Search Results (38)

To address the critical challenge of 0–100 Hz low-frequency vibration control for marine hydraulic pipelines, this paper proposes a dedicated fiber-reinforced magnetorheological elastomer (MRE) isolator and a genetic algorithm-optimized fuzzy control strategy utilizing the magnetically tunable properties of MREs. An upper-lower split-type isolator is designed to suppress axial and radial vibrations through the shear and Compression Modes of MRE, respectively, and a two-degree-of-freedom (2-DOF) dynamic model is established to analyze the effects of mass ratio and natural frequency ratio on the system’s amplitude magnification factor. A Mamdani-type fuzzy controller, with acceleration error and its rate of change as inputs and control voltage as output, is optimized via a genetic algorithm. Simulation and experimental results show that 31–56.5% amplitude attenuation is achieved under 25–35 Hz single-frequency excitation; 12 dB isolation in the 5–23 Hz band at the input end and a maximum 15 dB isolation in multiple bands for the suspended pipeline section are obtained without external forced excitation; and efficient 0–100 Hz full-band isolation is realized at an applied current of 1.5 A. This work verifies the effectiveness of the proposed scheme for low-frequency vibration control of marine hydraulic pipelines. Full article

Numerical predictions of the wrinkling behavior of biaxially fiber-reinforced elastomer sheets are carried out under consideration of finite deformations. The Holzapfel–Gasser–Ogden material model is used to account for the anisotropic hyperelastic material behavior of the sheets, where material parameters are identified based on experimental data of tensile tests from literature. A Finite Element Method-based simulation strategy is presented to extract critical loading conditions and to access the postbuckling response using geometrical imperfections. Depending on the layup and aspect ratio of the sheets, wrinkling onset was predicted for global stretches between 10% and 25%. For sheets with fiber orientations [±45°] wrinkling is predicted at larger global stretches than for sheets with fiber orientations of $[+{30}^{\circ }/-{60}^{\circ }]$ for the same aspect ratio. Furthermore, it is shown that short sheets have a tendency towards symmetric wrinkling patterns whereas for long sheets asymmetric wrinkles are more likely to occur. Comparison of the numerical predictions with experiments from the literature shows that the geometrical characteristics of the wrinkles, such as wavelengths and amplitudes, can be well predicted. Far into the postbuckling regime, the deviations of the predicted wrinkling amplitudes and their experimental counterparts are around 30% or less. Full article

Bicycle tires and inner tubes constitute a growing waste stream mainly composed of natural rubber, butyl rubber, synthetic elastomers, carbon black, and reinforcing materials. Their multi-material structure and highly crosslinked networks make their recycling challenging, yet efficient recovery is essential for advanced circular economy practices. This review summarizes the current and emerging strategies for recycling bicycle tires and inner tubes. It first outlines the materials and additives present in tire casings and butyl inner tubes, which determine their recycling behavior. Mechanical pre-processing methods, including shredding, grinding, and fiber/steel separation, are presented as essential feedstock preparation steps. Thermochemical approaches, such as pyrolysis and thermolysis, are discussed with emphasis on producing value-added fractions, including pyrolysis oil, recovered carbon black, and fuels. Solvent-based feedstock recycling and chemical dissolution are highlighted as promising routes for selective recovery of rubber polymers and additives. Physical, chemical, and biological devulcanization methods are also reviewed for their potential to restore partial processability to reuse reclaimed rubber. Finally, current and prospective applications of recycled materials are discussed, and key challenges with future research needs are identified, including improving devulcanization efficiency, expanding collection systems, and increasing the value of recovered products. Full article

This study evaluates the tribological behavior of two elastomeric sealing materials—EPDM and TPV—sliding against 30 wt.% glass fiber-reinforced polyamide 66 (PA66GF30), a composite widely used in structural and guiding components. The application context is low-leakage valve systems in polymer electrolyte membrane fuel cells (PEMFCs), particularly on the cathodic (air) side, where dry contact and low-friction sealing are critical. Pin-on-disk tests were conducted under three normal loads (1, 3, and 6 N) and sliding speeds of approximately 0.05, 0.10, and 0.15 m/s (92, 183, and 286 RPM). The coefficient of friction (CoF), mass loss, and wear morphology were analyzed. TPV generally exhibited lower and more stable friction than EPDM, with CoF values exceeding 1.0 at 1 N but falling within 0.32–0.52 under typical operating conditions (≥3 N). EPDM reached a maximum mass loss of 0.060%, while TPV remained below 0.022%. Microscopy revealed more severe wear features in EPDM, including tearing and abrasive deformation, whereas TPV surfaces displayed smoother, more uniform wear consistent with its dual-phase morphology. These findings support the selection of TPV over EPDM in dry-contact sealing interfaces involving composite counterfaces in PEMFC systems. Full article

