scholarly journals Stress Concentration Studies in Flat Plates with Rectangular Cut-Outs Using Finite Element Method

2019 ◽  
Vol 4 (1) ◽  
pp. 66-76 ◽  
Author(s):  
Dheeraj Gunwant
Keyword(s):  
Infinite Plate ◽  
Geometrical Parameters ◽  
Light Weight ◽  
Flat Plates ◽  
Uniaxial Load ◽  
Desirable Feature ◽  
Different Shapes ◽  
Stress States ◽  
Analytical Relations ◽  
Good Agreement

Presence of cut-outs of different shapes is inevitable and is many times considered to be a desirable feature for the design of light-weight components. However, the presence of such cut-outs induces highly localized stresses in their vicinity which cannot be resolved using analytical relations and elementary equations of the strength of materials. In the recent years, FEM has evolved as a crucial tool for handling such problems with reduced degree of complexity. The present investigation is aimed at studying the effect of various geometrical parameters and loading scenarios on the SCF induced in an infinite plate in presence of rectangular cut-out with filleted corners. In the first step, the model was subjected to uniaxial load and the obtained values of SCF exhibited good agreement with analytical values. The model was further subjected to systematically varied stress states and geometrical parameters in order to study their effect on the SCF.

An Analytical-Numerical Approach Concerning the Stresses and Deformations in Single-Strapped Adhesively Bonded Joints

2012 ◽  
Vol 498 ◽  
pp. 187-198 ◽  
Author(s):  
Adriana Sandu ◽  
Marin Sandu ◽  
Dan Mihai Constantinescu
Keyword(s):  
Load Capacity ◽  
Numerical Approach ◽  
Nonlinear Finite Element ◽  
Geometrical Parameters ◽  
Bonded Joints ◽  
Adhesively Bonded ◽  
Adhesively Bonded Joints ◽  
Nonlinear Approach ◽  
Stress States ◽  
Analytical Relations

In this paper, starting from analytic relations presented in literature, a more general approach was obtained in order to evaluate the load capacity of single strapped joints in the cases when the adherends are right or tapered in the overlap zone. Two distinct loading cases, in tension and in bending, are considered. The analytical relations were validated by nonlinear finite element analyses. The comparison with the similar results of the linear analyses emphasized that only the nonlinear approach is appropriate to study the stress states in unsymmetrical joints, even if the adhesive can be considered as an isotropic and homogenous material. For design purposes, the influence of some geometrical parameters on the stress state in the joint was also evaluated.

scholarly journals Designing the Hotspots Distribution by Anisotropic Growth

Molecules ◽  
2021 ◽  
Vol 26 (1) ◽  
pp. 187
Author(s):  
Tianshun Li ◽  
Renxian Gao ◽  
Xiaolong Zhang ◽  
Yongjun Zhang
Keyword(s):  
Au Nanoparticles ◽  
Fdtd Method ◽  
Polarization Dependence ◽  
Noble Metal Nanoparticles ◽  
Oblique Angle Deposition ◽  
Matlab Simulation ◽  
Different Shapes ◽  
Plasma Enhancement ◽  
Difference Time ◽  
Good Agreement

Changing the morphology of noble metal nanoparticles and polarization dependence of nanoparticles with different morphologies is an important part of further research on surface plasma enhancement. Therefore, we used the method based on Matlab simulation to provide a simple and effective method for preparing the morphologies of Au nanoparticles with different morphologies, and prepared the structure of Au nanoparticles with good uniformity and different morphologies by oblique angle deposition (OAD) technology. The change of the surface morphology of nanoparticles from spherical to square to diamond can be effectively controlled by changing the deposition angle. The finite difference time domain (FDTD) method was used to simulate the electromagnetic fields of Au nanoparticles with different morphologies to explore the polarization dependence of nanoparticles with different shapes, which was in good agreement with Raman spectrum.

Biaxial Strength of HY 80 Steel

1985 ◽  
Vol 107 (2) ◽  
pp. 132-137 ◽  
Author(s):  
K. S. Chan ◽  
U. S. Lindholm ◽  
J. Wise
Keyword(s):  
Biaxial Tension ◽  
Strain Ratio ◽  
Thin Wall ◽  
Plastic Strain Ratio ◽  
Axial Tension ◽  
Diffuse Necking ◽  
Stress States ◽  
Von Mises ◽  
Tube Geometry ◽  
Good Agreement

The biaxial deformation behavior of HY 80 steel has been examined by testing thin wall tubes under combined axial tension and internal pressure. The effective stress-strain curves and the hardening response have been found to vary with the stress state. The plastic strain ratio at a given stress ratio deviates from the von Mises value except at the stress states near uniaxial tension, plane strain and equi-biaxial tension. Using Drucker theory, these deviations are eliminated and the resulting yield locus is in good agreement with both the Bishop-Hill theory and the experimental results. Influenced by the tube geometry, the instability strains at the onset of diffuse necking are decreased by an increase in hoop tension. The diffuse necking strains are reasonably predicted by the Swift and the Lankford-Saibel/Mellor criteria.

