Papers by Keyword: Composite

Abstract: 3D woven sandwich composites are being developed for transportation applications such as for light train flooring. For those applications, the joining process of these materials is needed. Mechanical joining is a common and preferable method for this purpose. In mechanical joints, it is critical to consider the pull-out resistance of the joint. This study investigated the pull-out resistance of a fiberglass-polyester 3D woven sandwich composite mechanical joint by adapting ASTM D7332 procedure B. The results indicate that increasing the hole depth and diameter enhances both the failure load and maximum load of the joints. Moreover, inserts significantly enhance failure load and maximum load (292% and 198% respectively) due to increased contact area, leading to improved mechanical joint performance. Specimens without inserts only showcased crack, crazing, and out-of-plane shear failure modes on composite while additional damage on insert and potting material was observed on with-insert specimens. The optimal mechanical joint configuration utilized an insert, featuring a hole depth matching the sandwich composite thickness (20 mm) and a hole diameter of 9 mm resulting in a failure load of 1690 N and a maximum load of 3042 N.

Abstract: An experimental study was performed to evaluate the effect of iron, ferronickel, and stainless steel 304L (85-92wt%) powder injection molding (PIM) on the compressive strength and rheological behavior of polyamide (PA6/M) composite. The feedstock, prepared at 260°C, was extruded into a composite film. The effect of particle shapes and size distribution was investigated using Scanning Electron Microscopy (SEM) to evaluate the relative viscosity value of the PA6/M feedstock. The results showed that the compressive strength and rheological behavior were determined by the blend composition. The increase in compressive strength was due to the higher strength of the metal powders compared to PA6, along with heightened surface energy leading to mechanical interlocking. Furthermore, the metal powders generated frictional resistance resulting in an increase in viscosity, making the feedstock unstable and decreasing the rheological properties. According to the compression and rheology test, all variations with an 85wt% metal powder exceeded the minimum specifications for frangible projectile materials. The highest compressive strength of PA6/85Fe was 144.503 MPa and the lowest viscosity of PA6/85FeNi was 352.85 Pa.s.

Abstract: Composite fibers are a significant aspect in changing the mechanical properties through the direction of the fiber. The proposed composite fiber organized by the direction of 90º-45º-90º, 45º-90º-45º, and 90º-90º-90º can add to the substitution of composite fiber that enhances stiffness and impact strength. Thus, the Acrylonitrile-butadiene-styrene ABS arrangement has a place with amorphous polymers that can expand the effect and increase the impact and the mechanical properties, for example, woven ramie utilizing different direction orientations. The outcomes show that the elasticity direction of 45º-90º-45º is 56wt%, 90º-45º-90º is 83wt%, and further increments while utilizing 90º-90º-90º is 94%. The analyses incorporate tensile tests to obtain tensile stress, tensile strain, and elastic modulus, which are performed on the ASTM D3039 utilizing the General Testing Machine Zwick Roell Z020. Findings demonstrated that specimens with various directions demonstrated mechanical characteristics that produce different mechanical properties through stress-strain analysis. The toughness of various directions can endure influence stacking without a fracture with 90º-45º-90º, and toughness for 45º-90º-45º and 90º-90º-90º show the stored energy without having permanent deformation ASTM D256 utilizing Zwick Roell Effect Analyzer HIT 2P. Furthermore, SEM images were also obtained to see the morphological changes on the composite polymer surface due to the tensile test. Overall, the utilization of the tensile test shows the maximum stress that the structure can maintain. Assuming fibers are oriented parallel to the main loading direction 0° and 90° will provide greater strength in that direction, while fibres diagonal 45º more absorb energy. By observing the SEM results, there is no reduction in strength and toughness through the 90º-45º-90º orientation of the layers using the hand laid-up technique.

Abstract: In this study, the elastic modulus of the 3D-printed Nylon filament reinforced with chopped carbon fiber as the matrix material and fiberglass (FG) as the reinforcement material, was evaluated using the Rule of Mixtures. Different configurations with various numbers of FG layers were added to the specimen, and all were subjected to tensile tests. The elastic modulus from the calculated values using ROM (Ε_c) and experimental results from the actual tensile test (E) of the 3D-printed composite material were compared. The results showed that the discrepancy between the Ε and Ε_c increases as the number of reinforcement layers also increases.

Abstract: Colorimetric intelligent food packaging requires an environmentally friendly biopolymer matrix with strong physical properties to retain anthocyanins as sensitive dyes effectively. This retention is crucial for enhancing the colorimetric response used in monitoring food freshness. The objective of this research is to investigate the physicochemical properties of intelligent food packaging films based on the mixing order of pectin and chitosan matrices, along with anthocyanins extracted from rambutan peels. Films were prepared from pectin (P), chitosan (C), pectin-chitosan (PC), pectin-anthocyanins (PA), chitosan-anthocyanins (CA), and various order of mixing film solution consists of pectin, chitosan, and anthocyanins, including pectin-chitosan-anthocyanins (PCA), pectin-anthocyanins-chitosan (PAC), and chitosan-anthocyanins-pectin (CAP). The results demonstrated that the CAP film exhibited favorable tensile strength (TS) of 2.3564 MPa and elongation at break (EAB) of 56.40%. Additionally, the CAP film retained a significant number of total anthocyanins after drying, with a content of 19.01 mg/100g, a total phenolic content (TPC) of 3439.63 mg/100g, and a radical scavenging activity (RSA) of 95.54%. Fourier transform infrared (FTIR) spectroscopy revealed spectral bands in the 3300-3600 cm⁻¹ and 1200-1250 cm⁻¹ regions, suggesting interactions or bonds between anthocyanins and either pectin or chitosan, possibly involving hydrogen bonding or modifications in C–O group structures. The color of the films changed across a pH range of 5–10, transitioning from pink to pale yellow and finally to greenish yellow. Based on these findings, the CAP film is identified as a promising candidate for colorimetric intelligent packaging applications.