This review explores the evolving landscape of sustainable textile manufacturing, with a focus on rubber-based materials for various industrial applications. The textile and rubber industries are shifting towards eco-friendly practices, driven by environmental concerns and the need to reduce carbon footprints. The integration of sustainable textiles in rubber-based products, such as tires, conveyor belts, and defense products, is becoming increasingly prominent. This review discusses the adoption of natural fibers like flax, jute, and hemp, which offer biodegradability and improved mechanical properties. Additionally, it highlights sustainable elastomer sources, including natural rubber from Hevea brasiliensis and alternative plants like Guayule and Russian dandelion, as well as bio-based synthetic rubbers derived from terpenes and biomass. The review also covers sustainable additives, such as silica fillers, nanoclay, and bio-based plasticizers, which enhance performance while reducing environmental impact. Textile–rubber composites offer a cost-effective alternative to traditional fiber-reinforced polymers when high flexibility and impact resistance are needed. Rubber matrices enhance fatigue life under cyclic loading, and sustainable textiles like jute can reduce environmental impact. The manufacturing process involves rubber preparation, composite assembly, consolidation/curing, and post-processing, with precise control over temperature and pressure during curing being critical. These composites are versatile and robust, finding applications in tires, conveyor belts, insulation, and more. The review also highlights the advantages of textile–rubber composites, innovative recycling and upcycling initiatives, addressing current challenges and outlining future perspectives for achieving a circular economy in the textile and rubber sectors. Full article

This paper investigates the use of glass and carbon fiber-reinforced polymer composites with epoxy matrices for non-pneumatic tires (NPTs), as an alternative to conventional elastomer-based designs. A novel NPT design approach was developed in three steps: (i) a finite element model with isotropic material properties was constructed to identify suitable spoke geometries; (ii) an anisotropic parametric study quantified key parameters influencing the load-bearing capability of two selected concepts from step (i); and (iii) a preferred version was chosen from step (ii) and evaluated under multiple load cases to ensure it met all requirements. The final tire design incorporates thick spiral spokes superimposed with a cosine-like function, showcasing the strengths and limitations of non-elastomeric reinforced polymers for NPT design. This study provides innovative insights into reducing the mass of NPTs and demonstrates the potential of fiber-reinforced polymer composites to achieve more lightweight, durable, and efficient NPT designs in comparison to pneumatic ones. Full article

This study addresses the high cost of traditional dental impression materials by introducing a novel composite material reinforced with wheat bran powder, aiming to reduce expenses while maintaining suitable mechanical performance. Tensile and compression test specimens were prepared according to the ASTM D412 and ASTM D575 standards, respectively, to evaluate the mechanical properties of the pure elastomer and the wheat-bran-reinforced composite. Comparative t-tests were conducted to analyze the tensile and compression strengths of both materials, focusing on their cost-effectiveness and suitability for dental applications. The results demonstrate that the wheat-bran-reinforced composite exhibits compression strength (105 MPa) comparable to that of the pure elastomer while offering controlled deformation and enhanced stiffness under compression. Although the composite shows reduced tensile strength (7 MPa vs. 11 MPa), its performance remains adequate for applications requiring moderate tensile properties. Notably, the new material reduces costs by approximately 50%, making it an economical and sustainable alternative for dental impression materials. This innovation aligns with sustainable practices by incorporating natural fibers and offers dentists a cost-effective solution without compromising on performance. Full article

Modified basalt microfiber-reinforced polyurethane elastomer composites were prepared by a semi-prepolymer method with two different silane coupling agents (KH550 and KH560) in this study. Infrared spectroscopy was used to quantify the degree of microphase separation and analyze the formation of hydrogen bonding in polyurethane. The interfacial surface and the morphology of fibers and composites from tensile fracture were examined by a scanning electron microscope. Further measurements were performed on an electronic universal testing machine for characterizing the mechanical properties of composites. Moreover, the loss factor and transmission loss of composite materials were obtained from dynamic thermomechanical analysis and acoustic impedance tube, respectively. The suitable concentrations in the modification of basalt fibers were established at 1% for KH550 and 1.5% for KH560. The best overall performance was obtained in KH550-BMF/PUE group, as the properties increased by 31% in tensile strength, 37% in elongation at break, and 21% in acoustic insulation. Full article

