Study of tensile, hardness, and compressive properties of prosthetic pylon made of ramie and carbon/glass hybrid composite materials

Hybrid carbon fiber and glass fiber reinforced thermoset composites are commonly used in structural applications throughout the energy, aerospace, automotive, and marine industries. The differing fiber types can be combined into a hybrid composite with the intent to efficiently utilize the beneficial properties of each type of reinforcement. The fiber fraction of each individual fiber type influences the mechanical properties of the overall composite. Measurement of the fiber fraction of each individual fiber type allows understanding and prediction of the mechanical properties as well as a method of quality control in manufacturing. A combination of a carbonization in nitrogen method for the measurement of fiber content in carbon fiber reinforced composites and an oxidation method to measure the glass fiber content are used for the first time. It has been demonstrated that the approach is effective at measuring the carbon fiber and glass fiber contents in hybrid glass and carbon fiber thermoset composites in both epoxy and vinyl ester resin systems.

Compared to traditional prosthetic pylon materials (Aluminum, Titanium, or Stainless steel.), composite prosthetic pylon materials are used instead of metals. Vacuum bagging technique was adopted for the preparation of specimens made of Poly methyl methacrylate (PMMA) as matrix with constant Perlon layers and different number of Hybrid (Carbon + Glass) fibers layers as reinforcement materials at (±45º&0º/90º) orientation relative to applied load. Also the finite element method (ANSYS-15) were used by create a model of prosthetic pylon and applied compressive load at heel strike step from gait cycle to known the critical buckling stress. The experimental and numerical results shown that the tensile strength, modulus of elasticity, and critical buckling stress increases with increasing number of Hybrid fibers layers, that equal to (145 MPa, 6.25 GPa, and 670 MPa) respectively, and the percentage of increase in tensile strength, modulus of elasticity, and critical buckling stress for specimen with three Hybrid (Carbon + Glass) layers and Perlon layers in PMMA resin compared with pure PMMA specimen was (302.7% , 300% & 257.22%) respectively, at (0º/90º) fibers orientation relative to tensile force.

A new attempt development of new hybrid composite materials has been studied. Increasing the mechanical and physical properties of composite materials to lower their weight and cost is the most frequent problem in engineering projects. This study's goal is to enhance the mechanical and physical characteristics of composite materials. Also due to this, hybrid composite materials have received recent attention. In this work, hybrid composite materials were created to enhance mechanical and physical characteristics. In this investigation, glass fiber and mica fiber were both employed as synthetic and natural fibers, respectively. The influence of mica as natural fiber with glass fiber as synthetic reinforcement by weight percent (wt%) on the mechanical properties of hybrid composite materials were investigated. Epoxy resin (thermosetting polymer) reinforced by various wt % of glass fiber/mica fiber, such as (0-0, 15-0, 10-5, 7.5-7.5, 5-10, 0-15 %), as well as samples created by hand lay-up method. In addition, glass fiber and mica fiber in long fiber unidirectional form are utilized; mechanical properties such as tensile, flexural and impact strength have been tested. As the results of this study, both glass fiber and mica fiber increased mechanical properties, although glass fiber has a greater effect than mica fiber but also using mica fiber make great improvement between 26% to 67%. Composites reinforced with 15% glass fiber had a better value of mechanical properties compared to others. Additionally, the hybrid composite made of glass fiber and mica fiber performed well in all tests, enhanced mechanical characteristics, which decreased the cost of making composites.

ABSTRACTMany concrete structures, such as buildings, civil structures, or transport facilities, have an enormous need for rehabilitation. The defects have a critical influence on the resistance and durability of these structures. This study evaluates the effectiveness of strengthening reinforced concrete structures by bonding natural fiber composite materials (hemp fiber fabrics [HFF]) mixed with synthetic fibers (carbon fiber reinforced polymer [CFRP] or Glasse fiber reinforced polymer (GFRP) composites) using epoxy‐based adhesives to increase their mechanical strength and extend the lifespan of the structures. This strengthening consists of bonding a composite sheet based on natural fiber fabric to the judiciously targeted outer surface of the reinforced concrete structure. From a sustainable development perspective, replacing synthetic fibers as reinforcement with vegetal fiber plants is the first step in respecting environmental issues. This paper focuses on experimental investigations on reinforced concrete specimens (33 in all) considered strengthened by different composite mixes between natural and synthetic composite fibers. The crack propagation behavior and the influence of adhesive thickness were investigated. Considering that the adhesively bonded composite materials reduce the stress intensity at the crack tip and, therefore, increase the remaining lifetime of the concrete structure. In fact, the experimental results showed an increase in ultimate load in flexural strength from 65% to 104% of strengthened concrete specimens with hybrid (hemp and glass fiber fabrics) composite plate and from 117% to 163% of strengthened concrete specimens with hybrid (hemp and carbon fiber fabrics) composite plate, compared to the control concrete specimen without strengthening.

