Session: 02-01-06: 7th Annual Conference-Wide Symposium on Additive Manufacturing: Unique Applications II

Paper Number: 94366

94366 - Additive Manufacturing of Embedded Strain Sensors in Structural Composites 

Recent advances in additive manufacturing have transformed the manufacturing of polymers and composites, enabling the production of highly customized parts and components with enhanced mechanical, electrical, and thermal properties. Additionally, nanoparticles can be integrated into the polymer matrix and embedded into composites for beneficial functionalities including sensing, actuating, and control. Almost all commercially available additive manufacturing methods can benefit from the reinforcement of nanoparticles and structural fibers. Recent developments of additive manufacturing methods, such as fused deposition modeling, stereolithography, material extrusion, selective laser sintering, and laminated object manufacturing can be modified for the integration of nanoparticles and structural fibers. Additionally, strain gages made by carbon-based nanocomposites have been a particular research topic in the field of sensors. It is an important addition to the embedded sensor area as it consists of many advantages, such as great flexibility, ease of production, ability to read tiny changes in resistance, etc. It has great potential for applications in automobile, aerospace, and other high-tech industries due to its ability to detect deformation in the material.  The real-time monitoring of the load and deformation carried by the structures can lead to multiple benefits and open potential capabilities for advanced control, estimation of remaining useful life, improved structural integrity and enhanced safety.

In this research, a multi-walled nanotube-based nanocomposite is developed for the 3D printing of embedded strain sensors in structural composites. The formulation of nanocomposites is investigated, and the optimal nanotube concentration is identified, considering multiple aspects including cost, processing capability, and printing capability. The developed nanocomposites are directly printed onto glass fiber fabrics using the material extrusion-based additive manufacturing method. Then, the 3D printed nanocomposites in the format of strain gauges are employed for the fabrication of continuous fiber-reinforced composites with embedded sensors. To demonstrate the load and strain sensing capability, composite laminate beam samples are fabricated for testing. The microstructures, potentially embedded voids, and nanoparticle distributions are characterized using a scanning electron microscope. Moreover, the load sensing functionality of the manufactured glass fiber composites using embedded nanocomposite strain gauge is characterized under 3-point bending load conditions. The sensitivity, repeatability, and reliability of the 3D printed nanocomposites are experimentally characterized using a standard mechanical testing system. Particularly, the effects of maximum load and load rates on sensitivities of the developed composites are tested. The 3D printed strain gauges can be used for the monitoring of composite integrity, indicating their safety and reliability under complex and fatigue loading conditions.  

Presenting Author: Yingtao Liu University of Oklahoma

Presenting Author Biography: Dr. Yingtao Liu is an associate professor in the School of Aerospace and Mechanical Engineering at the University of Oklahoma.

Authors:

Dongfang Zhao University of Oklahoma
Jacob Meves University of Oklahoma
Anirban Mondal University of Oklahoma
Mrinal Saha University of Oklahoma
Yingtao Liu University of Oklahoma