Browse Topic: Carbon fibers
This SAE Aerospace Recommended Practice (ARP) provides methods and guidelines for isolating dissimilar repair patch materials from carbon fiber reinforced plastic (herein also referred to as carbon composite) structure during a repair operation.
Fused deposition modeling (FDM) is a rapidly growing additive manufacturing method employed for printing fiber-reinforced polymer composites. Nonetheless, the performance of printed parts is often constrained by inherent defects. This study investigates how the varying annealing parameter affects the tribological properties of FDM-produced polypropylene carbon fiber composites. The composite pin specimens were created in a standard size of 35 mm height and 12 mm diameter, based on the specifications of the tribometer pin holder. The impact of high-temperature annealing process parameters are explored, specifically annealing temperature and duration, while maintaining a fixed cooling rate. Two set of printed samples were taken for post-annealing at temperature of 85°C for 60 and 90 min, respectively. The tribological properties were evaluated using a dry pin-on-disc setup and examined both pre- (as-built) and post-annealing at temperature of 85°C for 60 and 90 min printed samples
Carbon-fiber structural batteries are not entirely new, but now Sinonus, a company spun out of Chalmers Technical University in Gothenburg, Sweden, is further developing the technology with carbon fibers that double as battery electrodes. The technology has already been demonstrated in low-power applications, and Sinonus will now develop it for use in a range of larger applications including, first, IoT devices and then drones, computers, electric vehicles and airplanes. By integrating the battery into carbon-fiber structures, Sinonus believes that an EV's weight could be reduced while the driving range could increase by as much as 70%. The carbon-fiber technology used by Sinonus originated at Oxeon, another Chalmers spin-off.
Composite materials play an important role in aerospace manufacturing. The light weight, durability and ability to create complex shapes from molds make these materials ideal for frames and structural components that enable lighter, more fuel-efficient aircraft. While composite structures can weigh up to 20 percent less than their metal counterparts, these materials can often be more difficult to machine. The extremely abrasive nature of carbon fiber reinforced polymers (CFRPs) will wear down standard cutting tools more quickly than almost any other material. A standard carbide cutting tool may only hold up to cutting a few feet of CFRPs before its dimensional stability fails, while in traditional metal machining that same tool might last 20 to 50 times that before wearing out.
Recycling of advanced composites made from carbon fibers in epoxy resins is required for two primary reasons. First, the energy necessary to produce carbon fibers is very high and therefore reusing these fibers could greatly reduce the lifecycle energy of components which use them. Second, if the material is allowed to break down in the environment, it will contribute to the growing presence of microplastics and other synthetic pollutants. Currently, recycling and safe methods of disposal typically do not aim for full circularity, but rather separate fibers for successive downcycling while combusting the matrix in a clean burning process. Breakdown of the matrix, without damaging the carbon fibers, can be achieved by pyrolysis, fluidized bed processes, or chemical solvolysis. The major challenge is to align fibers into unidirectional tows of real value in high-performance composites.
A team of inventors from NASA Langley and NASA Ames have created a new type of carbon fiber polymer composite that has a high thermal conductivity. This was achieved by incorporating Pyrolytic Graphite Sheets (PGSs) and Carbon Nanotubes (CNTs), which enhance the material’s ability to transfer heat when compared to typical carbon fiber composites.
This article explores the impact of As-built versus annealed Fused Deposition Modeling (FDM) on the mechanical properties of test samples fabricated from two distinct materials: Polyamide 6 (PA6) and PA6 with carbon fiber filament. Employing the FDM technique, these samples were meticulously produced, with significant process parameters maintained at optimal values. Two sets of printed specimens were prepared for examination, one composed of PA6 and the other of PA6 with carbon fiber (CF) reinforcement. The first set was subjected to mechanical testing in its As-built condition, while the second set underwent an annealing process utilizing a muffle furnace. The annealing reduces internal stresses, enhances interlayer adhesion, and promotes crystallinity. For both the sent samples exposed to comprehensive assessments to evaluate various mechanical performance attributes, including hardness, impact strength, tensile strength and flexural strength. The results of this study elucidate that
Additive manufacturing (AM) is a common way to make things faster in manufacturing era today. A mix of polypropylene (PP) and carbon fiber (CF) blended filament is strong and bonded well. Fused deposition modeling (FDM) is a common way to make things. For this research, made the test samples using a mix of PP and CF filament through FDM printer by varying infill speed of 40 meters per sec 50 meters per sec and 60 meters per sec in sequence. The tested these samples on a tribometer testing machine that slides them against a surface with different forces (from 5 to 20 N) and speeds (from 1 to 4 meters per sec). The findings of the study revealed a consistent linear increase in both wear rate and coefficient of friction across every sample analyzed. Nevertheless, noteworthy variations emerged when evaluating the samples subjected to the 40m/s infill speed test. Specifically, these particular samples exhibited notably lower wear rates and coefficients of friction compared to the remaining
