Hence, the embedded sensors could provide meaningful information about the health of the composite material. However, due to the heterogeneity of the material composition, the embedded sensors may act as defects in the composite and could degrade its mechanical properties. The objective of this project is to determine the effects of embedding sensors in a composite’s mechanical property through fabricating sensor-embedded composite test samples and performing mechanical tests and measurements. A B Results This research aims to further investigate the effects of embedding strain sensors on the mechanical properties and behavior of the host composite. In seeking to provide a better understanding of how a material will behave when embedded with strain sensors, this research aims to contribute to the initiative to develop effective strain sensors that could be used in monitoring structural health of composite materials [2, 4]. To achieve this, the study involves the fabrication and mechanical testing of samples embedded with sensors created from exfoliated graphite to observe how the samples behave. The results from this study will aid in the search for how graphene derivatives and CNT strain sensors could be most effectively applied, manufactured, and utilized in various industries [1]. A A Figure 1: Fabrication of the Silicone Molds to create the Sensors Note: Verbosky A. , 2021. Silicone Mold Fabrication [Photograph] Future Work 1. Fabrication and testing of the sensors and samples 2. Investigating more effective and efficient methods to fabricate the sensor-embedded samples 3. Continue to test the sensor matrix design in other samples with the sensors created with different concentrations of the graphene nanoplatelets. § § 4. Determine the potential applications and implementation of sensor- and testing of the sensors and samples Investigating more effective and efficient methods to fabricate the sensor-embedded samples embedded composites Introduction 5. Work towards creating an effective method to fabricate sensorembedded composites using 3 -D printing and other additive Methods Research is conducted to study the nature of strain sensors made from exfoliated graphite. The sensors and samples are designed conceptually based on testing standards, and then virtual CAD models are created to visualize the necessary mold negatives to fabricate the sensors and the samples. The CAD models also serve as files to 3 D print the finalized mold negatives in ABS plastic. The mold negatives are used to make molds out of silicon rubber to be used in the fabrication of the sensors and samples. Once the molds are prepared, the exfoliated graphite composite sensors are created and then samples with and without the sensors embedded in them are fabricated. The fabricated samples are then subjected to mechanical tests to analyze and compare the effects of the embedded sensors in the hosting composite’s mechanical properties. manufacturing methods. Figure 2: Solid. Works Model of Mold Negative to Make Sensor Embedded Sample Note: Verbosky A. , 2021. Silicone Sample Mold [Digital] 1 2 Log 10 Optical Density at 600 nm Recently, researchers have become interested in the potential of nanomaterials such as Carbon Nanotubes (CNTs) and graphene derivatives to be used as embedded strain sensors in composite materials to monitor structural health more effectively and efficiently due to their unique electrical and material properties [1]. Both CNTs and graphene have distinctive electrical properties that change when they are subjected to strains and have the potential to be used as highly effective and precise strain sensors [1, 2]. Research has been recently conducted to determine the various properties of different forms of CNT’s and graphene being investigated to determine their strain-sensing abilities [3, 4]. However, there remains still many questions as to how a composite will behave when embedded with these strain sensors and what effect the embedded sensors will have on the composite’s mechanical properties. In this study, samples of composites with embedded sensors are fabricated and then tested to determine the effects of the embedded sensors on the its mechanical properties. 3 4 5 6 7 8 9 10 11 4 Figure 3: Solid. Works Model of Sensor Embedded Sample. Note: Verbosky A. , 2021. Sample Model [Digital] 12 4. 5 13 5 References 14 5. 5 6 6. 5 7 [1] G. T. Pham, Y. B. Park, Z. Liang, C. Zhang, B. Wang, Processing and modeling of conductive thermoplastic/carbon nanotube films for strain sensing, Comp. Part B 39(1) (2008) 209 -216. [2] J. Huang, S. -C. Her, X. Yang, M. Zhi, Synthesis and Characterization of Multi-Walled Carbon Nanotube/Graphene Nanoplatelet Hybrid Film for Flexible Strain Sensors, Nanomaterials (Basel) 8(10) (2018) 786. [3] A. Mehmood, N. M. Mubarak, M. Khalid, P. Jagadish, R. Walvekar, E. C. Abdullah, Graphene/PVA buckypaper for strain sensing application, Scientific Reports 10(1) (2020) 20106. [4] T. Yan, Z. Wang, Y. -Q. Wang, Z. -J. Pan, Carbon/graphene composite nanofiber yarns for highly sensitive strain sensors, Materials & Design 143 (2018) 214 -223.