Polyurethane incorporated with nanofillers such as carbon nanotubes, basalt fibers, and clay nanoparticles has presented remarkable potential for improving the performance of the polymeric composites. In this study, the halloysite nanofiller-reinforced polyurethane elastomer composites were prepared via the semi-prepolymer method. The impact of different halloysites (halloysite nanotubes and halloysite nanoplates) in polyurethane composites was investigated. Scanning electron microscopy, X-ray diffraction, infrared spectroscopy, electronic universal tensile testing, and acoustic impedance tube testing were employed to characterize the morphology, composition, phase separation, mechanical properties, and sound insulation of the samples. The composite fabricated with 0.5 wt% of halloysite nanotubes introduced during quasi-prepolymer preparation exhibited the highest tensile strength (22.92 ± 0.84 MPa) and elongation at break (576.67 ± 17.99%) among all the prepared samples. Also, the incorporation of 2 wt% halloysite nanotubes into the polyurethane matrix resulted in the most significant overall improvements, particularly in terms of tensile strength (~44%), elongation at break (~40%), and sound insulation (~25%) within the low-frequency range of 50 to 1600 Hz. The attainment of these impressive mechanical and acoustic characteristics could be attributed to the unique lumen structure of the halloysite nanotubes, good dispersion of the halloysites in the polyurethane, and the interfacial bonding between the matrix and halloysite fillers. Full article

Dielectric elastomer actuators (DEAs) have gained significant attention due to their potential in soft robotics and adaptive structures. However, their performance is often limited by their in-plane strain distribution and limited mechanical stability. We introduce a novel design utilizing fiber reinforcement to address these challenges. The fiber reinforcement provides enhanced mechanical integrity and improved strain distribution, enabling efficient energy conversion and out-of-plane displacement. We discuss an analytical model and the fabrication process, including material selection, to realize fiber-reinforced DEAs. Numerical simulations and experimental results demonstrate the performance of the fiber-reinforced equibiaxial DEAs and characterize their displacement and force capabilities. Actuators with four and eight fibers are fabricated with 100 $\mathsf{\mu }$m and 200 $\mathsf{\mu }$m dielectric thicknesses. A maximal out-of-plane displacement of 500 $\mathsf{\mu }$m is reached, with a force of 0.18 N, showing promise for the development of haptic devices. Full article

A cost-effective solution to the problems that the automotive industry is facing nowadays regarding regulations on emissions and fuel efficiency is to achieve weight reduction of automobile parts. Glass fiber-reinforced polymers are regularly used to manufacture various components, and some parts may also contain thermoplastic elastomers for toughness improvement. This work aimed to investigate the effect of styrene-(ethylene-co-butylene)-styrene triblock copolymer (E) and treated fly ash (C) on the morphological, thermal, and mechanical properties of long glass fiber (G)-reinforced polypropylene (PP). Results showed that the composites obtained through melt processing methods presented similar thermal stability and improved (nano)mechanical properties compared to 25–30 wt.% G-reinforced PP composites (PP-25G/PP-30G). Specifically, the impact strength and surface hardness were greatly improved. The addition of 20 wt.% E led to a 25–39% increase in impact strength and surface elasticity, while the addition of 6.5 wt.% C led to a 16% increase in surface hardness. The composite based on 25 wt.% G, 6.5 wt.% C, and 20 wt.% E presented the best-balanced properties (8–17% increase in impact strength, 38–41% increase in axial strain, and 35% increase in surface hardness) compared with PP-30G/PP-25G. Structural and morphological analysis confirmed the presence of a strong interaction between the components that make the composites. Based on these results, the PP–G–E–C composites could be presented as a viable material for automotive applications. Full article

