Flexural Behavior of Hybrid Layered Composites Suitable for Automotive Structural Applications

2021 ◽  
Author(s):  
Arockia Julias A ◽  
Jeyakumar Ponniah Daniel ◽  
D Murali Manohar ◽  
Thirumurugan Muthiah ◽  
Sathish Kumar R
Keyword(s):  
Flexural Behavior ◽  
Layered Composites ◽  
Structural Applications

Investigation on Improvement of Flexural Behavior of Low-Density Cellular Concrete through Fiber Reinforcement for Non-Structural Applications

2019 ◽  
Vol 2673 (10) ◽  
pp. 641-651
Author(s):  
Arman Abdigaliyev ◽  
Jiong Hu
Keyword(s):  
Mechanical Properties ◽  
Lightweight Concrete ◽  
Construction Material ◽  
Flexural Behavior ◽  
Unit Weight ◽  
Slight Reduction ◽  
Low Density ◽  
Hybrid Fibers ◽  
Structural Applications ◽  
Cellular Concrete

During the last decades, cellular lightweight concrete (CLC), or foamed concrete, has been experiencing greater interest in geotechnical, structural, and non-structural applications. The low density and high flowability makes it a favorable construction material in relation to handling, placing, and construction costs. However, the applications of low-density cellular concrete (LDCC), the category of CLC with a unit weight less than 50 pounds per cubic foot (801 kg/m3) and generally without fine aggregates, are limited mostly to backfill applications in geotechnical engineering. The main reason lies in the brittleness of the material and low to zero resistance to flexural loads. Fiber-reinforced LDCC may be a reasonable solution to improve mechanical properties and expand the application range of the material. This study investigated the effects of adding polypropylene and hybrid fibers on physical and mechanical properties of LDCC and the feasibility of expanding LDCC utilization to non-structural applications. Results showed that although there is a slight reduction of flowability and compressive strength, the flexural behavior of LDCC can be significantly improved with the incorporation of fibers. The flexural strength and flexural toughness of LDCC was found to increase from 26.8 pounds per square inch (psi) (0.18 MPa) to 217.5 psi (1.48 MPa), and from 5.67 lb-in. (0.64 kN-mm) to 292 lb-in. (33.0 kN-mm) respectively at a 1.0% addition rate of a fibrillated polypropylene fiber selected in this study, which makes it a feasible material for non-structural applications.

scholarly journals An Efficient Approach to Describe the Fiber Effect on Mechanical Performance of Pultruded GFRP Profiles

2021 ◽  
Vol 8 ◽  
Author(s):  
Viktor Gribniak ◽  
Arvydas Rimkus ◽  
Linas Plioplys ◽  
Ieva Misiūnaitė ◽  
Mantas Garnevičius ◽  
...  
Keyword(s):  
Mechanical Performance ◽  
Mechanical Load ◽  
Computation Time ◽  
Image Correlation ◽  
Flexural Behavior ◽  
Bending Test ◽  
Experimental Program ◽  
Fe Model ◽  
Hollow Section ◽  
Structural Applications

This study focuses on the flexural behavior of pultruded glass fiber-reinforced polymer (GFRP) profiles developed for structural applications. Fiber content is a commonly accepted measure for estimating the resistance of such components, and technical datasheets describe this essential parameter. However, its direct implementation to the numerical simulations can face substantial problems because of the limitations of standard test protocols. Furthermore, the fiber mass percentage understandable for producers is unsuitable for typical software considered the volumetric reinforcement content. This manuscript exemplifies the above situation both experimentally and analytically, investigating two GFRP square hollow section (SHS) profiles available at the market. A three-point bending test determines the mechanical performance of the profiles in this experimental program; a digital image correlation system captures deformations and failure mechanisms of the SHS specimens; a standard tensile test defines the material properties. A simplified finite element (FE) model is developed based on the smeared reinforcement concept to predict the stiffness and load-bearing capacity of the profiles. An efficient balance between the prediction accuracy and computation time characterizes the developed FE approach that does not require specific descriptions of reinforcement geometry and refined meshes necessary for modeling the discrete fibers. The proposed FE approach is also used to analyze the fiber efficiency in reinforcing the polymer matrix. The efficiency is understood as the model’s ability to resist mechanical load proportional to the dry filaments’ content and experimental elastic modulus value. Scanning electron microscopy relates the composite microstructure and the mechanical performance of the selected profiles in this study.

