Comparison of In-Plane Mechanical Performances of Masonry Walls Strengthened with Different Mortar Coatings Reinforced with Glass or Carbon Fiber Composite Meshes

2017 ◽  
Vol 747 ◽  
pp. 289-297 ◽  
Author(s):  
Natalino Gattesco ◽  
Ingrid Boem
Keyword(s):  
Carbon Fibers ◽  
Coating Layer ◽  
Fiber Composite ◽  
Shear Stiffness ◽  
Masonry Walls ◽  
Compression Tests ◽  
Carbon Fiber Composite ◽  
Diagonal Compression ◽  
Mechanical Performances ◽  
Compression Resistance

The results of some diagonal compression tests performed on solid brick masonry samples (1160x1160x250 mm3) to evaluate and compare the effectiveness of different shear reinforcement techniques for existing masonry based of the application, on both sides of the wall, of a mortar coating layer reinforced with fiber composite meshes are presented and discussed in the paper. In particular, 30 mm and 10 mm thick mortar coatings, made of three different mortar types and reinforced by means of both glass and carbon-fibers composite meshes were considered. Significant resistance increases (about 110%) were attained in respect to plain masonry; moreover, it emerged that the meshes are able to prevent the masonry brittle collapse, absorbing tensile stresses in the cracked areas. By maintaining constant the coating thickness, better mortar characteristics determined an increase of the resistance increment ratio but a more rapid decrease of resistance after peak. Similar performances were attained by samples characterized by approximately constant values of shear stiffness and diagonal compression resistance. The differences attributable to the different type of meshes resulted minimal, due to the similar reinforcement percentage.

scholarly journals Lightweight Cellulose/Carbon Fiber Composite Foam for Electromagnetic Interference (EMI) Shielding

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1319 ◽  
Author(s):  
Ran Li ◽  
Huiping Lin ◽  
Piao Lan ◽  
Jie Gao ◽  
Yan Huang ◽  
...  
Keyword(s):  
Carbon Fiber ◽  
Carbon Fibers ◽  
Electromagnetic Interference ◽  
Fiber Composite ◽  
Carbon Fiber Composites ◽  
Shielding Effectiveness ◽  
Electromagnetic Interference Shielding ◽  
Carbon Fiber Composite ◽  
Foaming Process ◽  
Long Carbon Fibers

Lightweight electromagnetic interference shielding cellulose foam/carbon fiber composites were prepared by blending cellulose foam solution with carbon fibers and then freeze drying. Two kinds of carbon fiber (diameter of 7 μm) with different lengths were used, short carbon fibers (SCF, L/D = 100) and long carbon fibers (LCF, L/D = 300). It was observed that SCFs and LCFs built efficient network structures during the foaming process. Furthermore, the foaming process significantly increased the specific electromagnetic interference shielding effectiveness from 10 to 60 dB. In addition, cellulose/carbon fiber composite foams possessed good mechanical properties and low thermal conductivity of 0.021–0.046 W/(m·K).

scholarly journals The Effect of Transversal Connection in the in-Plane Response of Double-Leaf Brick Masonry Walls

2021 ◽  
Author(s):  
Lorenzo Scandolo ◽  
Stefano Podestà
Keyword(s):  
Structural Safety ◽  
Masonry Walls ◽  
Masonry Building ◽  
Mechanical Parameters ◽  
Compression Tests ◽  
Knowledge Process ◽  
Diagonal Compression ◽  
Set Up ◽  
Definition Of ◽  
Simplified Mechanical Model

Abstract The evaluation of structural safety derives from the knowledge of material properties. In case of existent masonry building, the definition of reliable mechanical parameters could be a very difficult task to be achieved. For this reason, an estimation of these values is useful, for example it is the first phase of the knowledge process, for simplified mechanical model or when NTD test is the only possibility.The transversal connection in masonry panels is a technological detail that affects the static and seismic behavior and could significantly increase the strength of the element.In this paper the effect of transversal connection in double-leaf brickwork masonry panels is evaluated by diagonal compression tests. To achieve this goal, a new set-up was designed to load each leaf independently.The results have shown an increment of about 20% in strength if transversal connection is present. If the leaves have very different mechanical parameters, the tests highlight an unexpected behavior.

scholarly journals Shape-morphing carbon fiber composite using electrochemical actuation

2020 ◽  
Vol 117 (14) ◽  
pp. 7658-7664 ◽  
Author(s):  
Wilhelm Johannisson ◽  
Ross Harnden ◽  
Dan Zenkert ◽  
Göran Lindbergh
Keyword(s):  
Solid State ◽  
Carbon Fibers ◽  
Fiber Composite ◽  
Lithium Ion ◽  
Proof Of Concept ◽  
Carbon Fiber Composite ◽  
Shape Morphing ◽  
Commercial Carbon ◽  
Structural Battery ◽  
Shape Changes

