2019 Poster Session Finalists

Highly porous and electrically conductive three-dimensional carbon nanostructure (3D CNS) was manufactured and its electrochemical performance was further enhanced by coating of polydopamine (PDA). Because PDA can provide an additional graphitic structure, a nitrogen-doping effect, and a hydrophilic effect with unshrinkable structure, the PDA-coated 3D CNS can have superior specific capacitance and energy density. In this work, the PDA-coated 3D CNS was used as structural supercapacitor electrodes by coating on the surface of carbon fiber plain-woven fabrics. As a mechanically robust electrolyte, aramid nanofibers (ANF) were uniformly dispersed into epoxy resin, and the ANF-reinforced epoxy was mixed with ionic liquid (LiTFSI/BMIM-TFSI). Therefore, the severe degradation of epoxy resin by introducing liquid electrolyte, can be successfully minimized by using highly stiff ANFs. Finally, we fabricated multi-layer carbon fiber composites can perform bi-functional roles as a structural load-bearer and an energy storable supercpacitor.

Submitted by Prof. Wonoh Lee, Chonnam National University

The regenerative cooling technology of the supersonic combustor not only cools the heated wall surface by using the fuel, but also promotes the combustion by the preheating of the fuel at the same time. Conventional metal based high-temperature materials have greatly deteriorated mechanical properties at temperatures over 1000K, making them incapable of long-term use and reuse in combustor parts of scramjet engines. In this study, structural analysis and pressure tests were carried out to apply carbon fiber reinforced ceramic composites to regenerative cooled combustors of scramjet engines exposed to high temperature environments over 2000K. The purpose of this study is to apply carbon fiber reinforced silicon carbide ceramic composite (C/SiC) with heat resistance temperature of 1600K to the top and bottom panels of regenerative cooled combustor end exposed to the hottest environment among supersonic combustor systems. A finite element analysis was carried out to verify the structural safety of the composite combustor panel with the internal flow path and the pressure test was carried out using a hydraulic test equipment.

Submitted by Soo-Hyun Kim, Korea Institute of Energy Research

In recent years Shape memory polymers (SMPs) and composites have been under intense investigation due to their ability to change size and shape upon exposure to an external stimulus (e.g. light, heat, pH, or magnetic field). These materials are used for bio applications, however recent attempts have been under broad investigation due to their unique mechanical, thermal, and electrical properties for use in aircraft and space applications. In this work, thermally responsive epoxy based SMPs and nanocomposites were developed and the shape memory behavior and thermo-mechanical properties were studied.

Submitted by Dr. Duyoung Choi, Korea Institute of Industrial Technology

Two-way (reversible) chemically crosslinked semi-crystalline shape memory polymers with various crosslinking densities were synthesized by poly(ethylene-co-vinyl acetate) (PEVA) with different contents of benzoyl peroxide (BPO). The developed materials exhibited reversible shape changes by controlling the switch on temperature that triggers shape change within a reasonable temperature range. The PEVA-B10 samples exhibited both optimal actuation performances and excellent recovery ratio over 99%. BPO as the crosslinker played an important role in allowing samples to return to their original shape, and the developed samples (PEVA/BPO soft materials) with high crosslinking density led to a significant increase in recovery ratio. As a result, the developed PEVA/BPO materials indicated enough soft performance and good mechanical properties even at large deformation, which may contribute to the potential applications in the fields of soft material actuators and other applications.

Submitted by Jin Hui, Interdisciplinary Graduate School of Science and Technology, Shinshu University

Objective: To design and Manufacture a small Electric aircraft to transport lightweight to medium size cargo to short distances preferably under 500 miles. This will be a two seate aircraft with cargo space up to 8 ft by 4 ft wide and measuring no more than 30 ft in length. The aircraft will be designed with the use of Solid-works. The Solid-works CAD program will allow me to design aircraft parts, select materials, and assemble the entire aircraft. The aircraft will also be able to be designed for continuous improvement which will include; Changes of material, color, rendering, and etc. Purpose: The purpose of this aircraft is to be Environmental friendly and provide lower operation and maintenance cost. It will also prevent airports from utilizing large piston or Jet powered aircraft for delivering small amount of cargo to short range travel. It will be designed to deliver cargo to short-range distances preferably under 500 miles and carry less than 500 pounds of cargo approaching speed of up to 200 Miles per hour. Another purpose of this aircraft is to make the manufacturing of small and medium aircraft simpler. New technologies will be utilized to manufacture airplanes including Laser, Water-jet and Plasma cutter to manufacture aircraft and parts, selecting materials including lightweight aluminum and composite material, Utilizing Solid-works and Auto-desk for design and Continuous upgrade for future aircraft design. Certain parts of the aircraft will also be eligible for additive manufacturing which includes the Winglets, wing rudders, and other small components. Conclusion: I would like this aircraft to serve with major shipping companies including UPS, Fed Ex, Amazon and other major airlines and shipping coporations. The aircraft can also be used for private business uses. The aircraft will also be eligible for continuous improvement. Improvement includes upgrades in design and materials, increase in speed and range, improvements in cargo carrying capabilities, speed performance and also a change in Engine and electronics.

