Ultra-high Molecular Weight Polyethylene Research Articles

Dynamic Behavior of Twisted UHMWPE Yarns

Twisting is an effective method to reduce defects during fabric weaving and improve the impact resistance of the armor material. This study examined the dynamic behavior of twisted ultra-high molecular weight polyethylene (UHMWPE) yarns. Material characterization was conducted using three-dimensional X-ray tomography and scanning electron microscopy (SEM). Dynamic mechanical experiments were carried out on the twisted yarns using a Kolsky bar, with the yarn's failure process captured in real time through high-speed imaging. Additionally, the digital imaging correlation (DIC) technique was used to calibrate the strain measured by the Kolsky bar. Post-fracture analysis was performed using SEM. The effects of twisting extent, strain rate, and gauge length on the dynamic behavior of twisted yarns were studied. It was observed that all twisted yarns underwent elongation, shrinkage, fiber breakage, untwisting, and yarn rupture. Furthermore, as the twisting degree and strain rate increased, and the gauge length decreased, the fracture area became more concentrated. The tensile strength peaked at a twisting degree of 250 t/m and decreased thereafter. Moreover, twisting was found to alter the sensitivity of the yarns' stress–strain curves and tensile properties to the strain rate and gauge length.

Sliding mass floor system for seismic response control

A new concept of small sliding mass blocks as distributed bi-directional friction tuned mass dampers (TMD) is developed and tested for seismic response control of a framed building model. The proposed distributed TMD system can be accommodated within a depth of 10 cm at each floor of the building and does not require any specialized tools and is suitable for enhancing seismic performance of existing buildings as well. An analytical model has been developed for the modelling of distributed friction TMDs and the model has been validated by comparing predicted response with the experimental observations during a shake table test for a steel portal frame with distributed friction TMDs. It is found that the proposed distributed friction TMDs can reduce the seismic response by as much as 60% for mass ratio of 8% and tuning ratio of 0.9 with respect to the first normal mode of the building. A parametric study using different earthquake ground motions suggests that the coefficient friction of 0.2 has the most robust performance. The interface between ultra high molecular weight polyethylene (UHMWPE) and steel provides the desired coefficient of friction. This pair of sliding interfaces is also desirable from the point of view of durability as UHMWPE is highly abrasion resistant and is widely used in orthopedic implants. The proposed arrangement of distributed friction TMDs readily allows for the possibility of each mass block to be used as bi-directional TMD and tuned to different mode of vibration, if required. These distributed TMDs are also found to be very effective in greatly reducing the storey drifts in buildings on hill slopes. The results suggest that it is possible to achieve the immediate occupancy performance objectives even during extreme (MCE) level events with the help of proposed distributed friction TMDs.

Temperature and Strain Rate Related Deformation Behavior of UHMWPE Fiber-Reinforced Composites.

As they possess the qualities of high specific strength, high specific modulus, high specific energy absorption, and excellent designability, ultra-high molecular weight polyethylene (UHMWPE) fiber-reinforced composites have gradually replaced traditional materials such as ceramics and steel plates as the main ballistic protection materials. Using an improved test method, the uniaxial tensile tests of UHMWPE fiber-reinforced composites at two strain rates of 10-4 s-1 and 10-2 s-1 and a temperature range from -20 °C to 80 °C are carried out to study the effects of strain rate and temperature on the tensile behavior of UHMWPE fiber-reinforced composites. The experimental results indicate that the tensile responses exhibit nonlinear characteristics and the sensitivity of strain rate and temperature. The yield strength and modulus decrease with increasing temperature and increase with the increase in strain rate. A phenomenological viscoelastic constitutive model composed of a nonlinear spring and a nonlinear Maxwell element is proposed to characterize the temperature and strain rate dependent deformation behavior of UHMWPE fiber-reinforced composites before yielding. The results show that the model can accurately predict the tensile nonlinear viscoelastic responses of UHMWPE fiber-reinforced composites before yielding over a wide temperature range under quasi-static loading.