Structures that are capable of changing shape can increase efficiency in many applications, but are often heavy and maintenance intensive. To reduce the mass and mechanical complexity solid-state morphing materials are desirable but are typically nonstructural and problematic to control. Here we present an electrically controlled solid-state morphing composite material that is lightweight and has a stiffness higher than aluminum. It is capable of producing large deformations and holding them with no additional power, albeit at low rates. The material is manufactured from commercial carbon fibers and a structural battery electrolyte, and uses lithium-ion insertion to produce shape changes at low voltages. A proof-of-concept material in a cantilever setup is used to show morphing, and analytical modeling shows good correlation with experimental observations. The concept presented shows considerable promise and paves the way for stiff, solid-state morphing materials.

FRCM Strengthened Masonry Panels: The Role of Mechanical Anchorages and Symmetric Layouts

2017 ◽  
Vol 747 ◽  
pp. 334-341 ◽  
Author(s):  
Francesca Ferretti ◽  
Andrea Incerti ◽  
Barbara Ferracuti ◽  
Claudio Mazzotti
Keyword(s):  
Masonry Walls ◽  
Fiber Reinforced ◽  
Compression Tests ◽  
Fiber Reinforced Composite ◽  
Single Leaf ◽  
Reinforced Composite ◽  
Experimental Campaign ◽  
Diagonal Compression ◽  
Strength And Ductility

The use of fiber reinforced composite materials for the retrofitting of existing masonry buildings is investigated in this paper. Indeed, they represent a great alternative to traditional strengthening techniques for the improvement of the seismic performance of masonry walls. Focusing on the in-plane behavior of masonry, an experimental campaign is here presented with the objective of studying the efficiency of different strengthening solutions. Diagonal compression tests were conducted on single-leaf masonry panels reinforced with Fiber Reinforced Cementitious Matrix (FRCM) using different fibers typologies and layouts. Glass or carbon fiber grids embedded in a lime-based mortar matrix were applied on one or both sides of masonry panels, with or without mechanical anchorages. The comparison of the different strengthening techniques is analyzed in terms of failure mode, strength and ductility. The results are then discussed considering the provisions and design formula proposed for FRP strengthening by the Italian CNR Guidelines.

Layup Analyzing of a Carbon/Glass Hybrid Composite Wind Turbine Blade Using Finite Element Analysis

2011 ◽  
Vol 87 ◽  
pp. 49-54 ◽  
Author(s):  
Hai Chen Lin
Keyword(s):  
Finite Element ◽  
Carbon Fiber ◽  
Wind Turbine ◽  
Glass Fiber ◽  
Turbine Blade ◽  
Carbon Fibers ◽  
Fiber Composite ◽  
Wind Turbine Blade ◽  
Fiber Reinforced ◽  
Carbon Fiber Composite

This thesis use AOC15/50 blade as baseline model which is a composite wind turbine blade made of glass/epoxy for a horizontal axis wind turbine. A finite element modeling of composite wind turbine blade was created using the SHELL element of ANSYS. Then we study how to use the carbon fiber material replaces the glass fiber to make the hybrid blade, and find a suitable layup to improve the performance of the blade. The hybrid blade was made through introducing carbon fibers. Different models, with introducing different number of carbon fibers, 75% carbon fibers replace unidirectional glass fibers in spar cap of blade model which can achieve best structure performance. The wind turbine blades are often fabricated by hand using multiple of glass fiber-reinforced polyester resin or glass fiber-reinforced epoxy resin. As commercial machines get bigger, this could not to meet the demands. The advantages of carbon fiber composite materials are used by blade producer. Studies show that carbon fiber has high strength-to-weight ratio and resistance fatigue properties. Carbon fiber is mixed with epoxy resin to make into carbon fiber-reinforced polymer. Carbon fiber-reinforced polymer is the one of best blade materials for resistance bad weather. The stiffness of carbon fiber composite is 2 or 3 times higher than glass fiber composite [1], but the cost of carbon fiber composite is 10 times higher than glass fiber composite. If all of wind turbine blades are made of carbon fiber composite, it will be very expensive. Therefore carbon/glass fiber hybrid composite blade has become a research emphasis in the field of blade materials. This paper gives an example of finite element modeling composite wind turbine blade in ANSYS by means of the medium-length blade of AOC 15/50 horizontal axis wind turbine. This model can be directly used in dynamics analysis and does not need to be imported from the CAD software into finite element program. This finite element modeling of composite wind turbine blade was created using the SHELL element of ANSYS. Then we study how to use the carbon fiber material replaces the glass fiber to make the hybrid blade, and find a suitable lay-up to improve the performance of the blade.

