I Ciclo de Seminários Internacionais em Materiais Compósitos


Entre os meses setembro a dezembro de 2020 a ABPOl-Sul foi realizado o I Ciclo de Seminários Internacionais em Materiais Compósitos.

O conteúdo foi apresentado de forma on-line e gratuito. 

Maiores  informações acesse: www.facebook.com/abpolsul

Todos os seminários foram gravados e os links de acesso aos conteúdos  estão na programação abaixo.


Seminário 7

Realizado em: 09 de dezembro de 2020

Horário: Das 16h às 17h30 (Horário de Brasília)

Convidado: M.Sc. Fernando Cunha (Fibrenamics at University of Minho, Portugal)

Título: Potential of Natural Fibers in Reinforcing Composite Materials

Resumo: The use of natural fibrous materials has gained large interest of application in various sectors in order to find solutions to replace the use of conventional materials. Natural fibers also allow the weight reduction of the final composite materials, due to their lower density, in comparison to synthetic fibres. The replacement of synthetic fibres by natural ones allows lower fuel consumption, which is an important factor for environmental sustainability, due to reduction of greenhouse gases emission. Also, the natural fibrous materials are also biodegradable and recyclable, when used with thermoplastic matrices, characteristics which are equally important for sustainability. Besides these advantages, low cost and lower health hazards, comparing to synthetic fibres, are also to be considered. However, the combination of natural fibres with polymeric materials has some constraints related to the compatibility between both materials. Vegetal natural fibres are composed mainly by cellulose and hemicellulose, which are hydrophilic, and lignin on the surface, which is hydrophobic. This causes poor wettability of the natural fibres by polymers and, consequently, weak compatibility and adhesion at the interface between both materials. In this context, surface treatments on these materials for partial extraction of lignin become important to improve the compatibility with polymeric materials. depending of the applied surface treatment and its concentration, different mechanical properties can be modified. In this context, an understanding of what occurs in the morphological structure is fundamental.


Seminário 6

Realizado em: 25 de novembro de 2020

Horário: Das 16h às 17h30 (Horário de Brasília)

Convidado: Dr. Saullo G. P. Castro (Delft University of Technology, The Netherlands) and Dr. José Humberto S. Almeida Jr. (Aalto University, Finland)

Título: Variable Angle Tow Designs for Lightweight Fiber-Reinforced Structures

Resumo: An effective way to improve the stiffness and strength of composite structures aiming lightweight performance is by steering the fibers following a pre-defined path. Recent advancements on manufacturing techniques have enabled this possibility, thus producing variable-angle tow (VAT) laminates and significantly increasing the design space available to engineers. Automated Fiber Placement (AFP), Continuous Tow Steering (CTS) and Tailored Fiber Placement are the most disseminated and suitable manufacturing processes available to produce such tow-steered trajectories. Nonetheless, TFP essentially generates bi-dimensional structures; No curved-surfaces have been manufactured so far by CTS; AFP is, however, suitable to produce cylinders, but at a relatively low speed. In this direction, we have recently (2020) proved, for the first time, that filament winding (FW) is also a strong candidate to produce such extremely lightweight VAT cylinders for aerospace and aeronautical applications. In this presentation, we will show several examples on how buckling, stiffness, and strength of composite structures can be enhanced by employing VAT fiber configurations. We will show optimization, modeling, and experimental methods that best describe and improve the mechanical behavior of such VAT structures.


Seminário 5

Realizado em: 11 de novembro de 2020

Horário: Das 16h às 17h30 (Horário de Brasília)

Convidado: Prof. Dr. Erik Thostenson  (University of Delaware, USA)

Título: Multifunctional Nanostructured Composites: Case studies in Applications in Smart Garments and Structural Health Monitoring

Resumo: This presentation highlights recent research in processing, characterization and modeling of electrically conductive carbon nanotube-based composite materials. Because carbon nanotubes have diameters three orders of magnitude smaller than traditional advanced fibers there is unique opportunity to create multi-scale hybrid composite systems where reinforcement scales are combined. Our recent research has developed a highly efficient and industrially scalable electrophoretic deposition technique for nanoscale hybridization. We have demonstrated that conducting carbon nanotube networks can be utilized as highly sensitive sensors. The potential applications of these novel sensors will be discussed and recent research on utilizing these sensors for structural health monitoring of bridges and the development of smart garments for physical rehabilitation will be highlighted. A startup company, MCET Technologies, has been founded to accelerate commercialization of these discoveries.