Characteristics of VE/HXLPE wear particle morphology: A comparative analysis with UHMWPE in an in vitro artificial tibial insert simulation test

Particle generation from artificial knee prostheses is a leading cause of artificial joint failures. Vitamin E stabilized highly cross-linked polyethylene (VE/HXLPE) is known for its antioxidant properties and minimal wear characteristics. However, research on the wear behavior of VE/HXLPE is limited. This study aims to compare wear debris from VE/HXLPE with the conventional material Ultra High Molecular Weight Polyethylene (UHMWPE) under identical in vitro test conditions. Specifically, Principal Component Analysis (PCA) was employed to morphologically categorize particles, resulting in four distinct groups for VE/HXLPE and five for UHMWPE. Notably, 68 % of VE/HXLPE particles exhibited small-sized spheroidal morphology, while UHMWPE mainly produced elongated bioactive particles. Key particle attributes were then assessed, including 'equivalent circle diameter (ECD)', 'aspect ratio (AR)', and 'roundness (R) ', and presented as frequency distributions. The morphological analysis revealed that VE/HXLPE particles displayed various shapes, such as spheroidal, flakes, bulks, rods, and fibrils, and their formation mechanism was discussed. Additionally, the Functional Biological Activity (FBA) of VE/HXLPE wear particles was calculated. The results demonstrated differences in particle sizes, shape distributions, and bioactivity between VE/HXLPE and UHMWPE, which indicates that VE/HXLPE particles had a lower likelihood of inducing osteolysis. This study holds promise for gaining deeper insights into the mechanical properties and the potential for bioactivity in VE/HXLPE as an artificial joint material.

Characteristics of bulletproof plate made from silkworm cocoon waste: Hybrid silkworm cocoon waste-reinforced epoxy/UHMWPE composite

Abstract This study aims to develop composite plates using silkworm cocoon waste- and hybrid silkworm cocoon waste-reinforced polymer composite using epoxy resin as a matrix to replace synthetic fibers in bulletproof plates. The fabrication involved mixing 70 g of silkworm cocoon waste with 240 g of resin and 70 g of ultra-high molecular weight polyethylene, followed by cold compression molding. Tensile and impact tests on the resulting samples, using a standardized 9 mm projectile, showed a tensile strength of 107.4 MPa and an elastic modulus of 1240.3 MPa. With a back face signature (BFS) of 21.25 mm, the samples effectively intercepted the projectile, satisfying the stringent U.S. National Institute of Justice standard 0101.06, which specifies a maximum BFS of 44 mm. In comparison with hemp woven materials, silkworm cocoon waste has proven to be a promising substitute for both tensile and impact evaluations, attracting considerable interest and underscoring its role as a reinforcing agent for national fiber. This research has significant implications for industries and applications requiring affordable, lightweight, and efficient safeguards against ballistic dangers. Ultimately, it contributes to the progress of ballistic protection methods by encouraging exploration into innovative, bio-inspired, and sustainable materials capable of achieving superior impact resistance.

Characterizing Surface Morphological and Chemical Properties of Commonly Used Orthopedic Implant Materials and Determining Their Clinical Significance.

The goal of the study was to compare the surface characteristics of typical implant materials used in orthopedic surgery and traumatology, as these determine their successful biointegration. The morphological and chemical structure of Vortex plate anodized titanium from commercially pure (CP) Grade 2 Titanium (Ti2) is generally used in the following; non-cemented total hip replacement (THR) stem and cup Ti alloy (Ti6Al4V) with titanium plasma spray (TPS) coating; cemented THR stem Stainless steel (SS); total knee replacement (TKR) femoral component CoCrMo alloy (CoCr); cemented acetabular component from highly cross-linked ultrahigh molecular weight polyethylene (HXL); and cementless acetabular liner from ultrahigh molecular weight polyethylene (UHMWPE) (Sanatmetal, Ltd., Eger, Hungary) discs, all of which were examined. Visualization and elemental analysis were carried out by scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS) and X-ray photoelectron spectroscopy (XPS). Surface roughness was determined by atomic force microscopy (AFM) and profilometry. TPS Ti presented the highest Ra value (25 ± 2 μm), followed by CoCr (535 ± 19 nm), Ti2 (227 ± 15 nm) and SS (170 ± 11 nm). The roughness measured in the HXL and UHMWPE surfaces was in the same range, 147 ± 13 nm and 144 ± 15 nm, respectively. EDS confirmed typical elements regarding the investigated prosthesis materials. XPS results supported the EDS results and revealed a high % of Ti4+ on Ti2 and TPS surfaces. The results indicate that the surfaces of prosthesis materials have significantly different features, and a detailed characterization is needed to successfully apply them in orthopedic surgery and traumatology.