The evolution of materials technology has provided in recent decades the replacement of the raw material of many parts made of metal by polymers, carbon fibers, ceramics, and composite materials. This process has been driven by the permanent need to reduce weight and costs, which, even after replacing raw materials, still demand permanent improvement and optimization in the sizing process and in the manufacturing process. In the automotive industry, many components have been replaced by fiber-reinforced polymers, from finishing parts to structural components that are highly mechanically stressed and often also subjected to high temperatures. Although they are lighter and have a lower final cost than conventional metallic parts, components made of fiber-reinforced polymers bring great technological challenges to the development project. Within this context, computational modeling is an indispensable ally for obtaining a product capable of meeting the severe conditions required for its
The U.S. Army fields a multitude of aircraft mission design series (MDS) developed by several different original equipment manufacturers with varying mission requirements and flight profiles. The structural analysis in this work assumes the materials, tooling, skillsets, and capabilities are organically available and proper at the repair location. Army Combat Capabilities Development Command, Redstone Arsenal, Alabama The U.S. Army operates and maintains several aircraft MDS to meet the warfighter's multidomain mission. Aircraft fielded by the U.S. Army originate from multiple equipment manufacturers. These aircraft include rotary-wing configurations such as the AH-64D/E Apache, CH-47F Chinook, and H-60A/L/V/M Blackhawk aircraft which significantly vary in mission parameters and flight profiles. These aircraft contain structures made from a majority aluminum, steel, and titanium alloys which have dominated aircraft designs for much of the history of powered flight. However, the use of
Innovators at NASA Johnson Space Center have developed a carbon fiber reinforced polymer (CFRP) sleeve, that, when fitted over a cylindrical Li-ion battery cell, can prevent cell-to-cell propagation by containing a thermal runaway (TR) event to the originating cell.
Discontinuous or short-fiber composites are traditionally less expensive and are normally less difficult to manufacture than continuous fiber composites, while still retaining some of the benefits of reinforcing fibers. Similarly to continuous fibers, the volume ratio influences the mechanical properties of the composite. In addition the ratio of the length and diameter of the reinforcing fibers also plays a significant role. This ratio (also known as the aspect ratio) adds another variable to the anisotropic properties of lamina plies where now not only the content of fibers but also the dimensions of the fibers themselves play a role. Short fiber reinforced composites are already used in additive manufacturing techniques; however, the amount of carbon fiber and the length of the discontinuous strands in the filaments are normally not stated or vary greatly. An investigation in conducted on how the dimensional properties of the carbon fiber, (volume fraction and aspect ratio), affect
In this research, the aim is to investigate the tensile properties and microstructures of Aluminium 6061 hybrid composite before and after extrusion. Aluminium 6061 Hybrid composite was fabricated using Stir casting technique with 6 Weight % silicon nitride (Si3N4) coated with nickel and 1Weight % carbon fiber (Cf) coated with copper as reinforcements followed by extrusion process. The tensile properties and microstructures of extruded hybrid composite was investigated and compared with as-cast hybrid composite. The microstructure of the hybrid composite showed excellent bonding between matrix and reinforcements interface. The hot extruded hybrid composite exhibited enhanced yield strength (44%), ultimate tensile strength (33%) and % elongation (20%) when compared with as-cast hybrid composite. Scanning electron microscopy (SEM) and Energy dispersive spectroscopy (EDS) techniques were used to observe the fracture surfaces of tensile testing specimens.
In the era of rapidly increasing of EV/AVs, there are more electronic Modules/sensors & bigger battery packs added to EV (Electric Vehicles) vehicles, which has resulted in added mass penalty thereby impacting the range of EV vehicles. Range anxiety remains one of the biggest obstacles to widespread electric-car adoption, which drives the necessity of mass optimization to improve EV range. Multi-material design is a trend to lightweight automotive structures. The automotive industry is looking to make use of carbon fibers in their subsystem design. The challenge in current unidirectional carbon fiber design is difficulty to tailor stiffness/ strength across the fiber direction & orienting plies to system / vehicle load path. Optimization of ply angle for unidirectional composite provides constant fiber angle across the ply which does not address multiple load paths of all component /system. This drives for an opportunity to get the fiber angles tailor made to specific load path
ABSTRACT This paper focuses on the application of a novel Additive Molding™ process in the design optimization of a combat vehicle driver’s seat structure. Additive Molding™ is a novel manufacturing process that combines three-dimensional design flexibility of additive manufacturing with a high-volume production rate compression molding process. By combining the lightweighting benefits of topology optimization with the high strength and stiffness of tailored continuous carbon fiber reinforcements, the result is an optimized structure that is lighter than both topology-optimized metal additive manufacturing and traditional composites manufacturing. In this work, a combat vehicle driver’s seatback structure was optimized to evaluate the weight savings when converting the design from a baseline aluminum seat structure to a carbon fiber / polycarbonate structure. The design was optimized to account for mobility loads and a 95-percentile male soldier, and the result was a reduction in
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