Producing clean water via renewable solar energy and available low-cost natural resources is one of paramount issues for the near future sustainable cleaner production theme to promote civilization. This work investigates the transient behavior of a solar-driven clean water extraction system from air by various desiccant natural and hybrid composite materials. Different single composite desiccant materials, hybrid single composite desiccant material, and hybrid multi-layers composite desiccant materials were examined using an efficient design of a solar glass box with four glass faces and square base setup. Nine different single composite desiccant materials were compared for water production from atmospheric air considering jute, wool, cotton, and maize starch host materials. The effect of CaCl2 solution concentration on the hybridization of such materials was also investigated to examine and optimize their water productivity efficiency. Thirteen hybrid multi-layer starch-based composite desiccant material types were utilized. Different layer combinations and weight percentages of hybrid composite desiccant materials were optimized based on the performance in the single hybrid composites stages including wool/CaCl2/starch, jute/CaCl2/starch, and cotton/CaCl2/starch. Results have indicated that the transient behavior of water productivity of composite desiccants increased as the wool percentage by mass in the composite has been increased. The transient behavior of water productivity of both single and hybrid multi-layer composites reached its maximum at 1:00 o'clock PM. The quality of extracted water was analyzed using total dissolved solids (TDS) test and found to be within the excellent category of clean water suitable for human being. Water generated from the samples that contain only natural fibers and starch was the cleaner and non-toxic.

7 - Investigation of mechanical testing on hybrid composite materials

This research investigates the biocompatibility, mechanical strength, and tribological properties of a hybrid composite material composed of high-density polyethylene (HDPE), hydroxyapatite (HAp), and titanium dioxide nanoparticles (Ti ). The study explores the microstructural characteristics of the composite material using scanning electron microscopy (SEM), transmission electron microscopy (TEM), and X-ray diffraction (XRD). Samples of HDPE-30%HAp with varying concentrations of Ti (5, 10, 15, and 20%) were prepared and extruded using a twin-screw machine. The hybrid composite materials underwent mechanical tests (tensile, flexural, and hardness), tribological tests (friction and wear rate), and antibacterial tests (resistance to Escherichia coli and Staphylococcus aureus bacteria). The results indicate that the optimal hybrid composite sample was HDPE-30%HAP-10% Ti , which demonstrated excellent mechanical properties (maximum tensile strength of 25.93 MPa and young modulus of 480 MPa) and a low coefficient of friction (COF∼ 0.07) while achieving high wear resistance (wear rate in the order of 1m ). The study shows that the improvement in mechanical properties results in a corresponding improvement in tribological properties. The antibacterial tests revealed that the hybrid composite material exhibited resistance to E. coli and S. aureus bacteria. The findings of this study suggest that the HDPE-30%HAP-10% Ti composite is a promising material for use in biomedical applications due to its excellent biocompatibility and desirable mechanical and tribological properties. The study demonstrates the potential of reinforced hybrid composite materials in overcoming the disadvantages of monolithic and hybrid micro-composites and highlights the importance of investigating the microstructural, tribological, and mechanical strength characteristics of composite materials for biomedical applications.