A Novel growth guidance system for early onset scoliosis: a preliminary in vitro study

PurposeThe purpose of the study was to describe a novel growth guidance system, which can avoid metal debris and reduce the sliding friction forces, and test the durability and glidability of the system by in vitro test.MethodTwo major modifications were made to the traditional Shilla system, including the use of ultra-high molecular weight polyethylene (UHMWPE) gaskets to avoid direct contact between the screw and rod, and polishing the surface of the sliding part of the rod. We tested the durability of the system by a fatigue test, which the samples were test on the MTS system for a 10 million cycle of a constant displacement. Pre and post-testing involved weighing the UHMWPE gaskets and observing the wear conditions. The sliding ability were measured by a sliding displacement test. The maximum sliding displacement of the system was measured after a 300 cycles of dynamic compressive loads in a sinusoidal waveform.ResultsAfter the fatigue test, all the UHMWPE gaskets samples showed some of the fretting on the edge of the inner sides, but its still isolated and avoided the friction between the screws and rods. There was no production of metallic fretting around the sliding screws and rods. The average wear mass of the UHMWPE gaskets was 0.002 ± 0.001 g, less than 1.7% of the original mass. In the sliding test, the novel growth guidance system demonstrated the best sliding ability, with an average maximum sliding distance(AMSD) of 35.75 ± 5.73 mm, significantly better than the group of the traditional Shilla technique(AMSD 3.65 ± 0.46 mm, P < 0.0001).ConclusionIn conclusion, we modified the Shilla technique and designed a novel growth guidance system by changing the friction interface of sliding screw and rod, which may significantly reduce the metallic debris and promote spine growth. The fatigue test and sliding dislocation test demonstrated the better durability and glidability of the system. An in vivo animal experiment should be performed to further verify the system.

Ballistic performance and energy transfer of ultrahigh molecular weight polyethylene laminate

Soldier protection is crucial in contemporary localized conflicts, However, the impact response mechanism of UHMWPE laminate as the insert plate of ballistic helmet and bulletproof vest is still unclear. This study utilized 3D-DIC technology to analyze the impact response of UHMWPE laminates subjected to a 9 mm lead-core pistol bullet at a velocity of 334.93 m/s. The damage mode and response characteristics of the back surface were revealed; an effective numerical calculation method was established and could reveal the energy conversion process. The bullet penetrated the front face with 1.01 mm, resulting in a cross-shaped failure feature due to fiber bundle compression and aggregation. The numerical model confirmed its accuracy by comparing the height, width, and inplane strain distribution within the inplane of the bulge with experimental results. It further investigated the interaction between the bullet and the laminate, and energy transformation. The bullet's kinetic energy decreased by 80.64 %, in which the laminate absorbs 30.84 % of the bullet's energy as internal energy and 35.06 % as kinetic energy, meanwhile the bullet's internal energy increases by 11.77 %. The results show the damage mode and energy transformation of laminate, which provides theoretical support for revealing the impact response mechanism and improving the protective energy absorption efficiency.