Compression and Flexural Behavior of ECC Containing PVA Fiber

2021 ◽  
Vol 30 (1) ◽  
pp. 277-289
Author(s):  
Lee Siong Wee ◽  
Mohd Raizamzamani Md Zain ◽  
Oh Chai Lian ◽  
Nadiah Saari ◽  
Norrul Azmi Yahya
Keyword(s):  
Compressive Strength ◽  
High Performance ◽  
Failure Modes ◽  
Volume Fraction ◽  
Fiber Reinforced Concrete ◽  
Flexural Behavior ◽  
Silica Sand ◽  
Bending Test ◽  
Structural Applications ◽  
Pva Fiber

Research on Engineered Cementitious Composites (ECC) is overwhelming owing to its wide structural applications that can serve multi-functional purposes in civil and nvironmental infrastructures. Compared to other high-performance fiber reinforced concrete, ECC yields superior tensile ductility and multiple cracking behaviors when subjected to tensile loadings even with low to moderate volume of fibers. This paper presents the flexural properties of ECC made of cement, an industrial by-product, such as ground granulated blast-furnace slags (GGBS), local silica sand, polyvinyl alcohol (PVA) fiber, water, and superplasticizer (SP). Two series of ECC mixtures (ECC-G50 series and ECC-G60 series) and one control mixture were designed. The effect of two different fiber contents in volume fraction was investigated for the two series of ECC mixtures. The compression and flexural tests were conducted on ECC and control specimens after 28 days of curing. A compression test revealed that almost all ECC mixtures improved compressive strength between 20% to 30% compared to the control specimens. In addition, all ECC plate specimens demonstrated excellent strain-hardening states (i.e., displacement capacity at least ten times greater than the control specimens) and multiple fine-cracks failure modes after the three-point bending test. The increase in fiber content slightly reduced the compressive strength but enhanced the flexural behavior of the ECC-G50 series. However, this observation is not discovered in the ECC-G60 series. Outcomes of this research assist material scientists on the content of PVA fiber and GGBS used in making ECC.

Flexural Behavior of Fiberglass Polymer Composite With and Without TEOS Electrospun Nanofibers

2014 ◽  
Author(s):  
Dattaji K. Shinde ◽  
Fatima T. White ◽  
Ajit D. Kelkar
Keyword(s):  
Composite Laminates ◽  
Impact Resistance ◽  
Electrospun Nanofibers ◽  
Flexural Behavior ◽  
Low Velocity Impact ◽  
Woven Composites ◽  
Low Velocity ◽  
Electrospinning Technique ◽  
Structural Applications ◽  
Fiberglass Composite

High specific modulus and strength are one of the most desired properties of the materials for structural applications with applications in automotive, defense, aerospace etc. The major cause of failures in composite laminates is due to delaminations. These delaminations in composite laminates can occur due to various loadings such as, low velocity impact, fatigue etc. Conventional methods have like through the thickness stitching or Z-Pinning have limitations for improving flexural and interlaminar properties in woven composites, as while improving interlaminar properties, the in plane properties are affected. Non-woven Tetra Ethyl Orthosilicate (TEOS) electrospun nanofibers (ENFs) applied at interfacial regions offer an alternative option to traditional treatments to improve the flexural properties. This study investigates the flexural behavior of fiberglass composite interleaved with TEOS ENFs. The chemically engineered TEOS ENFs were manufactured using electrospinning technique and then sintered. The glass fiber composites with and without interleaving of non-woven TEO ENFs mats were manufactured using a heated vacuum assisted resin transfer molding (H-VARTM). The flexural strength and modulus of nanomodified composite are increased by 14% and 8% respectively; and the strain energy absorption has significantly increased up to 93% with 2% wt. of TEOS ENFs that shows significant improvement in impact resistance.

scholarly journals Reactive Powder Concrete Beam's Behavior in Flexural : Review

2021 ◽  
Vol 14 (4) ◽  
pp. 113-131
Author(s):  
Sheelan Mahmoud Hama ◽  
Dhifaf Natiq Hamdullah ◽  
Shaho Mahmoud Hama
Keyword(s):  
Coarse Aggregate ◽  
Concrete Beams ◽  
State Of The Art ◽  
Flexural Behavior ◽  
Structural Behavior ◽  
Reactive Powder Concrete ◽  
Stress Strain Relation ◽  
Structural Applications ◽  
Bending Load ◽  
Reactive Powder

Reactive Powder Concrete can be considered  as a special type of concrete in which the coarse aggregate will be eliminated to get a homogenous microstructure with a maximum density for final result. Many researchers presented a state of the art review on reactive powder's production,  mechanical properties, durability, development and applications. But the review about structural behavior is hardly to found. Because of importance of this type of concrete and its structural applications. This paper focused on review the researchers that deals with structural behavior of reactive powder concrete beams under bending load. Also review the proposed design equations related with reactive concrete behavior.  Before starting a review of strength , stress-strain relation and  ductility are presented because of their importance and effect on structure behavior of beams under bending. According to review of previous studies the type of fibers and its content as volumetric ratio, type of pozalanic materials and its content , amount of longitudinal steel reinforcement  are main factors that affected the flexural behavior of  reinforced Reactive Powder Concrete

scholarly journals Flexural Behavior of a Novel Textile-Reinforced Polymer Concrete

Polymers ◽  
2022 ◽  
Vol 14 (1) ◽  
pp. 176
Author(s):  
Daniel Heras Murcia ◽  
Bekir Çomak ◽  
Eslam Soliman ◽  
Mahmoud M. Reda Taha
Keyword(s):  
Peak Load ◽  
Basalt Fiber ◽  
Flexural Behavior ◽  
Image Processing Technique ◽  
Polymer Concrete ◽  
Textile Reinforced Concrete ◽  
Polymer Resin ◽  
Reinforced Polymer ◽  
Structural Applications ◽  
Textile Fabric

Textile reinforced concrete (TRC) has gained attention from the construction industry due to its light weight, high tensile strength, design flexibility, corrosion resistance, and remarkably long service life. Some structural applications that utilize TRC components include precast panels, structural repair, waterproofing elements, and façades. TRC is produced by incorporating textile fabrics into thin cementitious concrete panels. Premature debonding between the textile fabric and concrete due to improper cementitious matrix impregnation of the fibers was identified as a failure-governing mechanism. To overcome this performance limitation, in this study, a novel type of TRC is proposed by replacing the cement binder with a polymer resin to produce textile reinforced polymer concrete (TRPC). The new TRPC is created using a fine-graded aggregate, methyl methacrylate polymer resin, and basalt fiber textile fabric. Four different specimen configurations were manufactured by embedding 0, 1, 2, and 3 textile layers in concrete. Flexural performance was analyzed and compared with reference TRC specimens with similar compressive strength and reinforcement configurations. Furthermore, the crack pattern intensity was determined using an image processing technique to quantify the ductility of TRPC compared with conventional TRC. The new TRPC improved the moment capacity compared with TRC by 51%, 58%, 59%, and 158%, the deflection at peak load by 858%, 857%, 3264%, and 3803%, and the toughness by 1909%, 3844%, 2781%, and 4355% for 0, 1, 2, and 3 textile layers, respectively. TRPC showed significantly improved flexural capacity, superior ductility, and substantial plasticity compared with TRC.

scholarly journals Mechanical Properties and Flexural Behavior of Sustainable Bamboo Fiber-Reinforced Mortar

2020 ◽  
Vol 10 (18) ◽  
pp. 6587 ◽  
Author(s):  
Marcus Maier ◽  
Alireza Javadian ◽  
Nazanin Saeidi ◽  
Cise Unluer ◽  
Hayden K. Taylor ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Fracture Toughness ◽  
Construction Material ◽  
High Volume ◽  
Bamboo Fiber ◽  
Flexural Behavior ◽  
Fiber Reinforced ◽  
Structural Applications ◽  
Bamboo Fibers ◽  
By Products

In this study, a sustainable mortar mixture is developed using renewable by-products for the enhancement of mechanical properties and fracture behavior. A high-volume of fly ash—a by-product of coal combustion—is used to replace Portland cement while waste by-products from the production of engineered bamboo composite materials are used to obtain bamboo fibers and to improve the fracture toughness of the mixture. The bamboo process waste was ground and size-fractioned by sieving. Several mixes containing different amounts of fibers were prepared for mechanical and fracture toughness assessment, evaluated via bending tests. The addition of bamboo fibers showed insignificant losses of strength, resulting in mixtures with compressive strengths of 55 MPa and above. The bamboo fibers were able to control crack propagation and showed improved crack-bridging effects with higher fiber volumes, resulting in a strain-softening behavior and mixture with higher toughness. The results of this study show that the developed bamboo fiber-reinforced mortar mixture is a promising sustainable and affordable construction material with enhanced mechanical properties and fracture toughness with the potential to be used in different structural applications, especially in developing countries.

scholarly journals Experimental Tests on Fiber-Reinforced Alkali-Activated Concrete Beams Under Flexure: Some Considerations on the Behavior at Ultimate and Serviceability Conditions

Materials ◽  
2019 ◽  
Vol 12 (20) ◽  
pp. 3356
Author(s):  
Linda Monfardini ◽  
Luca Facconi ◽  
Fausto Minelli
Keyword(s):  
Fly Ash ◽  
Portland Cement ◽  
Experimental Results ◽  
Flexural Behavior ◽  
Experimental Program ◽  
Fiber Reinforced ◽  
Limit States ◽  
Structural Applications ◽  
Alkali Activated Concrete ◽  
Alkali Activated

Alkali-activated concrete (AAC) is an alternative concrete typology whose innovative feature, compared to ordinary concrete, is represented by the use of fly ash as a total replacement of Portland cement. Fly ash combined with an alkaline solution and cured at high temperature reacts to form a geopolymeric binder. The growing interest in using AACs for structural applications comes from the need of reducing the global demand of Portland cement, whose production is responsible for about 9% of global anthropogenic CO2 emissions. Some research studies carried out in the last few years have proved the ability of AAC to replace ordinary Portland cement concrete in different structural applications including the construction of beams and panels. On the contrary, few experimental results concerning the structural effectiveness of fiber-reinforced AAC are currently available. The present paper presents the results of an experimental program carried out to investigate the flexural behavior of full-scale AAC beams reinforced with conventional steel rebars, in combination with fibers uniformly spread within the concrete matrix. The experimental study included two beams containing 25 kg/m3 (0.3% in volume) of high-strength steel fibers and two beams reinforced with 3 kg/m3 (0.3% in volume) of synthetic fibers. A reference beam not containing fibers was also tested. The discussion of the experimental results focuses on some aspects significant for the structural behavior at ultimate limit states (ULS) and serviceability limit states (SLS). The discussion includes considerations on the flexural capacity and ductility of the test specimens. About the behavior at the SLS, the influence of fiber addition on the tension stiffening mechanism is discussed, together with the evolution of post-cracking stiffness and of the mean crack spacing. The latter is compared with the analytical predictions provided by different formulations developed over the past 40 years and adopted by European standards.

Structure-property relations of a natural composite: Bamboo guadua angustifolia, under impact and flexural loads

2021 ◽  
pp. 002199832110029
Author(s):  
José J Rua ◽  
Mario F Buchely ◽  
Sergio Neves Monteiro ◽  
Henry A Colorado
Keyword(s):  
Impact Analysis ◽  
Natural Fiber ◽  
Split Hopkinson Pressure Bar ◽  
Fiber Composite ◽  
Flexural Behavior ◽  
Structure Property ◽  
Hopkinson Pressure Bar ◽  
Suitable Alternative ◽  
Structural Applications ◽  
The Impact

In this work a natural fiber composite material, the Guadua Angustifolia Kunth from the family of Bamboo is investigated as a suitable alternative for solutions for impact applications, load-bearing, and other structural applications. Since this type of Bamboo grows faster than wood and requires less water and area to reach maturity and be able to crop, it is a competitive, economically, and environmentally solution when is compared to other construction materials. The Bamboo species of interest is a natural one from Colombia and will be evaluated in flexural behavior and under impact response to understand the material subjected under fast loading. Flexural samples were cut parallel to bamboo axial fibers to obtain the highest impact strength. The flexural tests and scanning electron microscopy characterization were included for microstructure analysis. Additionally, compression at high strain rates was characterized by a split-Hopkinson pressure bar (SHPB). Results show flexural strength of about 70 MPa. The impact analysis showed a tough material with very similar values to Charpy notched and dynamic instrumented impact tests.

Lattice Imaging of Grain Boundaries in Ceramics

1977 ◽  
Vol 35 ◽  
pp. 114-115
Author(s):  
D. R. Clarke ◽  
G. Thomas
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Silicon Nitride ◽  
Grain Boundaries ◽  
High Temperature Strength ◽  
Current Interest ◽  
Lattice Imaging ◽  
Special Significance ◽  
Structural Applications ◽  
Refractory Ceramics

Grain boundaries have long held a special significance to ceramicists. In part, this has been because it has been impossible until now to actually observe the boundaries themselves. Just as important, however, is the fact that the grain boundaries and their environs have a determing influence on both the mechanisms by which powder compaction occurs during fabrication, and on the overall mechanical properties of the material. One area where the grain boundary plays a particularly important role is in the high temperature strength of hot-pressed ceramics. This is a subject of current interest as extensive efforts are being made to develop ceramics, such as silicon nitride alloys, for high temperature structural applications. In this presentation we describe how the techniques of lattice fringe imaging have made it possible to study the grain boundaries in a number of refractory ceramics, and illustrate some of the findings.

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