Fiber-reinforced elastomeric isolators (FREIs) are composite devices consisting of an alternation of elastomer layers and fiber reinforcement layers. They have mechanical properties comparable to those of conventional Steel-Reinforced Elastomeric Isolators (SREIs). The mechanical and construction characteristics of FREIs, together with their lower cost, make them potentially usable on a large scale. However, for their actual use, it is necessary to take into account the current regulations regarding seismic isolation. The application of FREIs provides the absence of anchoring to the structure, but the European Technical Standard UNI EN 15129 requires that the isolators are attached to the structure by mechanical fastening only. In this research work, a constraint device that fulfills this requirement but, at the same time, does not significantly alter the mechanical behavior of FREIs is investigated. The properties of the selected device and its installation method are presented. The results of both a simple compression test and a combined compression and shear test performed on two isolators reinforced by quadri-directional carbon fiber fabrics and two isolators reinforced by bi-directional fabrics are presented. The tests were performed in the absence and presence of the constraint device in order to investigate the modifications produced by the device. Full article

A non-pneumatic tire (NPT) overcomes the shortcomings of a traditional pneumatic tire such as wear, punctures and blowouts. In this respect, it shows great potential in improving driving safety, and has received great attention in recent years. In this paper, a carbon fiber-reinforced polyethylene terephthalate (PET/CF) honeycomb is proposed as a support structure for NPTs, which can be easily prepared using 3D printing technology. The experimental results showed that the PET/CF has high strength and modulus and provides excellent mechanical properties. Then, a finite element (FE) model was established to predict the compression performance of auxetic honeycombs. Good agreement was achieved between the experimental data and FE analysis. The influence of the cell parameters on the compressive performance of the support structure were further analyzed. Both the wall thickness and the vertically inclined angle could modulate the mechanical performance of the NPT. Finally, the application of vertical force is used to analyze the static load of the structure. The PET/CF honeycomb as the support structure of the NPT showed outstanding bearing capacity and stiffness in contrast with elastomer counterparts. Consequently, this study broadens the material selection for NPTs and proposes a strategy for manufacturing a prototype, which provides a reference for the design and development of non-pneumatic tires. Full article

The treatment of waste plastics has gradually become a hot topic in the current scientific community. In response to the needs for high-impact performance R-PP-based composites, carbon fiber (CF)-reinforced polyolefin elastomer (POE)/recycled polypropylene (R-PP) composite (CF/POE/R-PP) was prepared by the mechanical blending method, and its mechanical and thermal properties were systematically studied. It was found that the CF could effectively improve the bending and notch impact strength as well as enhance the thermal stability of POE/R-PP. Furthermore, a stable and dispersed composite interface formed by the combination of maleic anhydride-grafted polypropylene (PP-g-MAH) with the surface of CF and the fusion alkyl chains in R-PP and POE further enhanced the CF’s reinforcing effect. As a result, the addition of 9 wt.% CF successfully improved the heat resistance of the composite material, and the residual carbon content increased by 97.84% after sintering. The composite toughening of POE and CF effectively improved the impact strength of the composite material, with a maximum increase of over 1000%. This study ultimately resulted in a high-impact-resistant composite material. Full article

This study addresses the challenge of achieving foam with a high expansion ratio and poor mechanical properties, caused by the low melt viscosity of semi-crystalline polypropylene (PP). We systematically employ a modification approach involving blending PP with polyolefin elastomers (POE), irradiation crosslinking, and fiber reinforcement to prepare fiber-reinforced crosslinked PP/POE composite foam. Through optimization and characterization of material composition and processing conditions, the obtained fiber-reinforced crosslinked PP/POE composite foam exhibits both low density and high performance. Specifically, at a crosslinking degree of 12%, the expansion ratio reaches 16 times its original value, and a foam density of 0.057 g/cm³ is reduced by 36% compared to the non-crosslinked PP/POE system with a density of 0.089 g/cm³. The density of the short-carbon-fiber-reinforced crosslinked sCF/PP/POE composite foam is comparable to that of the crosslinked PP/POE system, but the tensile strength reaches 0.69 MPa, representing a 200% increase over the crosslinked PP/POE system and a 41% increase over the non-crosslinked PP/POE system. Simultaneously, it exhibits excellent impact strength, tear resistance, and low heat shrinkage. Irradiation crosslinking is beneficial for enhancing the melt strength and resistance to high temperature thermal shrinkage of PP/POE foam, while fiber reinforcement contributes significantly to improving mechanical properties. These achieve a good complementary effect in low-density and high-performance PP foam modification. Full article