scholarly journals CRACKING AND STRAIN ANALYSIS OF BEAMS REINFORCED WITH COMPOSITE BARS / KOMPOZITINIAIS STRYPAIS ARMUOTŲ SIJŲ PLEIŠĖJIMO IR DEFORMACIJŲ ANALIZĖ

2012 ◽  
Vol 4 (4) ◽  
pp. 346-350
Author(s):  
Edgaras Timinskas ◽  
Ronaldas Jakubovskis ◽  
Adas Meškėnas ◽  
Eugenijus Gudonis
Keyword(s):  
Strain Analysis ◽  
Ductile Failure ◽  
Plain Concrete ◽  
Experimental Results ◽  
Steel Fibres ◽  
Ordinary Concrete ◽  
Finite Element Software ◽  
Average Crack ◽  
Short Steel Fibres ◽  
Good Agreement

The paper discusses the results of experimental and numerical modelling using two beams reinforced with GFRP bars. One beam was made of plain concrete while the other contained short steel fibres. The influence of steel fibres on deflection and cracking behaviour was studied. A comparative analysis of experimental results has shown that steel fibres significantly reduce deflections and average crack width of the beam. Moreover, an addition of steel fibres to the concrete mix led to a more ductile failure mode of the beam. Numerical analysis employing nonlinear finite element software ATENA has revealed that a good agreement between calculated and experimental results regarding an ordinary concrete GFRP reinforced beam can be obtained. Santrauka Kompozitinės armatūros taikymas betono konstrukcijoms dažnai sukelia šias problemas: neleistinai didelius įlinkius ir atsiveriančius plyšio pločius, trapų konstrukcijų irimą. Straipsnyje pateikiami dviejų vienodos geometrijos kompozitiniais stiklo pluošto strypais armuotų sijų eksperimentiniai ir skaitiniai tyrimai. Vienoje iš sijų į betono mišinį papildomai įdėta plieno plaušo fibrų. Bandymo metu matuoti vidutiniai sijų kreiviai, įlinkiai ir atsiveriantys plyšio pločiai. Atlikus lyginamąją analizę pastebėta, kad plieno plaušo naudojimas padidina stiklo pluoštu armuotų sijų standumą, atsparumą pleišėjimui, sijų suirimo pobūdis tampa plastiškesnis. Sijas sumodeliavus netiesine baigtinių elementų programa ATENA gautas geras eksperimentinių ir skaitinių rezultatų sutapimas įprasto betono stiklo pluošto armatūra armuotai sijai.

Finite Element Modelling of TBC Failure Mechanisms by Using XFEM

2018 ◽  
Author(s):  
Safa Mesut Bostancı ◽  
Ercan Gürses ◽  
Demirkan Çöker
Keyword(s):  
Finite Element ◽  
Thermal Barrier Coatings ◽  
Failure Mechanisms ◽  
Crack Spacing ◽  
Experimental Results ◽  
Thermal Barrier ◽  
Barrier Coatings ◽  
Finite Element Software ◽  
Four Point Bending ◽  
Average Crack

Thermal Barrier Coatings have been widely used in modern turbine engines to protect the nickel based metal substrate from the high temperature service conditions, 1600–1800 K. In this study, some of the failure mechanisms of typical Air Plasma Sprayed Thermal Barrier Coatings (TBC) used in after-burner structures composed of three major layers: Inconel 718 substrate, NiCrAlY based metallic bond coat (BC) and Yttria Stabilized Zirconia (YSZ) based ceramic top coat (TC) are investigated. Investigation of the cracking mechanism of TBC in terms of design and performance is very important because the behavior of TBCs on ductile metallic substrates is brittle. To this end, four-point bending experiments conducted in Kütükoğlu (2015) is analyzed by using the Extended Finite Element Method (XFEM). All the analyses are conducted with the commercial finite element software ABAQUS. Three different models with varying TC and BC thicknesses are studied under four-point bending. It is observed that multiple vertical cracks are initiated in the TC. Cracks initiate at the top of YSZ and propagate through the whole TC. It is observed that the average crack spacing increases with the increasing thickness of the TC. Numerical results are found to be consistent with the experimental results. In other words, the average crack spacing for three different models are similar with the experimental results.