Submitted by Jerry Weems, Sheetmetal Manufacturing Engineer

Due to their exceptional mechanical and physical properties, carbon nanotubes (CNTs) have been widely used in fabricating multiscale composites. In this work, CNTs were deposited onto glass fibers using a novel scalable electrophoretic deposition method. The CNTs are functionalized with dendritic polyelectrolyte plolyethyleneimine (PEI) and sonicated in an aqueous solution. This solution is adjusted to a pH of 6 using glacial-acetic acid in order to functionalize the amine groups and form a stable dispersion of positively charged carbon nanotubes, which are then deposited on unidirectional glass fibers. Four plies of CNT coated glass fibers are used to make cross-ply [0/90]s specimens. These specimens were tested under tension while monitoring resistance. Due to the transverse cracks in the 90 plies, the conductive network was disrupted, increasing the resistance. The sensing capabilities of CNTs was validated using edge replication and acoustic emissions sensors. The resistance response correlates with the measured crack density and acoustic emission hits. The initiation and growth of transverse cracks is able to monitored without significantly compromising the mechanical properties of the glass fiber composites.

Submitted by Colleen Murray, University of Delaware

Utility (Fire fighting) Helicopter Purpose Medium size Utility Helicopter made of composite materials and metallic structure for firefighting, search and rescue, Military support missions, and operating in disaster prone areas. This helicopter will carry a crew of six including a pilot and copilot and the Helicopter will feature composite structure, Insulation materials for fireproof and crew protection, Utility Pods and nose mounted water hose for fighting fires. Design Process: The helicopter will be designed with the use of Solid-works. With this program I will design the Structural parts, Interior, the Engine cover, tail boom, and the outer composite materials. This will involve material selection, selection of texture and color, and possibilities of continuous improvement in design and manufacturing. Material type. The interior structure will be made of high grade Aluminum or light weight steel. The Aluminum or steel frame will be processed either through Plasma or Waterjet cutting and the structure will be supported by metal beams.
The helicopter will stress the use of fire resistance materials. The side panels will feature materials including Aluminum, rubber for insulation, Composite exterior cover, and fire resistant paint. The engine cover will stress the use of Composites material including rubber and metal infused together, Graphite fibers or Kevlar for exterior covering which has greater stiffness and higher strength fibers to tolerate high temperature environments, protection of engine vibration and other outside elements. The Helicopter will also utilize corrosion resistance paint for operating in extreme heat and other bad weather conditions. Other composite structures will include Aluminum sandwich panel flooring which is also fire resistant, additive manufactured seats, and additive manufactured parts including the tail wing and tail rotor. The outer Utility pods will most likely be made of Composite material for water and fire retardant storage. The Utility pods will also have fire resistant qualities, the outer exterior will be made of a Graphite material and be covered with fire retardant paint. Benefits: Capable of extinguishing fires at a closer range and rescuing civilians and crew members while advanced composites protect Helicopter pilot, passengers and equipment from extreme heat and dangerous elements whether man made or natural disasters. Helicopter will be capable of carrying wing mounted composite built Utility Pods for carrying extra water, fire retardants, and personal utilities for firefighting and search and rescue applications.