Shish‐kebab structure evolution of HDPE/UHMWPE during hot drawing

AbstractUsing a solution‐mixing method, this research aimed to fabricate high‐density polyethylene (HDPE)/ultra‐high molecular weight polyethylene (UHMWPE) composite materials with uniform dispersion. By incorporating a small quantity of UHMWPE as a nucleating agent, additional contact points were introduced to enhance the crystallization rate of the HDPE matrix. Thermal stretching experiments were conducted on composite systems with varying UHMWPE contents and molecular weight additions at different temperatures. Elevating the stretching temperature was found to decrease the yield strain and yield strength, extend the stage of tensile plastic deformation, and diminish the overall mechanical properties of the composite material. Notably, stretching at temperatures ranging from 90 to 110°C accentuated the development of internal crystal orientation structures. Under low strain conditions, crystal slip was observed to be concentrated, with single crystals undergoing continuous stretching and breaking, resulting in a decrease in the long period. Conversely, at high strains, the induced formation of oriented lamellar structures was observed.Highlights Prepared HDPE/UHMWPE blends by UHMWPE with varying molecular weights. Analyzed the alterations in the HDPE/UHMWPE blends' internal crystal structure. Influence of UHMWPE addition, temperature on the evolution of crystal structure.

Improved processability for ultra‐high molecular weight polyethylene/polyolefin elastomer composites: Effect of ethylenevinyl acetate copolymer

AbstractPolyolefin elastomer (POE) films can be used as a matrix for ultra‐high molecular weight polyethylene (UHMWPE) fiber‐reinforced composites via a hot‐melt process. However, the low melting temperature of UHMWPE limits composite processing. Therefore, this study aimed to create a film by blending POE with ethylene vinyl acetate (EVA) to reduce the film's processing temperature. Morphological analysis revealed that due to limited compatibility, EVA appeared as droplets within the immiscible POE matrix. T‐Peel tests demonstrated increased self‐adhesion in both the POE/EVA films and the fiber‐reinforced composites with higher EVA content. However, the mechanical properties of POE/EVA films, including tensile properties and shore hardness, were reduced due to EVA having lower inherent properties. UHMWPE fiber‐reinforced composites were fabricated from these films. In composites, optimal tensile and flexural properties were observed at lower EVA content. Scanning electron microscopy analysis suggests that the POE/EVA films are sufficiently infiltrated at 10–20 wt% EVA content. As EVA content increased, the drop weight impact test indicated a reduction in the maximum impact load and an increase in impact energy, attributed to improved adhesion and a broader distribution of impact load across the interface.Highlights Polyolefin elastomer/ultra‐high molecular weight polyethylene composites' properties were studied with varying ethylene vinyl acetate (EVA) additive content. Add EVA to improve film impregnation when forming composites Increase in impregnation affects increase in properties of composites. Characterization shows that the optimal EVA content is 10–20 wt%.

Investigation of contact behavior on a model of the dual-mobility artificial hip joint for Asians in different inner liner thicknesses.

The four components that make up the current dual-mobility artificial hip joint design are the femoral head, the inner liner, the outer liner as a metal cover to prevent wear, and the acetabular cup. The acetabular cup and the outer liner were constructed of 316L stainless steel. At the same time, the inner liner was made of ultra-high-molecular-weight polyethylene (UHMWPE). As this new dual-mobility artificial hip joint has not been researched extensively, more tribological research is needed to predict wear. The thickness of the inner liner is a significant component to consider when calculating the contact pressure. To make use of finite element analysis to gain a better understanding of the contact behavior in various inner liner thicknesses on a new model of a dual-mobility artificial hip joint, with the ultimate objective of determining the inner liner thickness that was most suitable for this particular type of dual-mobility artificial hip joint. In this study, the size of the femoral head was compared between two diameters (28 mm and 36 mm) and eight inner liner thicknesses ranging from 5 mm to 12 mm. Using the finite element method, the contact parameters, including the maximum contact pressure and contact area, have been evaluated in light of the Hertzian contact theory. The simulation was performed statically with dissipated energy and asymmetric behavior. The types of interaction were surface-to-surface contact and normal contact behavior. The maximum contact pressures in the inner liner (UHMWPE) at a head diameter of 28 mm and 36 mm are between 3.7-13.5 MPa and 2.7-10.4 MPa, respectively. The maximum von Mises of the inner liner, outer liner, and acetabular cup are 2.4-11.4 MPa, 15.7-44.3 MPa, and 3.7-12.6 MPa, respectively, for 28 mm head. Then the maximum von Mises stresses of the 36 mm head are 1.9-8.9 MPa for the inner liner, 9.9-32.8 MPa for the outer liner, and 2.6-9.9 MPa for the acetabular cup. A head with a diameter of 28 mm should have an inner liner with a thickness of 12 mm. Whereas the head diameter was 36 mm, an inner liner thickness of 8 mm was suitable. The contact pressures and von Mises stresses generated during this research can potentially be exploited in estimating the wear of dual-mobility artificial hip joints in general. Contact pressure and von Mises stress reduce with an increasing head diameter and inner liner's thickness. Present findings would become one of the references for orthopedic surgery for choosing suitable bearing geometric parameter of hip implant.