Research on Flexural Behavior of Coarse Recycled Aggregate-Filled Plain Concrete Beam

2011 ◽  
Vol 250-253 ◽  
pp. 379-382
Author(s):  
Jing Li ◽  
Lin Fu Wang ◽  
Juan Li ◽  
Xian Feng Qu ◽  
Lin Jang
Keyword(s):  
Concrete Beam ◽  
Concrete Beams ◽  
Plain Concrete ◽  
Recycled Aggregate ◽  
Flexural Behavior ◽  
Recycled Aggregates ◽  
Ordinary Concrete ◽  
Finite Element Software ◽  
Damage Process ◽  
Better Than

In order to study the flexural behavior of coarse recycled aggregate-filled plain concrete beams, two beams were made. The experiment of simply supported beam under concentrated loads is performed, which makes us get the ultimate flexural capacity, midspan deflection and the development of cracks of each beam, and the numerical simulation of the damage process of beams is also carried out using finite element software. The results indicated that the tension property of coarse recycled aggregate-filled plain concrete beam is better than ordinary concrete beam, and some failure forms of bending is similar; the strength of recycled aggregates greatly influences flexural behavior of coarse recycled aggregate-filled plain concrete beam.

Evaluation of superior layer configuration of titanium Ti-6Al-4V and aluminium 2024-T3 against soft projectiles

2021 ◽  
pp. 204141962110357
Author(s):  
K. Senthil ◽  
Rachit Sharma ◽  
S. Rupali ◽  
Ankush Thakur ◽  
M. A. Iqbal ◽  
...  
Keyword(s):  
Material Model ◽  
Experimental Results ◽  
Equivalent Thickness ◽  
Explicit Finite Element ◽  
Ballistic Resistance ◽  
Finite Element Software ◽  
Target Configuration ◽  
Titanium Target ◽  
The Difference ◽  
Good Agreement

The manuscript is focussed on the prediction of superior layer configuration on titanium and aluminium plates through numerical investigations using ABAQUS/Explicit finite element software. The target plate of titanium Ti-6Al-4V (Ti) and aluminium Al 2024-T3 (Al) were studied against 7.62 mm diameter soft lead core projectiles. The Johnson-Cook (JC) material model was employed to simulate the behaviour of the target as well as projectile material. The results thus predicted from the numerical simulations in terms of deformed profile, residual velocity and ballistic limit were compared with the experimental results available in literature. Overall, the results were found in good agreement with the experimental results. The simulations were performed on the target of 10, 12.7 and 15 mm thickness with three, five and ten layers in order to predict the superior layer configuration. In the case of Ti-6Al-4V, the difference in performance between three layers and monolithic was quite high, however the use of five or ten layers of equivalent thickness is not advisable as performance is reduced. For Al2024-T3, the performance of layer targets was quite similar to that of monolithic targets. It is also observed the resistance of TiTiAl target configuration found to be better as compared to AlTiTi target configuration. It is concluded that the Al plate as back layer has more efficiency for ballistic resistance of layered configuration. It is also concluded that with respect to thickness, the capacity of titanium target is approximately 1.5 times higher than aluminium target against given lead core projectile.

Inducing Frictional Force to Enhance the Transient Response in Beams

2019 ◽  
Vol 22 (2) ◽  
pp. 88-93
Author(s):  
Hamed Khanger Mina ◽  
Waleed K. Al-Ashtrai
Keyword(s):  
Numerical Analysis ◽  
Transient Response ◽  
Frictional Force ◽  
Damping Ratio ◽  
Experimental Results ◽  
Damping Capacity ◽  
Tightening Force ◽  
Contact Areas ◽  
Good Agreement ◽  
Ansys Workbench

