Inverse characterisation of gradient distribution of the modulus of bamboo using a four-point bending test

Holzforschung ◽  
2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Xianzhi Gao ◽  
Guangyan Liu ◽  
Lu Wang ◽  
Yanan Yi ◽  
Guang Lin ◽  
...  
Keyword(s):  
Elastic Modulus ◽  
Model Updating ◽  
Volume Fraction ◽  
Image Correlation ◽  
Bending Test ◽  
Uniaxial Tensile ◽  
Gradient Distribution ◽  
Outer Skin ◽  
Four Point Bending ◽  
Four Point Bending Test

AbstractAs a natural graded material, bamboo has gradually increasing elastic modulus along the radial direction from the inner to the outer skin. Accurate measurement of the modulus distribution plays an important role in bamboo-based structural design. However, it is difficult to characterise this modulus distribution by using conventional testing approaches on bamboo slices. A more effective method was developed in this study for the inverse identification of gradually varying material properties. The method is based on the digital image correlation and finite element model updating techniques. The radial distribution of the elastic modulus of bamboo was obtained through only one four-point bending test. The inversely identified modulus distribution was verified through uniaxial tensile tests on sliced bamboo strips and microscopic observation of the volume fraction distribution of its vascular bundle. The results showed that the elastic modulus of the bamboo material decreased from the outer skin (20 GPa) to the inner skin (2 GPa), which is in good consistence with the tensile test results on sliced specimens.

Modeling of Deformation and Fracture of Concrete Structures with FRP Reinforcement

2015 ◽  
Vol 752-753 ◽  
pp. 685-688
Author(s):  
Andrey Benin ◽  
S.G. Semenov ◽  
Artem S. Semenov
Keyword(s):  
Image Correlation ◽  
Bending Test ◽  
Four Point Bending ◽  
Reinforced Plastic ◽  
Deformation And Fracture ◽  
Different Types ◽  
Loading Case ◽  
Frp Reinforcement ◽  
Four Point Bending Test ◽  
Frp Bars

Carrying capacity and fracture modes of concrete beams reinforced by different types of fiber reinforced plastic (FRP) bars are analyzed experimentally and numerically. The four-point-bending test is used as a typical loading case for this purpose. Synchronous registration of loading level, displacements and strains is performed by using InstronTM servohydraulic machine, LVDT sensors, strain gauges and digital image correlation Vic3DTM system. The experimental data and results of finite element simulations are compared and discussed.

scholarly journals Investigation of the Elastic Modulus of Polymer Sleepers Under a Quasistatic and Cyclic Loading

2019 ◽  
Vol 15 (2) ◽  
pp. 125-133
Author(s):  
Vít Lojda ◽  
Aran van Belkom ◽  
Hana Krejčiříková
Keyword(s):  
Elastic Modulus ◽  
Cyclic Loading ◽  
Prestressed Concrete ◽  
Load Level ◽  
Bending Test ◽  
Elastic Behaviour ◽  
Loading Frequency ◽  
Wheel Load ◽  
Four Point Bending ◽  
Four Point Bending Test

AbstractIn ballasted track, the wheel load is transmitted to the subgrade via sleepers commonly made of impregnated wood, prestressed concrete, steel or recently developed polymer sleepers. Mentioned material types of sleepers are characterized by different elastic moduli being a key parameter in any numerical model. Hence, this paper aims to determine the elastic modulus of sleepers subjected to a laboratory four-point bending test. Traffic resembling load level of 60 kN adopted from a typical axle load distributed by the rails to the sleeper was applied in a quasistatic and cyclic loading. The samples included sleepers made of polymers complemented with wood and pre-stressed concrete. The results of this paper are based on the elastic modulus investigation. Main conclusions are focused on the sleeper’s elastic modulus under changing loading frequencies. Wood and prestressed concrete sleepers indicated mainly elastic behaviour resulting in a constant elastic modulus. However, polymer sleepers showed a loading frequency dependent elastic modulus as a result of their viscous elastic behaviour. Moreover, the conclusions of this paper involve E-modulus measurements of impregnated beech sleepers in order to describe their piece by piece elasticity variation due to their natural origin.

scholarly journals Estimation of the Modulus Fir Wood Reinforced With PBO Fiber Mesh