Effect of multi-scale fillers on the tribological behavior of UHMWPE composites in water-lubricated contacts

This study investigates the impact of graphite, hexagonal boron nitride and short carbon fibers, acting as micro- and nano-fillers, on the tribological performance of ultra-high-molecular-weight polyethylene (UHMWPE) hybrid composites. The tribological performance is evaluated under boundary-lubrication conditions with distilled water at contact pressures in the range from 5 and 15 MPa. The fillers were found to work synergistically, with the best performance recorded when the compositions incorporated fillers of all scales. The most effective composite, consisting of short carbon fibers, micro-scale graphite, micro-scale hBN and nano-scale hBN, reduced the coefficient of friction by 75 %, reaching a value of 0.06, and the specific wear rate by two orders of magnitude to 2 × 10−7 mm3/Nm, compared to pure UHMWPE. The fillers' size also played an important role. Composites with nano-boron nitride led to 40 % lower friction compared to micro-scale fillers only. However, all the fillers reduced the amount of abrasive wear, especially the boron nitride, as a consequence of the tribochemical reaction between the boron nitride and water at the interface. Additionally, the formation of a transfer film was observed on the steel discs, with only short carbon fibers and graphite contributing to its formation from among the fillers used.

Shock Response and Dynamic Failure of High Density-(HDPE) and Ultra-High Molecular Weight Polyethylene (UHMWPE)

Shock Response and Dynamic Failure of High Density-(HDPE) and Ultra-High Molecular Weight Polyethylene (UHMWPE)

Influence of Oxygen/Argon/Nitrogen multi-component plasma modification on interlayer toughening of UHMWPE fiber reinforced composites

The study reveals the influence of glow discharged three gas sources of Oxygen/Argon/Nitrogen plasma modification on interlayer toughening of ultra-high molecular weight polyethylene (UHMWPE) fiber reinforced composite. The failure modes under bending, tensile and interlayer fracture toughness testing were analyzed through acoustic emission (AE) technology. The results showed that Oxygen/Argon/Nitrogen multi-component plasma modified fiber introduced more hydrophilic groups such as hydrogen and hydroxyl groups, and significantly enhanced the binding of fiber and matrix. The GⅠC (Mode-I interlaminar fracture toughness) of multi-component plasma modified composites exhibited increased by 61.67 %, 40.88 % and 18.01 % compared to untreated, Oxygen and Oxygen/Argon plasma, respectively, while GⅡC (Mode-II interlaminar fracture toughness) increased by 38.57 %, 25.57 % and 23.09 %. AE cluster analysis exhibited that multi-component plasma modified composites formed an energy dissipation mechanism dominated by fiber breakage. Additionally, the oxygen, argon, and nitrogen plasma modification have a synergistic effect on interlayer toughening.

Melt-crystallization and self-nucleation of UHMWPE/bi-HDPE blends: The combined role of composition and molecular weight