This paper studies the effect of contact areas on the transient response of mechanical structures. Precisely, it investigates replacing the ordinary beam of a structure by two beams of half the thickness, which are joined by bolts. The response of these beams is controlled by adjusting the tightening of the connecting bolts and hence changing the magnitude of the induced frictional force between the two beams which affect the beams damping capacity. A cantilever of two beams joined together by bolts has been investigated numerically and experimentally. The numerical analysis was performed using ANSYS-Workbench version 17.2. A good agreement between the numerical and experimental results has been obtained. In general, results showed that the two beams vibrate independently when the bolts were loosed and the structure stiffness is about 20 N/m and the damping ratio is about 0.008. With increasing the bolts tightening, the stiffness and the damping ratio of the structure were also increased till they reach their maximum values when the tightening force equals to 8330 N, where the structure now has stiffness equals to 88 N/m and the damping ratio is about 0.062. Beyond this force value, increasing the bolts tightening has no effect on stiffness of the structure while the damping ratio is decreased until it returned to 0.008 when the bolts tightening becomes immense and the beams behave as one beam of double thickness.

PHOTOINDUCED NONLINEAR OCTUPOLAR POLARIZATION: TRANSIENT AND PERMANENT REGIMES

1996 ◽  
Vol 05 (04) ◽  
pp. 653-670 ◽  
Author(s):  
CÉLINE FIORINI ◽  
JEAN-MICHEL NUNZI ◽  
FABRICE CHARRA ◽  
IFOR D.W. SAMUEL ◽  
JOSEPH ZYSS
Keyword(s):  
Theoretical Analysis ◽  
Second Harmonic ◽  
Experimental Results ◽  
Polar Field ◽  
Rotational Spectrum ◽  
Dual Frequency ◽  
One Dimensional ◽  
Ethyl Violet ◽  
Disperse Red 1 ◽  
Good Agreement

An original poling method using purely optical means and based on a dual-frequency interference process is presented. We show that the coherent superposition of two beams at fundamental and second-harmonic frequencies results in a polar field with an irreducible rotational spectrum containing both a vector and an octupolar component. This enables the method to be applied even to molecules without a permanent dipole such as octupolar molecules. After a theoretical analysis of the process, we describe different experiments aiming at light-induced noncentrosymmetry performed respectively on one-dimensional Disperse Red 1 and octupolar Ethyl Violet molecules. Macroscopic octupolar patterning of the induced order is demonstrated in both transient and permanent regimes. Experimental results show good agreement with theory.

scholarly journals Hot Deformation Behavior and Dynamic Recrystallization of Ultra High Strength Steel

Metals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 1239
Author(s):  
Liping Zhong ◽  
Bo Wang ◽  
Chundong Hu ◽  
Jieyu Zhang ◽  
Yu Yao
Keyword(s):  
Martensitic Steel ◽  
High Strength ◽  
Experimental Results ◽  
Hot Deformation Behavior ◽  
Thermal Compression ◽  
Forging Process ◽  
Finite Element Software ◽  
Ultra High Strength Steel ◽  
Recrystallized Grain Size ◽  
Deform 3D

In this paper, in order to improve the microstructure uniformity of an ultra-high strength martensitic steel with a strength greater than 2500 MPa developed by multi-directional forging in the laboratory, a single-pass hot compression experiment with the strain rate of 0.01 to 1 s−1 and a temperature of 800 to 1150 °C was conducted. Based on the experimental data, the material parameters were determined, the constitutive model considering the influence of work hardening, the recrystallization softening on the dislocation density, and the recrystallized grain size model were established. After introducing the model into the finite element software DEFORM-3D, the thermal compression experiment was simulated, and the results were consistent with the experimental results. The rule for obtaining forging stock with a uniform and refinement microstructure was acquired by comparing the simulation and the experimental results, which are helpful to formulate an appropriate forging process.

scholarly journals Comparison of Experimental and Numerical Transient Drop Deformation during Transition through Orifices in High-Pressure Homogenizers

2021 ◽  
Vol 5 (3) ◽  
pp. 32
Author(s):  
Benedikt Mutsch ◽  
Peter Walzel ◽  
Christian J. Kähler
Keyword(s):  
High Pressure ◽  
Visual Analysis ◽  
Imaging Technique ◽  
Extensional Flow ◽  
Droplet Breakup ◽  
Experimental Results ◽  
Drop Deformation ◽  
Droplet Deformation ◽  
Shadow Imaging ◽  
Good Agreement