Crude bricks are composite materials manufactured with sediments and natural fibers. Natural fibers are waste materials and used in construction materials for reinforcement. Their reuse in manufacturing reinforced crude bricks is eco-friendly and improves mechanical and thermal characteristics of crude bricks. Factors such as type of fibers, percentage of fibers, length of fibers and distribution of fibers inside the bricks have significant effect on mechanical, physical and thermal properties of biobased composite materials. It can be observed by tests such as indirect tensile strength, compressive strength for mechanical characteristics, density, shrinkage, color for physical properties, thermal conductivity and resistivity for thermal properties, and inundation test for durability of crude bricks. In this study, mechanical and physical characteristics of crude bricks reinforced with palm oil fibers are investigated and effect of change in percentage and length of fibers is observed. Crude bricks of size 4*4*16 cm3 are manufactured with dredged sediments from Usumacinta River, Mexico and reinforced with palm oil fibers at laboratory scale. For this purpose, sediments and palm oil fibers characteristics were studied. Length of fibers used is 2cm and 3cm. Bricks manufacturing steps such as sediments fibers mixing, moulding, compaction and drying are elaborated. Dynamic compaction is opted for compaction of crude bricks due to energy control. Indirect tensile strength and compressive strength tests are conducted to identify the mechanical characteristics of crude bricks. Physical properties of bricks are studied through density and shrinkage. Durability of crude bricks is observed with inundation test. Thermal properties are studied with thermal conductivity and resistivity test. Distribution and orientation of fibers and fibers counting are done to observe the homogeneity of fibers inside the crude bricks. Finally, comparison between the mechanical characteristics of crude bricks manufactured with 2cm and 3cm length with control specimen was made.

Agricultural waste is one of the major concerns in present society. The present work investigates the possibility of agricultural waste materials, Crotalaria and Borassus short fibers, as hybrid reinforcement in composite materials. The study examines a novel approach by investigating the combined effect of hybridization and random fiber orientation on the mechanical and water absorption properties of untreated Crotalaria Juncea (CJ) and Borassus Flabellifier (BF) fibre reinforced hybrid polyester resin composites. The outcomes provide awareness into the possibility of utilizing agricultural waste for sustainable and eco-friendly hybrid composite materials. Hybrid composites were developed through the hand lay-up method, incorporating two distinct short fibres. These composites were then evaluated for their mechanical properties and water absorption characteristics, following the guidelines set by ASTM standards. A hybrid composite (HC20CJ30BF) composed of 20g of CJ and 30g of BF exhibits the highest tensile strength of 22.59 MPa, which is a notable improvement of 96.26% compared to single reinforced composites. An enhanced flexural strength of 47.46% was achieved, surpassing the performance of the single reinforced composite materials. The water absorption resistance of the hybrid composite, HC20CJ30BF, is demonstrated by its least absorption rate of 1.65% after 24 h of immersion. The fractographic analysis exposed fiber pull-out as well as rough surfaces in tensile tests, and fiber bending with matrix cracks during flexural loads, emphasizing the significant role of fiber orientation in enhancing composite performance. Such work provides valuable insight into the fabrication of highly efficient and durable hybrid composite materials employing natural fibers.

Presently, several different kinds of polymer composite materials of varying properties have been developed and these composite materials play a vital role in construction and automotive industries. Polymer composites are normally preferred owing to some of their unique properties such as light weight, low cost, good surface finishes, more durability, and non-corrosiveness. But it is a challenge to environmental sustainability, therefore researchers are emphasizing on development of new modified biodegradable polymer composite materials. The biopolymer matrix reinforced by synthetic fibers is a viable alternative, which exhibits adequate mechanical properties and biodegradability. Although various advanced and improved composite materials are developed by using synthetic fibers, natural fibers, and nanoparticles, the use of synthetic fibers as reinforcing material is cost effective and shows improved performance. Among the various kinds of synthetic fibers, normally glass fibers (GF) in the form of short fiber are the most widely used reinforcing material, which is cost effective, provides good impact resistance, stiffness, strength, thermal stability, and chemical resistance. For requirement of high stiffness of the composite material, carbon fibers (CF) are more suitable than GF. Some other synthetic fibers such as aramid (AF), polypropylene fibers (PP-F), polyacrylonitrile fiber (PAN-F), basalt (BF), and polyethylene terephthalate fiber (PET-F) are some cases used as reinforcing material for synthesis of composites. The composite reinforced with synthetic fibers are used as a highly suitable material for manufacturing of various components in cars, space vehicles and railways. Recently some new hybrid composite materials are developed by using both natural and synthetic fibers as reinforcing material, which exhibits dynamic thermal, mechanical properties and potentially suitable from automobile to construction industry. Recently, numerous new biomaterial composite has been developed by using biopolymer as matrix with reinforcement of various kinds of synthetic fibers, which are used as good implant material for tissue engineering applications.