Seminário 4

Realizado em: 28 de outubro de 2020

Horário: Das 16h às 17h30 (Horário de Brasília)

Convidado: Dr. Christina Scheffler  (IPF Dresden, Germany)

Título: Surfaces and Interphases in Fiber-Reinforced Composites - Small But Powerful

Resumo: When reinforcing fibers and matrix meet during the production of fiber reinforced composites, a contact zone is formed whose chemical, physical and mechanical properties differ from those of the fiber and matrix material. This contact zone is called the interphase and plays an essential role with regards to the mechanical properties of fiber-reinforced composites. Although done for many years, it is still challenging to improve this composites key property. In general, sizing or coatings are used to modify the surfaces of reinforcing fibers. In addition to fiber-matrix adhesion and composite performance, however, the coatings must ensure further application-relevant factors such as improved wetting, corrosion resistance and textile processability. During the last years the focus was additionally also set on conductivity for sensoring or structuring by nano particles. The glass fiber and online hybrid yarn spinning devices set up at the IPF have been enabling research for application-oriented surface modification for many years. In the course of the presentation various examples will be shown. Furthermore, the equipment available at the IPF for micromechanical characterization of the fiber-matrix interaction by means of single fiber pull-out test will be presented.


Seminário 3

Realizado em: 15 de outubro de 2020

Horário: Das 16h às 17h30 (Horário de Brasília)

Convidado: Prof. Dr. Patrik Fernberg (Luleå University of Technology, Sweden)

Título: Polymer Composites for Aeronautical and Aero-engine Applications

Resumo: It is well established that introduction of fiber composites technologies have played an important role for improving overall fuel economy of recent aircraft generations. While fuel consumption reductions in aircrafts have been substantial they are not sufficient to make aeronautics industry climate neutral by 2050. The talk will introduce and discuss  some of the important generic challenges for future composite research. A more detailed discussion on some potentials with composites in aero-engine. The trend in aero-engine development is that engines are increasing in diameter and this creates strong  incentives to use carbon fibre composites in areas where temperatures are not too high. In the talk, some selected previous R&D efforts dedicated for the development of materials technologies particularly for aero-engines will be presented. RTM-manufacturing related aspects such as matrix rheology, curing behavior, preform permeability and residual stress will be addressed. Other application driven key challenges such as thermo-oxidative stability and fire resistance will be discussed.  Both traditional material systems based on epoxy resins as well as thermosetting polyimides will be discussed alongside with a discussion on challenges addressed in current research.


Seminário 2

Realizado em: 30 de Setembro

Horário: Das 16h às 17h30 (Horário de Brasília)

Convidado: Prof. Dr. Andrea Manes (Politecnico di Milano, Itália)

Título: Ballistic Impact on Composite Materials: Experimental and Numerical Analysis

Resumo: Ballistic impact on composite materials have been widely investigated in the last decades due to fiber-reinforced composites are a preferred choice for the manufacturing of ballistic shields.  Enhance lightness whilst preserving protection capabilities is a key feature for transportations where lightweight solutions are preferred to reduce fuel consumption or increase payload. For this purpose, experimental tests are vital, especially for certification purposes. Ballistic impact results are affected by many parameters, and there is a large number of materials combinations and phenomena involved. Thus, finding an optimal solution based mainly on experimental tests is not feasible, and several predictive modelling approaches have been recently developed. Numerical modelling allows a wider description of the physics involved during impact phenomena, but their use is not straightforward and requires greater efforts in order to get reliable results. Aim of this seminar is to provide a brief overview of the expertise of POLIMI Research Team on the topic of investigating ballistic impact behavior of composite material by means of a mixed approach based on experimental tests (mainly carried out using bullet impactors) and numerical high-fidelity models.


Seminário 1 

Realizado em: 16 de Setembro

Horário: Das 16h às 17h30 (Horário de Brasília)

Convidado:  Dr. Axel Spickenheuer (IPF Dresden, Alemanha)

Título: Variable-axial Fiber Structures: The Future of an Extreme Lightweight Design?

Resumo: In lightweight fiber-reinforced composite structures, their intrinsic anisotropy needs to be addressed in order to fully take advantage their ability to withstand loading with lower safety factors. Stress adaptive curvilinear, also called variable-axial, fibers paths, lead to significantly increased strength- and stiffness-to-weight ratios when compared, for instance, to classical multiaxial composite laminate. For the production of composite parts based on variable-axial fiber patterns, the Tailored Fiber Placement (TFP) technology was developed at the IPF Dresden in the early 1990s. Since TFP is a technology with many degrees of freedom, generating optimized fiber layouts is particularly challenging. Within the lecture the state of the art in extreme lightweight design based on a variable-axial fiber architecture will be presented. Additionally, a short historical and technical overview of the design of variable-axial composite will be given and present state of the art modelling approached will be explained. Finally, several academic and actually industry related composite parts made by TFP will be presented.




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