2018 ◽  
Vol 64 (4) ◽  
pp. 105-121
Author(s):  
P. Sokołowski ◽  
P. G. Kossakowski
Keyword(s):  
Elastic Modulus ◽  
Bearing Capacity ◽  
Modulus Of Elasticity ◽  
Bending Test ◽  
Load Bearing Capacity ◽  
Four Point Bending ◽  
University Of Technology ◽  
Pbo Fiber ◽  
Four Point Bending Test ◽  
Fiber Mesh

AbstractThis paper presents the results of preliminary tests for estimating the modulus of elasticity of wooden beams from firs reinforced with PBO fiber mesh. The tests were carried out in the Materials Strength Laboratory at the Kielce University of Technology in Kielce, Poland with PN-EN 408: 2004. The wooden elements were subjected to a four-point bending test with the aim of estimating the elastic modulus when bending, assuming the loading velocities of the loading forces of 5 mm / min. The obtained results show a significant increase in the load-bearing capacity of beams reinforced with PBO mesh.

Mechanical Properties of Fiber Reinforced Lime-Based Mortars Evaluated from Four-Point Bending Test

2016 ◽  
Vol 821 ◽  
pp. 526-531
Author(s):  
Michal Přinosil ◽  
Petr Kabele
Keyword(s):  
Thermal Effects ◽  
High Performance ◽  
Correlation Method ◽  
Image Correlation ◽  
Bending Test ◽  
Fiber Reinforced ◽  
Four Point Bending ◽  
High Performance Fiber ◽  
Bending Behavior ◽  
Four Point Bending Test

In the study, the bending behavior of high-performance fiber reinforced lime-based mortars is experimentally investigated using four-point bending test. From the experimental data, the influence of the mortar’s composition on its stiffness, cracking strength and ultimate strength are investigated. It is also studied, whether the response has strain-softening or strain-hardening character and whether the material exhibits multiple cracking. Such behavior is very important for the durability of the material, because it allows carrying load during imposed deformations (due to thermal effects, movements of foundations, seismicity, etc.). The number of formed cracks is examined using digital image correlation method. The mortar composition is considered with two types of binder (pure lime, lime-metakaolin), with two types of polyvinyl alcohol fibers in four volume fractions (0.5÷2.0%). As the reference, we consider two sets of specimens made of plain mortar without fiber reinforcement.

scholarly journals Structural behaviour of PSCC slab panel under four-point bending test

2021 ◽  
Vol 1144 (1) ◽  
pp. 012039
Author(s):  
M A Iman ◽  
N Mohamad ◽  
A A A Samad ◽  
Steafenie George ◽  
M A Tambichik ◽  
...  
Keyword(s):  
Bending Test ◽  
Structural Behaviour ◽  
Four Point Bending ◽  
Four Point Bending Test

Manufacturing a carbon/epoxy NACA 23018 airfoil skin using a circular braiding machine: experimental and numerical study

2021 ◽  
pp. 152808372199377
Author(s):  
Jalil Hajrasouliha ◽  
Mohammad Sheikhzadeh
Keyword(s):  
Numerical Study ◽  
Filament Winding ◽  
Bending Test ◽  
Elastic Response ◽  
Manufacturing Processes ◽  
Fiber Reinforced Composite ◽  
Four Point Bending ◽  
Reinforced Composite ◽  
Four Point Bending Test ◽  
Meso Scale

In the interest of reducing the weight and also cost of blade skins, various automatic preform manufacturing processes were developed including tape laying, filament winding and braiding. Among them, the circular braiding process was found to be an efficient method in producing seamless preforms on mandrels with various geometries. In this regard, an attempt was made to produce a carbon fiber reinforced composite with the shape of NACA 23018 airfoil using a circular braiding machine. Thus, suitable wooden mandrels were manufactured using NACA 23018 airfoil coordinates, which were obtained by assuming the perimeter of 20 cm. Furthermore, both biaxially and triaxially braided preforms were produced and subsequently impregnated with epoxy resin through an appropriate fabrication method. To assess their performance, four-point bending test was carried out on samples. Ultimately, the elastic response of braided composite airfoils was predicted using a meso-scale finite element modeling and was validated with experimental results.

Sign in / Sign up

Export Citation Format

Share Document