Submitted by Jerry Weems, Sheetmetal Manufacturing Engineer

New low thermal expansion (LTE) casting alloys with high yield strength have been developed as molding die materials for carbon fiber reinforced plastic (CFRP). Molding dies of CFRP in aerospace industries are often made of LTE alloys either rolled or cast. Fe-36%Ni LTE alloy is used for autoclave process and Fe-29%Ni-17%Co LTE alloy for hot press process [1]. Casting alloys are cost-effective, but have problems of low yield strength and Young’s modulus because their grain sizes are coarse in comparison with rolled or forged alloys [2]. The new alloys have been developed by using an advanced process of cryogenic treatment for martensitic transformation combined with after-annealing for recrystallization and reversible transformation. 36%Ni alloy do not transform to martensite at liquid nitrogen temperature of 77 K. The composition was modulated to 34%Ni in order that martensitic transformation occurred at 77K. 29%Ni-17%Co LTE Alloy has larger coefficient of thermal expansion (CTE) than CFRP, and then the content of Ni and Co was adjusted to 30%Ni-15%Co to have equivalent CTE to CFRP. The recrystallization and reversible transformation after martensitic transformation refined grains of the alloys. Their yield strength increased by 70 to 180% from the original casting alloys. The alloy was adopted for volume-production of guide vanes and the benefits were confirmed.

Submitted by Shin Utsunomiya, National Astronomical Observatory of Japan

Internal strains originating during processing of carbon fiber reinforced polymer composites are associated with volumetric shrinkage of glassy polymer matrix networks upon curing. Benzoxazine based networks have been proven to exhibit low cure induced shrinkage upon polymerization becoming a good candidate for manufacturing polymer composites with low internal strains. The benzoxazine system chosen for this research consists of a difunctional Bisphenol-A/aniline based benzoxazine monomer. The monomer synthesis is carried out in a twin screw extruder which can make possible a large scale continuous production of this system. Different cure protocols are performed and studied through Differential Scanning Calorimetry (DSC) to understand extent of conversion of the network at different curing times. In this research, several techniques to measure the volumetric tendency upon polymerization of benzoxazine networks are presented. Density measurements, Pressure-Volume-Temperature dilatometry (PVT), and Thermomechanical Analysis (TMA) are performed and the results from each technique are compared. For these measurements, the critical gelation point of the Bisphenol A based benzoxazine is taken as the starting point of the test and the volumetric evolution of the sample upon cured is studied. The critical point of gelation of this system is determined by a multifrequency rhelogical study. Outcomes of this research provide new knowledge in a highly desired area of composite materials science, which quantifies the effects of low-volumetric shrinkage glassy polymer networks upon cure and their reduction of internal strains for fiber reinforced polymer matrix composite materials.

Submitted by Bernardo Barea Lopez, University of Southern Mississippi

Graphene is of great interest for its excellent thermal, electrical, and mechanical properties at low loading levels. However, to realize the maximum potential benefits in these areas of interest, the graphene nanoplatelets must be adequately dispersed. When working in thermosets, the dispersion must be controlled throughout the entirety of cure. Even with initially well dispersed nanoparticles, the early stages of network formation when viscosity is lowest often results in the formation of large agglomerates, which cause stress concentrators in the cured network, ultimately reducing performance and sacrificing desired properties. In this work, graphene nanoplatelets (GNPs), which are graphitic structures ten- to twenty-layers thick that offer micrometer length and width but nanometer thickness dimensions, are dispersed using a high shear continuous reactor into high Tg epoxy matrices. The cure prescription is altered to control viscosity, and ultimately, GNP dispersion state throughout cure. The dispersion is analyzed through cure using optical microscopy (OM) and correlated with the rheokinetics of cure to determine a critical viscosity of GNPs that limit reagglomeration. Exfoliation of GNP is examined using wide angle X-ray scattering (WAXS) to monitor D-spacing and small angle X-ray scattering (SAXS) is used to determine tactoid thickness of the platelets. Thermomechanical and thermal analysis will be evaluated using thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA) to characterize all nanocomposites. The control of dispersion throughout the entirety of cure offers the potential for significant matrix improvement, but only when dispersion throughout the entirety of cure is controlled.

