Examinando por Autor "Moure, M.M."

Mostrando 1 - 5 de 5

Drilling characteristics and properties analysis of fiber reinforced polymer composites: A comprehensive review
(Elsevier, 2023-03) Jagadeesh, P.; Mavinkere Rangappa, Sanjay; Suyambulingam, I.; Siengchin, S.; Puttegowda, M.; Binoj, J.S.; Gorbatyuk, S.; Khan, A.; Doddamani, M.; Fiore, V.; Moure, M.M.
Fiber-reinforced polymer (FRP) composites play a vital role in the production of structural and semi-structural components for engineering applications. The drilling process is a commonly employed machining process for FRP composites to join the FRP structural elements. Usually, the FRP composites possess a heterogeneous nature because of their multi-layered structure, hybridization, and the presence of multi-phase materials. Hence, common problems like delaminations, fuzzing, buckling, cracking, matrix and fiber burning occur during the drilling operations. These problems cause dimensional inaccuracy, poor surface finish, and tool wear and reduce the mechanical strength of the composites. The optimum drilling parameters (drill geometry, speed, feed, and depth of cut) selection for the specific materials is good to achieve effective drilling performance and better surface quality of the holes. Yet, little study has been done on how all of these factors affect the size of the drilled hole. The majority of drilling studies on FRPCs in the past have focused on how to improve the hole quality by maximizing processing conditions, and there has been little discussion on the correlation between drilling conditions, physical properties, and production techniques. This is what motivated to review the characteristics and properties analysis of FRP composites. As a consequence of this research, it is anticipated that scientists and researchers would place a greater emphasis on the drilling characteristic of the workpieces made from FRPCs than on other attributes. This review clearly presents an overview of FRP composites drilling that had progressed from 2000 to 2021. The analysis of different drilling conditions and parameters like thrust force, drill geometry, temperature, speed, and feed also includes the post-drilling analysis through delaminations, thermal damage, and surface roughness. Furthermore, the recent developments in carbon, glass, and natural fiber reinforced polymer composites are studied with both conventional and nonconventional drilling techniques. Based on the above studies, some future challenges and conclusions are drawn from this review.
Mechanical Characterization of Synthetic Gels for Creation of Surrogate Hands Subjected to Low-Velocity Impacts
(MDPI, 2022-09-02) Sosa, E.M.; Moure, M.M.
The development of human body simulators that can be used as surrogates for testing protective devices and measures requires selecting synthetic materials with mechanical properties closely representative of the human tissues under consideration. For impact tests, gelatinous materials are often used to represent the soft tissues as a whole without distinguishing layers such as skin, fat, or muscles. This research focuses on the mechanical characterization of medical-grade synthetic gels that can be implemented to represent the soft tissues of the hand. Six grades of commercially available gels are selected for quasi-static hardness and firmness tests as well as for controlled low-velocity impact tests, which are not routinely conducted by gel manufacturers and require additional considerations such as energy level and specimen sizes relevant to the specific application. Specimens subject to impacts represent the hand thicknesses at the fingers, knuckles, and mid-metacarpal regions. Two impact test configurations are considered: one with the gel specimens including a solid insert representing a bone and one without this insert. The impact behavior of the candidate gels is evaluated by the coefficient of restitution, the energy loss percentage, and the peak reaction force at the time of impact. The resulting values are compared with similar indicators reported for experiments with cadaveric hands. Relatively softer gels, characterized by Shore OOO hardness in the range of 32.6 ± 0.9 to 34.4 ± 2.0, closely matched the impact behavior of cadaveric specimens. These results show that softer gels would be the most suitable gels to represent soft tissues in the creation of surrogate hands that can be used for extensive impact testing, thus, minimizing the need for cadaveric specimens.