The droplet deformation in dispersing units of high-pressure homogenizers (HPH) is examined experimentally and numerically. Due to the small size of common homogenizer nozzles, the visual analysis of the transient droplet generation is usually not possible. Therefore, a scaled setup was used. The droplet deformation was determined quantitatively by using a shadow imaging technique. It is shown that the influence of transient stresses on the droplets caused by laminar extensional flow upstream the orifice is highly relevant for the droplet breakup behind the nozzle. Classical approaches based on an equilibrium assumption on the other side are not adequate to explain the observed droplet distributions. Based on the experimental results, a relationship from the literature with numerical simulations adopting different models are used to determine the transient droplet deformation during transition through orifices. It is shown that numerical and experimental results are in fairly good agreement at limited settings. It can be concluded that a scaled apparatus is well suited to estimate the transient droplet formation up to the outlet of the orifice.

Simulation of Sphere’s Motion Induced by Shock Waves

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
Dan Igra ◽  
Ozer Igra ◽  
Lazhar Houas ◽  
Georges Jourdan
Keyword(s):  
Shock Waves ◽  
Drag Coefficient ◽  
Drag Force ◽  
Stationary Flow ◽  
Experimental Results ◽  
Experimental Findings ◽  
Sphere Drag ◽  
Simulation Scheme ◽  
Good Agreement

Simulations of experimental results appearing in Jourdan et al. (2007, “Drag Coefficient of a Sphere in a Non-Stationary Flow: New Results,”Proc. R. Soc. London, Ser. A, 463, pp. 3323–3345) regarding acceleration of a sphere by the postshock flow were conducted in order to find the contribution of the various parameters affecting the sphere drag force. Based on the good agreement found between present simulations and experimental findings, it is concluded that the proposed simulation scheme could safely be used for evaluating the sphere’s motion in the postshock flow.

Nonlinear Numerical Analysis of SRC Frame Middle Joints

2013 ◽  
Vol 376 ◽  
pp. 231-235
Author(s):  
Cheng Li ◽  
Yun Zou ◽  
Jie Kong ◽  
Zhi Wei Wan
Keyword(s):  
Finite Element ◽  
Numerical Analysis ◽  
Bearing Capacity ◽  
Axial Load ◽  
Load Ratio ◽  
Experimental Results ◽  
Steel Ratio ◽  
Finite Element Software ◽  
Axial Load Ratio ◽  
Hysteretic Performance

Nonlinear numerical analysis for the force performance of frame middle joint is processed in this paper with the finite element software of ABAQUS. Compared with experimental results, numerical analysis results are found to be reasonable. Then the influence of factors such as shaped steel ratio and axial-load ratio are contrastively analyzed. The results show that shaped steel ratio has a greater influence on the bearing capacity and hysteretic performance of the structure, but the axial-load ratio has less influence.

Viscoelastic Deformation of PC/ABS Alloy

2007 ◽  
Vol 353-358 ◽  
pp. 1229-1232
Author(s):  
Z.N. Yin ◽  
L.F. Fan ◽  
Tie Jun Wang
Keyword(s):  
Dynamic Mechanical Analysis ◽  
Relaxation Modulus ◽  
Mechanical Analysis ◽  
Experimental Results ◽  
Viscoelastic Deformation ◽  
Dynamic Mechanical ◽  
Storage And Loss Moduli ◽  
Static Relaxation ◽  
Comparison Of The Results ◽  
Good Agreement

Dynamic Mechanical Analysis (DMA) and static relaxation tests are carried out to study the viscoelastic deformation of PC/ABS alloy with blending ratio of PC to ABS being 50/50. A modified approach is developed to calculate the relaxation modulus of PC/ABS alloy from the DMA experimental results of storage and loss moduli. Comparison of the results obtained from DMA and static relaxation tests is presented and good agreement is found.

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