Submitted by Matthew Hartline, University of Southern Mississippi

The processes of extracting carbon fibers from expired prepreg and end-of-life composites are still within the early stages of development. However, there is substantial evidence that chemistry-based recycling techniques can extract a matrix completely from the reinforcement and obtain fibers that maintain properties comparable to virgin fibers. Although there is an abundance of literature assessing the impact of chemistry recycling techniques on carbon fiber, little research has been published on the impact that these recycling processes have on the matrix material that is separated from the carbon fiber reinforced plastics (CFRPs). The purpose of this research was to examine the impacts of chemistry-based recycling on b-staged epoxy matrices obtained from prepreg sourced from manufacturing scrap. This work aimed to fully characterize the thermal, rheological, mechanical, and surface properties of the recycled, b-staged epoxy matrix. Heat-cool-heat differential scanning calorimetry (DSC) was conducted to establish the recycled resins glass transition temperature (Tg) after recycling and its ultimate Tg after full cure. Rheological characterization was performed to determine the epoxy’s gel point, minimum viscosity and pot-life at a variety of elevated temperatures. Tensile bars were prepared and tested following ASTM D3039 to understand the effects of recycling on mechanical properties. Dynamic mechanical analysis (DMA) experiments were conducted to confirm the materials ultimate glass transition temperature and observe the recycled resins crosslink density as the temperature was elevated. Finally, the total surface energy of the recycled matrix obtained using the Fowkes Theory.

Submitted by Dr. John Misasi, PhD, Western Washington University

Lightweight energy absorption system for vehicle front end is a unique design. It is an Effective Solution towards Efficient Energy Management & Light weighting. A mixed material strategy in automotive is key to achieve in sustainability. The use of composite will allow us to lower overall vehicle mass which will help us improve our fuel economy as well as reduce the CO2 emissions. This innovative application of thermoset composite to replace the front steel beam to allow us to lower the overall mass of the beam as well as improve the overall energy management of front bumper beam.

Submitted by Praveen Kumar, Mahindra & Mahindra

Thermoset nanocomposites are of great interest to the composites industry due to their excellent thermal and mechanical properties, however they remain challenging to process using traditional composites manufacturing techniques due to the high minimum viscosities required to maintain nanomaterial dispersion during cure. Direct ink writing (DIW) is an additive manufacturing technique in which a high viscosity feedstock is extruded through a micro-nozzle in a layer-by-layer fashion to form a 3 dimensional part. This work investigated the viability of manufacturing benzoxazine-based nanocomposites using DIW. Benzoxazine was blended with carbon nanostructures and polycarbonate to produce a direct ink writing feedstock. The blends were characterized using parallel-plate rheology and differential scanning calorimetry (DSC) to analyze the viscosity and the cure characteristics of the blends. Thermogravimetric analysis (TGA) was used to study thermal stability and char yield of the cured blends. Additive manufacturing was performed using a Hyrel System 30M. Tensile strength was characterized through tensile testing using ASTM standard D3039, and glass transition temperature/degree of cure was identified using dynamic mechanical analysis (DMA). Scanning electron microscopy (SEM) was used to analyze the dispersion and agglomeration of the carbon nanostructures.

Submitted by Dr. John Misasi, PhD, Western Washington University

Laminated composite materials generally fail because of delamination that is due to poor interlaminar strength or out-of-plane strength, which is mainly associated with the lack of reinforcement in transverse or thickness direction. In addition, most composite assemblies and structures generally fail due to the poor performance of their bonded joints that are assembled together with an adhesive layer. Adhesive failure and cohesive failure are among the most commonly observed failure modes in composite bonded joint assemblies. These failure modes occur due to the lack of reinforcement within the adhesive layer in transverse direction. The overall performance of any composite assembly largely depends on the performance of its bonded joints. Based on our prior studies, nanoscale reinforcements (e.g., carbon based nanomaterials) could be used as a viable solution to address these problems. In the in the first part of this work, carbon nanotubes (CNTs) with straight and helical geometries were incorporated in epoxy resin and then they were used to fabricate laminated nanocomposites. To examine the effectiveness the carbon nanotube reinforcements, test specimens were prepared and then tested for flexural properties, based on the ASTM standard D790. The test results showed that the presence of carbon nanotubes within the resin system and in between the fiber filaments and fabrics can considerably improve the flexural strength and modulus of the laminated nanocomposites. In the second part of this work, helical carbon nanotubes (HCNTs) were incorporated into an adhesive resin in various weight percentages for bonding of composites. The goal was to improve the properties of the adhesive film and their interfacial bonding effectiveness. Single lap joint test specimens were prepared based the ASTM Standard D5868-01 and then tested to investigate the effectiveness of the HCNTs for improvement of the composite bonded joint assemblies. The results showed that the presence of HCNTs in adhesive layers do play an important role for effective bonding of load carrying composite structures.

Submitted by Dr. Davood Askari, Wichita State University