SEMINÁRIO INTERNACIONAL EM MATERIAIS COMPÓSITOS

(13/Nov/2019)

 

13:30 h: OPENING

Dr. SANDRO C. AMICO

13:45 h: POLYMER COMPOSITES FOR AERO-ENGINE APPLICATIONS

Dr. PATRIK FERNBERG

Abstract: The trend in aero-engine design 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 studies of matrix rheology, preform permeability, residual stress formation as well as particle filtration aspects will be addressed. 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.

14:35 h: MICRODAMAGE IN PLIES OF LAMINATES: EVOLUTION AND EFFECT ON MACRO-PROPERTIES

Dr. JANIS VARNA

Abstract: Intralaminar cracking in plies and bundles with off-axis orientation is the first mode of damage in quasi-static as well as in cyclic loading, causing stiffness degradation and initiating delaminations and fiber breaks in adjacent plies. Two groups of stiffness simulation approaches (based a) on average stress between cracks and; b) on average opening and sliding displacements (COD and CSD) of cracks) are analyzed, showing their equivalence. As a simple alternative, the effective stiffness concept of the damaged ply is revisited, showing that the damage state dependent effective properties functions obtained in FEM simulations, when used in the framework of the Classical Laminate Theory, give excellent predictions of thermo-elastic constants. The state of the art in damage initiation analysis is given, focusing on fiber/matrix debonds and their interactions within the composite ply and with the free surface of the ply or with the interface with stiff adjacent layers. Stress based and released energy based propagation scenarios of intralaminar cracks are discussed. Applications in fatigue behavior are discussed presenting simple and efficient methodology for parameter determination to be used in Monte Carlo simulations of damage evolution. Examples are given for laminates, NCF and woven composites.

15:25 h: COFFEE-BREAK

15:50 h: VARIABLE-AXIAL FIBER STRUCTURES: THE FUTURE OF AN EXTREME LIGHTWEIGHT DESIGN?

Dr. AXEL SPICKENHEUER

Abstract: 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. Several examples of manufacturing techniques suited for a variable-axial composite manufacturing will be explained and compared to each other. 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.

16:40 h: IMPROVING THE MECHANICAL RESPONSE OF COMPOSITE STRUCTURES WITH VARIABLE-AXIAL FIBER LAYOUTS

Dr. JOSÉ HUMBERTO S. ALMEIDA JUNIOR

Abstract: Fiber steering is an outstanding capability for producing composite structures with spatially tailored properties. Conventional tailoring of multiaxial laminates is achieved by varying the fiber orientation through-thickness of a laminate, and the thickness of particular layers. Recent advancements on advanced manufacturing techniques have led to the possibility of spatially steering fibers in the plane of a layer, which significantly increases the design space, and hence providing more tailoring options to design structures with the desired performance. Fiber steering capabilities may, indeed, tailor a particular required property placing fibers by varying fiber orientation within a layer, generating variable-axial (VA) composites, which is also known as variable-stiffness and variable angle-tow composites. This presentation covers three examples in which the mechanical performance of composite structures is enhanced: i) composite shells under axial compression for enhanced buckling behavior; ii) composite brake booster for improved stiffness; and iii) open-hole tensile specimen for decreased stress concentrations around holes.

17:45 h: CLOSING

 

INSCRIÇÕES GRATUITAS

Enviar nome completo e Instituição para gcomp.seminario@gmail.com

 

Data:  13/Novembro/2019

Local: Anfiteatro do PPGE3M/UFRGS - Av. Bento Gonçalves, 9500.

Campus do Vale - Setor 4 - Prédio 43426

Para ver um mapa com a localização do PPGE3M,  clique aqui!

 

Promoção: