Investigation flexural behavior of hybrid-reinforced layered filament wound pipes using experimental tests and numerical model

2021 ◽  
pp. 152808372110342
Author(s):  
Mehrdad Masoumi ◽  
Sayyed Behzad Abdellahi ◽  
Sayyed Mahdi Hejazi
Keyword(s):  
Flexural Strength ◽  
Experimental Tests ◽  
Element Model ◽  
Filament Winding ◽  
Experimental Results ◽  
Flexural Behavior ◽  
Bending Test ◽  
Three Point Bending ◽  
Filament Wound ◽  
Composite Samples

In the present study, filament wound pipes were fabricated by glass and polypropylene (PP) yarns with the three different filament winding angles 55°, 70°, and 82°. Glass and PP yarns were wound around the pipe with two methods; layered and hybrid. Epoxy resin was applied as a matrix to manufacture composite samples. It should be mentioned that composite samples were made in different layers. The three-point bending test was carried out on all samples to investigate the bending behavior of the composites. The experimental results showed that the winding angle 55° is better than other angles in terms of improving the flexural strength of the composite. Moreover, using hybrid yarn to fabricate the composite sample increases the flexural strength and energy absorption of the composite. In the next step, a multi-scale finite element model was applied to predict the flexural behavior of the composites. In this model, a unit-cell of each composite structure was modeled at the meso scale and elastic constants of the composites were extracted by a Python code. In addition, failure parameters for the composites were determined according to micromechanical equations. All elastic and failure parameters were utilized for the macro model and simulation three-point bending test. The numerical results were compared with the experimental and a good agreement could be observed between numerical and experimental results. So, the proposed model is proper to predict the mechanical behavior of the filament wound composite with high accuracy.

Investigation of tensile and flexural behavior of biaxial and rib 1 × 1 weft-knitted composite using experimental tests and multi-scale finite element modeling

2019 ◽  
Vol 53 (23) ◽  
pp. 3201-3215 ◽  
Author(s):  
Reza Hessami ◽  
Aliasghar Alamdar Yazdi ◽  
Abbas Mazidi
Keyword(s):  
Finite Element ◽  
Finite Element Modeling ◽  
Experimental Results ◽  
Flexural Behavior ◽  
Bending Tests ◽  
Three Point Bending ◽  
Element Modeling ◽  
Multi Scale ◽  
Scale Modeling ◽  
Composite Samples

In this study, tensile and flexural behavior of biaxial and rib weft-knitted composite is obtained numerically and experimentally. Multi-scale finite element modeling is employed to simulate the tensile and flexural behavior of composite samples. In the finite element modeling, the geometry of a unit cell of each fabric is initially modeled in ABAQUS software, and then periodic boundary conditions were applied to a unit cell. The stiffness matrix for each structure was obtained by a python code via meso scale modeling and used as input data for the macro modeling. To validate the numerical model, two types of weft-knitted fabrics (rib 1 × 1 and biaxial fabrics) are produced by a flat weft knitting machine. Epoxy resin is used to construct composite by the vacuum injection process (VIP). After that, the tensile and three-point bending tests were applied to composite samples. The experimental results showed that tensile strength and tensile modulus of biaxial composites are greater than rib composites, in both wale and course directions. Moreover, in three-point bending test, biaxial composite showed more strength and more stiffness in comparison to rib composite. Finite element results were compared to experimental results in tensile and bending tests. The results showed that good agreement with experimental results in the linear section of tensile and flexural behavior of composites. Consequently, the current multi-scale modeling can be used to predict the stiffness matrix and mechanical behavior of complex composite structures such as knitted composites.

scholarly journals Experimental on Flexural Strength of Glass/Kevlar and Glass/Carbon Hybrid Composite Laminates

2019 ◽  
Vol 8 (12S) ◽  
pp. 45-48
Keyword(s):  
Flexural Strength ◽  
Hybrid Composite ◽  
Composite Laminates ◽  
Experimental Results ◽  
Bending Test ◽  
Three Point Bending ◽  
Stacking Order ◽  
Glass Carbon ◽  
Hybrid Laminates

our present study deals with the investigation of flexural strength of Glass/Kevlar epoxy and glass/carbon epoxy hybrid laminates. Laminates of different stacking order were prepared and three point bending test were conducted on the hybrid laminates. From the experimental results, the flexural strength of different hybrid laminates was evaluated and comparisons were made.

Flexural behavior of functionally graded polymeric composite beams

2021 ◽  
pp. 152808372110003
Author(s):  
M Atta ◽  
A Abu-Sinna ◽  
S Mousa ◽  
HEM Sallam ◽  
AA Abd-Elhady
Keyword(s):  
Flexural Strength ◽  
Volume Fraction ◽  
Stress Gradient ◽  
Polymeric Composite ◽  
Composite Beams ◽  
Functionally Graded ◽  
Flexural Behavior ◽  
Bending Test ◽  
Polymeric Composite Material ◽  
Fiber Volume

The bending test is one of the most important tests that demonstrates the advantages of functional gradient (FGM) materials, thanks to the stress gradient across the specimen depth. In this research, the flexural response of functionally graded polymeric composite material (FGM) is investigated both experimentally and numerically. Fabricated by a hand lay-up manufacturing technique, the unidirectional glass fiber reinforced epoxy composite composed of ten layers is used in the present investigation. A 3-D finite element simulation is used to predict the flexural strength based on Hashin’s failure criterion. To produce ten layers of FGM beams with different patterns, the fiber volume fraction ( Vf%) ranges from 10% to 50%. A comparison between FGM beams and conventional composite beams having the same average Vf% is made. The experimental results show that the failure of the FGM beams under three points bending loading (3PB) test is initiated from the tensioned layers, and spread to the upper layer. The spreading is followed by delamination accompanied by shear failures. Finally, the FGM beams fail due to crushing in the compression zone. Furthermore, the delamination failure between the layers has a major effect on the rapidity of the final failure of the FGM beams. The present numerical results show that the gradient pattern of FGM beams is a critical parameter for improving their flexural behavior. Otherwise, Vf% of the outer layers of the FGM beams, i.e. Vf% = 30, 40, or 50%, is responsible for improving their flexural strength.

Flexural Behavior of Six Species of Italian Bamboo

2022 ◽  
Author(s):  
Silvia Greco ◽  
Luisa Molari
Keyword(s):  
Structural Material ◽  
Flexural Strength ◽  
Mechanical Performance ◽  
Functionally Graded ◽  
Flexural Behavior ◽  
Bending Test ◽  
Bamboo Species ◽  
Four Point Bending ◽  
Flexural Ductility ◽  
Graded Material

The good mechanical performance of bamboo, coupled with its sustainability, has boosted the idea to use it as a structural material. In some areas of the world it is regularly used in constructions but there are still countries in which there is a lack of knowledge of the mechanical properties of the locally-grown bamboo, which limits the spread of this material. Bamboo is optimized to resist to flexural actions with its peculiar micro structure along the thickness in which the amount of fibers intensifies towards the outer layer and the inner part is composed mostly of parenchyma. The flexural strength depends on the amount of fibers, whereas the flexural ductility is correlated to the parenchyma content. This study focuses on the flexural strength and ductility of six different species of untreated bamboo grown in Italy. A four-point bending test was carried out on bamboo strips in two different loading configurations relating to its microstructure. Deformation data are acquired from two strain gauges in the upper and lower part of the bamboo beam. Difference in shape and size of Italian bamboo species compared to the ones traditionally used results in added complexity when performing the tests. Such difficulties and the found solutions are also described in this work. The main goal is to reveal the flexural behavior of Italian bamboo as a functionally graded material and to expand the knowledge of European bamboo species toward its use as a structural material not only as culm but also as laminated material.

Assessment of Fracture Toughness Using Small Punch Tests of Prenotched Specimens

2017 ◽  
Vol 139 (5) ◽  
Author(s):  
Yangyan Zheng ◽  
Xiao Chen ◽  
Zheng Yang ◽  
Xiang Ling
Keyword(s):  
Fracture Toughness ◽  
Numerical Simulations ◽  
Stress Gradient ◽  
Element Model ◽  
Bending Test ◽  
J Integral ◽  
Notched Specimen ◽  
Small Punch ◽  
Three Point Bending ◽  
The Difference

In this paper, line- and ring-notched small punch test (SPT) specimens were studied; a three-dimensional (3D) model of a ring-notched SPT specimen was established using the contour integral method, and the validity of the model was verified using ring-notched specimens. The stress and strain fields were analyzed using numerical simulations of a ring-notched SPT specimen, and the change in the stress gradient during deformation was considered. To verify the finite element model, the results of the numerical simulations were compared with those of three-point bending tests and a Gurson–Tvergaard–Needleman (GTN) model. Compared with the line-notched specimen, the ring-notched specimen was more suitable for notch propagation analysis and fracture toughness evaluation. The results of the numerical simulations were in good agreement with those of the experiments, which showed that the numerical model used in this study was correct. For a notch that initiated when the load reached its maximum value, the value of the J integral was 335 × 10−6 kJ/mm2, and at time 0.85Pmax, the value of the J integral was 201 × 10−6 kJ/mm2, and the difference from the result of the three-point bending test was 14.4%. For a notch that initiated during the stretching deformation stage, the relevant fracture toughness was 225 × 10−6 kJ/mm2, and the difference from the result of the three-point bending test was 3%.

Flexural Behavior of Sandwich Structure with AA 8011 Honeycomb Core and Al 1100 Face Skins

2018 ◽  
Vol 10 (6) ◽  
Author(s):  
M.R. Ashok ◽  
M. Manojkumar ◽  
P.V. Inbanaathan ◽  
R. Shanmuga Prakash
Keyword(s):  
Finite Element Analysis ◽  
Sandwich Structure ◽  
Flexural Behavior ◽  
Bending Test ◽  
Honeycomb Core ◽  
Element Analysis ◽  
Three Point Bending ◽  
The Core ◽  
Flexural Testing ◽  
The Face

This paper details the fabrication and flexural testing of sandwich structure with Aluminium honeycomb core with Aluminium face skins. The material for the face skin is aluminium 1100 and for the core is Aluminium AA8011. The cell size obtained by fabrication is 7mm. The specimen is prepared and tested as per the ASTM standard C393/C393M-11 on a three-point bending test to obtain the ultimate core shear strength and the face skin strength. Finite element analysis is also carried out to validate the experimental test.

Experimental Determination of the Ultimate Strength of Box Girder Specimens

2016 ◽  
Author(s):  
Thomas Lindemann ◽  
Patrick Kaeding ◽  
Eldor Backhaus
Keyword(s):  
Finite Element ◽  
Experimental Determination ◽  
Ultimate Strength ◽  
Progressive Collapse ◽  
Bending Moment ◽  
Element Model ◽  
Experimental Results ◽  
Bending Test ◽  
Box Girder

The Finite Element Method (FEM) is a feasible tool to perform progressive collapse analyses of large structural systems. Despite enormous developments in finite element formulations and computer technologies the results of structural analyses should be validated against experimental results. In this paper the collapse behaviour of two identical box girder specimens is determined experimentally for the load case of pure longitudinal bending. The specimens are composed of stiffened plate panels and connected at either ends to a loading structure. Within a 4-point bending test a constant bending moment is applied to each specimen to determine the collapse behaviour even in the post-ultimate strength range. The results of the experimental determination of the ultimate strength are presented for the box girder specimens. To simulate the collapse behaviour a finite element model is used and validated against experimental results.

THE INFLUENCE OF SiC COATING PROCESS ON THE PROPERTIES OF C/C COMPOSITES

2007 ◽  
Vol 14 (04) ◽  
pp. 817-820
Author(s):  
MIN HUANG ◽  
KE-ZHI LI ◽  
HE-JUN LI ◽  
QIAN-GANG FU ◽  
GUO-DONG SUN
Keyword(s):  
Mechanical Properties ◽  
Flexural Strength ◽  
Failure Mode ◽  
Flexural Modulus ◽  
Pack Cementation ◽  
Bending Test ◽  
Carbon Composites ◽  
Coating Process ◽  
Three Point Bending ◽  
Coated Carbon

SiC coating for carbon/carbon composites was prepared by pack cementation method. The effects of coating process on the microstructure and the mechanical properties of C / C composites were analyzed by SEM and three-point bending test, respectively. As the infiltrated Si improved the interfaces bonding during the coating process, the flexural strength and flexural modulus of SiC -coated carbon/carbon composites were both increased by about 10% than the naked C / C composites. In addition, the mechanism of the change of failure mode of SiC coated C / C composites and naked C / C composites was addressed.

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