Composites made with natural fibers are being increasingly studied to substitute fiber-reinforced plastics (FRPs) of synthetic carbon and glass fibers. Hybridization, or combining natural and synthetic fibers in a single composite, successfully enhances natural fiber-reinforced composites’ overall performance, including their strength, stiffness, and durability. The present research investigates the impact of hybridization on the durability of natural fiber composites. Jute fiber is hydrophilic in nature, which can affect its durability or service life when exposed to water. Therefore, this study aims to understand the impact of the hybridization of jute (J) and carbon (C) fibers on the water uptake, tensile properties, flexural properties, and viscoelastic properties of hybrid laminates. Furthermore, the fracture morphology of the specimens was also investigated. Two hybrid composites JCCJ and CJJC made with jute (J) and carbon (C) fibers were fabricated using epoxy resin (TS-A) through a vacuum-assisted resin infusion (VARI) technique. The results show that the hybridization of carbon and jute fiber improves the flexural and tensile properties of the laminates. The hybrid composite CJJC and JCCJ exhibited tensile strengths of 377.1 MPa and 408.6 MPa, and flexural strengths of 405.4 MPa and 158.5 MPa, respectively. The results also revealed a reduction in water absorption, with JJJJ exhibiting the highest equilibrium moisture content at 9.3, while JCCJ and CJJC show lower values at 6.55 and 5.69, respectively. Overall, the CJJC laminate showed better damping and mechanical properties among the two hybrids after 4 months of aging in water.

Hybrid carbon and glass fibre composites

This study uses laminated composite materials made of hybrid glass and carbon fibers to determine the mechanical characteristics of the foot. Tensile, bending, and fatigue of composite material were evaluated and applied to the ANSYS model. The volume fraction for carbon and glass fibers was 22.5% and 10.04%, respectively. The mechanical property results: σy = 40 MPa, σult = 150 MPa, and E = 1.2 GPa. The patient is a 30-year-old male with a left amputation side, 1.60 meters tall, and weighs 74 kg. The analysis was carried out for the two scenarios (toe-off and heel contact) as boundary conditions. The overall deformation, equivalent stresses, and foot safety factor have been calculated using ANSYS17.2 software. In the end, it appears that the foot is secure based on equivalent stress calculations and the Von-Mises hypothesis. The computed safety factor for the foot is constructed of a chosen composite material with the subsequent layers. When the heel (stance phase) is fixed at 1.3449, and the metatarsal (toe off) is fixed at 1.259, the safety factor for a force of 860 N is reached. The foot is secure, according to the Von-Mises hypothesis.

Natural fiber reinforced composite materials are most increasingly used as sustainable structures in engineering industries due to their vast availability and eco-friendly nature. In this regard, an emphasis is given in the present work to the use of natural fiber in structural composite material in place of synthetic fibers for structural applications. In the present study, the mechanical properties and free vibration characteristics of a pure green composite laminate were experimentally evaluated. For complete understanding of the behaviour of green composite material, a second laminate is prepared using synthetic resin. Two types of composite laminates were fabricated by hand layup method. In the pure green laminate, natural flax fiber is embedded in cashew nut shell liquid (CNSL) resin and for the second laminate epoxy resin is used as matrix. The flax fiber is preferred due to its high mechanical strength among all the natural fibers. Alkaline treatment is done for the natural flax fiber before fabrication to remove impurities and also improve the surface adhesion. Both the laminates were tested for mechanical properties and free vibration characteristics according to ASTM standards. The experimentally evaluated tensile, flexural properties and modal frequency values of two types of laminates are reported and discussed.

A pylon tube is an important component of the transtibial prosthesis which bears the weight of the patient. It influences the gait performance and comfort of the patient, where its flexibility can dictate the ground reaction forces associated with walking and step-down. Buckling is the common mode of failure. In this study, the buckling propensity of prosthetic pylon tube materials such as polypropylene (PP), titanium alloy (Ti–6Al–4V) and carbon fiber reinforced composite (CFRC) were evaluated using 3D simulation by finite element method analysis. A novel carbon fiber-pineapple fiber reinforced composite (CPFRC) material was also included as an alternative to CFRC. Parametric changes showed that the critical buckling load value for all materials increased with increasing diameter and thickness. A 120% increase in critical load was observed for both titanium alloy and CPFRC when the pylon tube length was decreased by half. Considering the price and its mechanical properties, the carbon fiber-pineapple fiber reinforced composite material can therefore be an alternative for titanium alloy or carbon fiber-based prosthetic pylon.