Destructive Tests for the Determination of Masonry Performance

2009 ◽  
Vol 417-418 ◽  
pp. 753-756
Author(s):  
Lucio Nobile ◽  
Cristina Gentilini ◽  
Veronica Bartolomeo ◽  
Mario Bonagura
Keyword(s):  
Mechanical Properties ◽  
Experimental Research ◽  
State Of The Art ◽  
The State ◽  
Masonry Walls ◽  
Compression Tests ◽  
Diagonal Compression

Several masonry panels are studied by means of destructive tests such as compressive, diagonal compression and shear-compression tests. The experimental research allows to characterize the mechanical properties of masonry walls in order to assess the masonry performance. Moreover, a brief recall of the most important experimental progress is presented in order to understand the state of the art of the research in the field of destructive tests.

Manufacturing Technique and Property Evaluation of Polypropylene/ Carbon Fiber Composite Braids

2011 ◽  
Vol 239-242 ◽  
pp. 141-144
Author(s):  
Jia Horng Lin ◽  
Jin Mao Chen ◽  
Ching Wen Lin ◽  
Wen Hao Hsing ◽  
Yu Chia Hsu ◽  
...  
Keyword(s):  
Tensile Strength ◽  
Carbon Fiber ◽  
Thermal Treatment ◽  
Tensile Properties ◽  
Carbon Fibers ◽  
Fiber Composite ◽  
Carbon Fiber Composite ◽  
Manufacturing Technique ◽  
Property Evaluation ◽  
Different Levels

In this study, carbon fibers (CF) were braided with polypropylene (PP) fibers on a 16-spindle braid machine, forming the PP/ CF composite braids. The composite braids with different levels of strength could be obtained by changing the speed of the yarn turntable and volume gauze. The composite braids with optimum tensile strength then received the thermal treatment, which melted the PP fibers to wrap the CF more tightly, stabilizing the structure of the composite braids. According to CNS 11623 (Tensile Properties of Geogrids by the Single), the composite braids were thermal-treated at 170 °C, 180 °C and 190 °C for1 min, 2 min and 3 min, determing the influence of thermal temperature and duration on the tensile strength of PP/ CF composite braids.

Study on Preparation Method and Energy-Absorbing Characteristics of Carbon Fiber Composite Energy Absorber

2013 ◽  
Vol 442 ◽  
pp. 98-103
Author(s):  
Chang Jie Luo ◽  
Hai Liang Zhang ◽  
Wen Ze Yu ◽  
Kai He ◽  
Ru Xu Du
Keyword(s):  
Carbon Fiber ◽  
Preparation Method ◽  
Fiber Composite ◽  
Compression Tests ◽  
Carbon Fiber Composite ◽  
Energy Absorber ◽  
Static Compression ◽  
Advantages And Disadvantages ◽  
Energy Absorbing ◽  
Composite Energy

By analyzing advantages and disadvantages of the existing energy absorbers, carbon fiber composite and regular hexagon honeycomb structure were chosen as material and topological structure respectively to make a big-bearing, lightweight energy absorber. Preparation method of carbon fiber composite honeycomb energy absorber was studied, which was applied to manufacture some specimens,and it is feasible because of the specimens good consistency and regularity. Quasi-static compression tests of the specimens were carried out, and then the related parameters of energy-absorbing characteristics were calculated. The results show that the carbon fiber composite honeycomb energy absorber has excellent energy-absorbing characteristics.

scholarly journals In-plane shear modulus of cross-laminated timber by diagonal compression test

BioResources ◽  
2019 ◽  
Vol 14 (3) ◽  
pp. 5559-5572 ◽  
Author(s):  
Sven Berg ◽  
Jonas Turesson ◽  
Mats Ekevad ◽  
Anders Björnfot
Keyword(s):  
Shear Modulus ◽  
Compression Test ◽  
Pure Shear ◽  
Shear Stiffness ◽  
Least Square ◽  
Compression Tests ◽  
Plane Shear ◽  
Cross Laminated Timber ◽  
Fe Simulations ◽  
Diagonal Compression

Cross-laminated timber (CLT) is an engineered wood material that is used in the construction industry, e.g., for floors, walls, and beams. In cases where CLT-elements are used as shear walls, the in-plane-stiffness is an important property. For non-edge glued CLT, in-plane shear stiffness is lower than for edge-glued CLT. To evaluate the non-edge glued CLT panel’s in-plane shear modulus, the diagonal compression test and finite element (FE) simulation was used. FE-models with both isotropic and orthotropic material models were used to calculate the shear stiffness. The FE models using pure shear loads were used as a reference to determine the correct value of the shear modulus. To verify the FE simulations, diagonal compression tests were conducted on 30 CLT samples. A calibration formula was derived using the least square method for calculation of shear modulus. The formula gave accurate results. The results showed that FE simulations can reproduce the same shear stiffness as tests of non-edge glued 3-layer and 5-layer CLT panels.

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