Preparation and characterization of new hybrid polymer composites from Phoenix pusilla fibers/E-glass/carbon fabrics on potential engineering applications: Effect of stacking sequence
(John Wiley and Sons Inc, 2020-11) Puttegowda, M; Rangappa, S.M.; Khan, A; Al-Zahrani, S. Ahmed; Otaibi, Al Otaibi; Shivanna, P; Moure, M.M.; Siengchin, S
The use of bio-fiber-based hybrid composites in various commercial engineering applications is increasing day by day due to their biodegradability and versatile characteristics. Hence, in the present research investigation, an attempt has been made to scrutinize the mongrelizing possessions under different laminate stacking arrangement concerning Phoenix pusilla fibers (PPFs)/E-glass woven/carbon woven fabric-reinforced epoxy composite laminates through the studies of density, void fraction, and different mechanical strength behavior evaluation of five resulting diverse hybrid composite laminates. The hybrid laminates were prepared by manual hand lay-up technique. The scrutinization of physical and mechanical properties and the study of fractured surfaces specify noteworthy improvement in density, void fraction, tensile properties, flexural properties, and microhardness properties of PPFs/E-glass/carbon fabrics-reinforced hybrid epoxy composites. The overall results conferred that the composite laminates fabricated in the present study could be potentially used in medium load structural applications.
Simulation of low-energy impacts on the human hand for prediction of peak reaction forces and bone fracture
(Elsevier Ltd, 2023-11) Sosa, E.M.; Moure, M.M.
Hands of workers in extractive and heavy-duty industries are susceptible to suffering injuries of varying severity. Improved safety procedures and new technologies for production and maintenance tasks have contributed to reducing the severity of injuries. However, manual tasks with high-risk factors can still lead to hand injuries. Hand bone fractures and dislocations can be caused by relatively small objects impacting a region of the hand at velocities in the range of 1.3 to 1.6 m per second. This impact can produce significant functional, physical, and psychological consequences in those affected and result in high costs derived from medical care. This study presents the results of a finite element simulation study conducted to reproduce impacts with energies in the range of 7 to 10 Joules of an object on the dorsal region of the hand. Simulation results are compared to previous experimental results obtained from controlled impact tests performed using cadaveric hand specimens. The vertical peak reaction force (PRF) as a function of the impact position was used as a primary outcome for comparisons. Simulation results for all impact positions were within the standard deviation measured experimentally, with differences in the PRF values in the range of −5.3% to 4.9%. Bone stress analyses at the position of impacts showed the locations where the maximum principal stress exceeded the bone strength, as well as the variability in the correspondence between the stress distribution predicted by the FE models and the fracture rate distribution observed experimentally.
Sustainable recycling technologies for thermoplastic polymers and their composites: A review of the state of the art
(John Wiley and Sons Inc, 2022-09) Jagadeesh, P; Mavinkere Rangappa, Sanjay; Siengchin, Suchart; Puttegowda, Madhu; Thiagamani, S.M. Kumar; Rajeshkumar, G; Hemath Kumar, M; Oladijo, O.P.; Fiore, V; Moure, M.M.
This review article discusses the environmental and economic effects of recycling, as well as sustainable thermoplastic polymer recycling technologies. Several researchers have utilized recycled thermoplastics as matrices in the production of a variety of natural and synthetic-based composites, which is also the focus of this study. All of the industries (food and packaging, construction and building, transportation, and indoor usage) where recycled thermoplastics have a large market share (food and packaging, construction and building, transportation, and indoor usage) are covered in this review. The desirable properties of thermoplastic polymers, such as corrosion resistance, low density, and user-friendliness, have caused plastic production to surpass aluminum and other metals in use over the past 60 years. Furthermore, recycling is one of the most important measures available to mitigate these effects and is one of the most dynamic segments of the plastics industry at present. Increased landfilling and incineration of plastics have a negative impact on the ecosystem, and the continued increase in the production of virgin fossil plastic also has a negative impact on the environment. Consequently, this continuous production could lead to the depletion of fossil fuel resources, an increase in environmental emissions during processing, and eventual incineration. Increasing numbers of nations are adopting the circular economy concept in an effort to avoid all of these problems. This concept emphasizes the reuse of products and resources, as well as the recycling of materials according to the waste hierarchy, rather than their cremation or disposal in the environment.