Blends of bi-modal high-density polyethylene (bi-HDPE) and ultra-high molecular weight polyethylene (UHMWPE) with varying content (0–30 wt%.) and different molecular weights (MWs) (2.2, 3.5, and 4.5 M g/mol) of UHMWPE were prepared. The effect of UHMWPE content, MW, and their interplay on the microstructure, nucleation, and crystallization behavior of bi-HDPE was examined through rheology, scanning electron microscopy, and differential scanning calorimetry. The results revealed that UHMWPE serves as a partially miscible nucleating agent, effectively dispersing in the bi-HDPE matrix up to 5 wt%, thereby promoting the transition from randomly dispersed lamellae to a spherulitic morphology. The nucleating effect saturated when the UHMWPE content reached 10 wt%, leading to a diminished spherulitic structure. Beyond 10 wt% of UHMWPE, an anti-nucleation effect with segregated crystalline regions emerged. Isothermal kinetics analysis also revealed the highest crystallization rate at the optimum UHMWPE content of 5 wt%, where the critical nucleation energy barrier and fold-surface free energy were minimized. Apart from the UHMWPE content, signs of nucleation enhancement were slightly more pronounced in the bi-HDPE blend with the lowest molecular weight of UHMWPE. This phenomenon results from increased concentration fluctuations due to the larger interfacial area, as postulated from entanglement density measurements. For the first time, self-nucleation (SN) analysis revealed that the incorporation of 5 wt% of UHMWPE into bi-HDPE resulted in a wider Domain II width, indicating an increased memory effect. Notably, the crystalline memory was more pronounced in the blend containing UHMWPE with the MW of 2.2 M g/mol, exhibiting the super-nucleating effect with the highest nucleation efficiency of 218 %.

“Like binding a book”: Interfacial improvement of pre-melted ultrahigh molecular weight polyethylene by pulse vibration molding

Ultrahigh molecular weight polyethylene (UHMWPE) is widely used in industrial, military, and civilian applications owing to its excellent properties. However, the high entanglement degree of UHMWPE melt leads to great difficulties in diffusion and crystallization, which causes poor interfacial strength and mechanical properties of pre-melted UHMWPE, restricting its high-quality processing and high-value recycling. To this end, we propose a rapid interface stitching technology with a pulsed vibration force driving free volume homogenization and chain segment orientation. For the first time, pulse vibration molding (PVM) is applied for the hot-pressing of pre-melted UHMWPE, successfully realizing the interface stitching and product strengthening. Compared with those of the convention molding (CM) samples at 180 °C, the interfacial adhesive fracture toughness of the adhesive samples processed using PVM is increased by 105.9 % and the work of tension of the recycled samples processed using PVM is also increased by 49.09 %, respectively. The fracture strength of the PVM recycled samples at 180 °C reaches 91.77 % of that of the pure samples and the yield strength is also higher, which significantly enhances the recycling of UHMWPE. The characterization results of the interfacial molecular chain entanglement and crystallization show that PVM strengthens the molecular chain diffusion and induces crystallization by promoting the orientation of chain segments, especially at the interface. Consequently, we believe that the proposed technology can play a significant role in the UHMWPE processing methods that involve surface healing.

Effect of Nitrate Acid Treated Dolomite on the Tensile Properties of Ultra-High Molecular Weight Polyethylene (UHMWPE) Composites

Ultra-High Molecular Weight Polyethylene (UHMWPE) polymers have been used in biomedical applications due to its biocompatibility, durability, toughness and high wear resistance. To enhance the mechanical properties, various types of minerals are commonly utilized as fillers in UHMWPE. One of the minerals is dolomite, which has been recognized as a valuable mineral with versatile applications, particularly in the field of biomedical applications. This paper presents the tensile properties of UHMWPE composites that filled with dolomite and treated-dolomite at various filler loading (i.e., 1-5 wt.%). Nitric acid and diammonium phosphate were used to treat the dolomite. From the results, the peaks of the FTIR spectrum displays carbonate (CO3–2), phosphate (PO4–3) and hydroxyl (OH–) groups in the ct-dolomite powder sample while the XRD pattern reveals that using dolomite treated with 1M nitric acid resulted in the presence of calcium hydroxide phosphate (Ca10(PO4)5(OH)) and MgO. For tensile strength, UHMWPE/ct-dolomite composites show better tensile strength than the pure UHMWPE composites. Treated improve the dolomite filler and resulted in significantly better matrix-filler interfacial interactions and improve the properties.