Abstract: In this paper, a Ba_0.6Sr_0.4Fe_11.50Al_0.50O₁₉/MoS₂ composite with a weight ratio of 1:9 has been successfully created. The Ba_0.6Sr_0.4Fe_11.50Al_0.50O₁₉/MoS₂ was synthesized in HEM for 35 hours before sintered at 1000°C for 5 hours. The Ba_0.6Sr_0.4Fe_11.50Al_0.50O₁₉/MoS₂ composite was characterized using XRD for phase formation, crystal structure, and lattice parameters. Based on the XRD results, the Ba_0.6Sr_0.4Fe_11.50Al_0.50O₁₉/MoS₂ composite has two phases with different crystal structures. SEM characterization for surface morphology and particle size. SEM results show heterogeneous particles, but the particle size is not uniform at 0.2-0.6 µm. Measurements of the dielectric constant and dielectric loss are shown as a function of frequency. VSM is used to characterize samples magnetically. The VSM results show ferromagnetic behaviour in the Ba_0.6Sr_0.4Fe_11.50Al_0.50O₁₉/MoS₂ composite with the value of Mr, Ms, and Hc are about 20 emu/g, 40.769 emu/g, and 4.08 kOe, respectively.

Abstract: In the field of ballistic protection systems, Wire Arc Additive Manufacturing (WAAM) technology represents an innovative approach. WAAM offers a novel solution for producing complex components in ballistic protection systems. The process involves using an electric arc to melt metal wire, which is deposited layer by layer to form the desired structure. This method enables the creation of intricate geometries, presenting new possibilities for enhancing the ballistic resistance of protective systems. In this study, WAAM technology was employed to manufacture strike face layers for ballistic protection, with two types of welding wires selected to fabricate bimetallic composites. The produced components were evaluated in three configurations (COW, MCH, and Bim), which were subjected to ballistic testing with 7.62 mm FMJ M80 projectiles in accordance with the NATO AEP-55 STANAG 4569 standard. The results revealed that configuration II (MCH) exhibited complete ballistic resistance, meeting NATO AEP-55 STANAG 4569 level 1, while configuration III (Bim) demonstrated a higher velocity reduction compared to configuration I (COW).

Abstract: Waste materials (WAS) have recently been recycled into the environment and are materials that come to the fore in terms of both cost and environmental use. The waste material used in this study is a type of material classified as waste in a local textile factory due to the raising process, which cannot be converted back into textile. In this study, the effects of 5%, 10%, 15%, 20%, 25%, 30% and 40% waste raising on the mechanical and physical properties of the composite samples produced by combining them with epoxy were investigated. For comparison purposes, fabric reinforced samples made in previous studies were considered as reference samples. WAS 10 sample is the sample where the tensile strength value reaches its maximum. In the impact test results, the WAS 10 sample absorbed 1.63 times more energy than the WAS5 sample (1.3 J) that came after it, with 2.12 J. The WAS5 sample reached a hardness value of 205.067 in the microhardness test, 3.45% better than the WAS10 sample. Overall, it has been determined that the composite obtained from this waste material, which cannot be recycled into textile products, can be used as an alternative to interior plastics in the automotive industry.

Abstract: By using data from a conventional uniaxial test of the composite laminate in the design processes, safety factors might be overestimated which lead to unnecessary increase in size, cost and weight of the structure. Therefore, various bi-axial tests have been conducted in order to achieve the more realistic design. However, there is still a lack of reliable biaxial testing data to verify failure initiation and propagation of composite materials, due to the difficulties and expense of conducting these tests. In this study, a novel bi-axial testing fixture which can produce the tension – tension, tension – compression, compression – compression bi-axial loading conditions with different displacement ratios was developed with one loading actuator. This device is a cost-effective alternative for bi-directional material characterization tests which is utilized to validate of theoretical failure models.

Abstract: This research discusses synthesizing and characterizing magnetic hard-soft composite materials (Ba_0.6Sr_0.4Fe_11.5Al_0.5O₁₉/NiFe₂O₄) applied as microwave absorbers at S-band and C-band frequencies. The mechanical alloying method for sample synthesis uses a high-energy ball mill and sintering at high temperatures. Characterization of the crystal structure was done using an X-ray diffractometer. The Ba_0.6Sr_0.4Fe_11.5Al_0.5O₁₉ sample (hard magnetic) has a hexagonal structure, while the NiFe₂O₄ (soft magnetic) has a cubic structure. SEM analysis revealed a heterogeneous form with particle sizes ranging from 0.4 to 0.8 µm. Magnetization at room temperature was characterized using a vibrating-sample magnetometer (VSM). The magnetization saturation (Ms), magnetic remanent (Mr), and field coercivity (Hc) are 54.22 emu/g, 21.68 emu/g, and 0.876 kOe, respectively. Microwave absorption characterized using vector network analysis (VNA) shows that the hard-soft magnetic composite sample (Ba_0.6Sr_0.4Fe_11.5Al_0.5O₁₉/NiFe₂O₄) has a minimum reflection loss (RLmin) value of -29.86 dB for the S-band and -18.76 dB for the C-band area with an effective bandwidth reaching 2.34 GHz.