Design of an add-on ceramic composite armour against 14.5 × 114 mm API/B32 projectile for the armoured vehicles and investigation of the ballistic performance of the armour

Abstract A ceramic/composite add-on armour system with innovative ceramic geometry (cylindrical) against 14.5 × 114 mm API/B32 projectile was developed and ballistic performance of the armour was investigated both experimentally and numerically. Numerical analysis was used to calculate exit velocities of the projectile after passing through the ceramic/composite layer (before penetrating the Armox 500T which simulates hull structure of an armoured vehicle) and also contributed to the selection of optimum ceramic thickness. The calculated projectile velocity-time curves (from numerical analysis) for three different ceramic thicknesses are given comparatively in the study. The curve characteristics are the same for three different analyses. The duration of the total absorption of the projectile energy is about 0.2 microseconds (ms). There were differences in the transmission of the stress wave and the delamination in the Ultra-High-Molecular-Weight Polyethylene (UHMWPE) layers differed as ceramic thickness increases. The separation between the layers varied with the change in projectile energy. As a result of the ballistic test, the armour prevented 14.5 × 114 mm API/B32 ammunition with desired damage mechanisms. In the x-ray image taken after the shootings, it was seen that the ceramic damage was local which enhanced multi-hit resistance capability and the geometry of the cylindrical alumina played an important role in the localization of the ceramic zone damage during the projectile penetration process. Due to this cylindrical ceramic geometry, the projectile moving on after the moment of impact constantly encounters a curved and new surface, and thus it is deflected and exposed to more wear. The areal density of the armour was also reduced by using the UHMWPE (which is one of the composite material whose fibres have the lowest density and good mechanical properties) composite plate as the backing plate.

Enhancing Wear Resistance of UHMWPE Composites with Micro MoS2 and Nano Graphite: A Taguchi-DOE Approach.

This study presents an in-depth investigation into the wear characteristics of ultrahigh-molecular-weight polyethylene (UHMWPE) composites reinforced with microsized MoS2 and nanosized graphite particles. The objective is to enhance the wear resistance of the UHMWPE by examining the effects of various parameters and optimizing the wear performance. To achieve this goal, wet wear tests were conducted under controlled conditions, and the results were compared between composites with micro MoS2 and nano graphite reinforcements. The Taguchi method was employed to design the experiments (DOE) using an L9 orthogonal array. Four key parameters, namely, reinforcement percentage, load, speed, and track radius, were varied systematically to analyze their impact on wear characteristics, including wear rate, frictional forces, and the coefficient of friction (COF). The data obtained from the experiments were subjected to analysis of variance (ANOVA) to identify the significant factors affecting wear behavior. Subsequently, the optimal wear parameters were determined through regression analysis, allowing for the prediction of wear characteristics under the optimum conditions. This research not only provides insights into the comparative performance of micro MoS2 and nano graphite reinforcements in UHMWPE composites but also offers a comprehensive approach to optimizing wear resistance by employing advanced statistical and experimental techniques. The findings contribute to the development of more durable and wear-resistant materials with potential applications in various industries, such as those investigated in the study, which are commonly employed, such as automotive, aerospace, medical devices, or manufacturing.

Bimodal coaxial fiber sensor for simultaneous strain and temperature sensing for composite manufacturing process

Coaxial structured fibers have gained significant attention in sensor applications due to their design flexibility and ability for multifunctionality. However, the complex and thicker structure of a sensor can lead to stress concentration and signal interference when utilized for strain monitoring in composite manufacturing processes. To address this issue, we propose a bimodal coaxial fiber sensor capable of simultaneous temperature and strain measurement during composite cure and strain monitoring, while preserving the mechanical properties of the fabricated composites. To achieve bimodal sensing, we employ a multi-shell structure consisting of a multi-conductive layer with varying concentrations of multiwalled carbon nanotubes and a PEDOT:PSS layer, applied to a creep-enhanced ultra-high molecular weight polyethylene core fiber using a simple dip-coating method. The bimodal coaxial fiber sensor exhibits a high gauge factor (>4.1), stable cyclic tensile response (>1000 cycles), and linear response to stepwise temperature cycles. Moreover, the sensor demonstrates high sensing accuracy (<3% error) in cure strain monitoring and maintains the fracture toughness of the composite (<1% discrepancy) wherein it is embedded. These results confirm the significant potential of the bimodal coaxial fiber sensor for various applications in the composite industry and other fields.