The Additive Nature of Film Cooling From Rows of Holes

1976 ◽  
Vol 98 (4) ◽  
pp. 457-463 ◽  
Author(s):  
J. F. Muska ◽  
R. W. Fish ◽  
M. Suo
Keyword(s):  
Film Cooling ◽  
Cumulative Effect ◽  
Multiple Injection ◽  
Flat Plates ◽  
Upstream Station ◽  
Good Agreement

A method of superposition which predicts the cumulative effect of film cooling has been described in the literature by Sellers. This method predicts the magnitude and extent of film cooling downstream of multiple injection stations by accounting for the effectiveness level from each upstream station individually. Sellers compared the method with results from multiple slots and good agreement was demonstrated. Because of the simplicity of the method it was proposed as a method to predict the cumulative effect of film cooling from rows of holes. To substantiate this, experiments were conducted with film cooling schemes on flat plates and airfoils. The results of these experiments demonstrate that the method is satisfactory for design of film cooled airfoils in the required range of geometries and coolant flows.

scholarly journals Hysteretic Behavior of Geopolymer Concrete with Active Confinement Subjected to Monotonic and Cyclic Axial Compression: An Experimental Study

Materials ◽  
2020 ◽  
Vol 13 (18) ◽  
pp. 3997 ◽  
Author(s):  
Huailiang Wang ◽  
Yuhui Wu ◽  
Min Wei ◽  
Lang Wang ◽  
Baoquan Cheng
Keyword(s):  
Failure Modes ◽  
Peak Stress ◽  
Hysteretic Behavior ◽  
Stress And Strain ◽  
Geopolymer Concrete ◽  
Cement Concrete ◽  
Cyclic Compression ◽  
Stress States ◽  
Loading Modes ◽  
Good Agreement

This paper investigated the performance of actively confined geopolymer concrete (GPC) through experiments. The mechanical properties of GPC under triaxial stress states were analyzed and discussed from the prospects of failure modes, axial peak stress and strain, monotonic and cyclic constitutive relationships. The experimental results demonstrated that the loading modes (monotonic loading and cyclic loading) had little effect on the failure mode and axial peak stress and strain. The improvement of the strength and ductility of GPC with the increase in confinement level was consistent with that of the conventional cement concrete while the strain enhancement of confined GPC was lower than that of confined conventional cement concrete at the same confinement level. The curves of the monotonic stress–strain and the envelop of cyclic compression were predicted through Mander’s model with good accuracy. The unloading/reloading models proposed by Lokuge were modified and the predicted cyclic hysteresis curves for actively confined GPC were in good agreement with the cyclic compression results. Findings from this study provide references for the application of geopolymer concrete.

scholarly journals Temperature Robust PCA Based Stress Monitoring Approach

2016 ◽  
Vol 713 ◽  
pp. 288-292 ◽  
Author(s):  
Jabid Quiroga ◽  
John Quiroga ◽  
Luis Mujica ◽  
Rodolfo Villamizar ◽  
Magda Ruiz
Keyword(s):  
Statistical Model ◽  
Numerical Simulations ◽  
Environmental Conditions ◽  
Guided Wave ◽  
Stress Monitoring ◽  
Robust Pca ◽  
Different Temperatures ◽  
Stress States ◽  
Good Agreement

In this paper, a guided wave temperature robust PCA-based stress monitoring methodology is proposed. It is based on the analysis of the longitudinal guided wave propagating along the path under stress. Slight changes in the wave are detected by means of PCA via statistical T2 and Q indices. Experimental and numerical simulations of the guided wave propagating in material under different temperatures have shown significant variations in the amplitude and the velocity of the wave. This condition can jeopardize the discrimination of the different stress scenarios detected by the PCA indices. Thus, it is proposed a methodology based on an extended knowledge base, composed by a PCA statistical model for different discrete temperatures to produce a robust classification of stress states under variable environmental conditions. Experimental results have shown a good agreement between the predicted scenarios and the real ones

Free Vibration Analysis of Symmetric Sandwich Beams

2017 ◽  
Vol 872 ◽  
pp. 399-404
Author(s):  
Zakaria Ibnorachid ◽  
Khalid El Bikri ◽  
Lhoucine Boutahar
Keyword(s):  
Sandwich Beam ◽  
Free Vibration Analysis ◽  
Core Layer ◽  
Equation Of Motion ◽  
Geometrical Parameters ◽  
Symmetric Vibration ◽  
Materials Properties ◽  
The Core ◽  
Validation Of Results ◽  
Good Agreement

The aim of the present work is to study the linear free symmetric vibration of three-layer sandwich beam using the energy method. The zigzag model is used to describe the displacement field. The theoretical model is based on the top and bottom layers behave as Euler-Bernoulli beams while the core layer as a Timoshenko beam. Based on Hamilton’s principle, the governing equation of motion sandwich beam is obtained in order to calculate the linear frequency parameters. Two types of boundary conditions simple supported-simple-supported (SS-SS) and clamped-clamped (C-C) under the influence of materials properties and geometrical parameters are studied. The validation of results is done by comparing with another studies, which available in the literature and found good agreement between the studies.

Experimental and Theoretical Investigation of Performance of a Solar Chimney Model Part II: Model Development and Validation

2021 ◽  
Vol 5 (2) ◽  
Author(s):  
Ibrahim A Abuashe ◽  
Bashir H Arebi ◽  
Essaied M Shuia
Keyword(s):  
Mathematical Model ◽  
Power Output ◽  
Model Development ◽  
Geometrical Parameters ◽  
Balance Equations ◽  
Solar Chimney ◽  
And Performance ◽  
Development And Validation ◽  
The Mathematical Model ◽  
Good Agreement

A mathematical model based on the momentum, continuity and energy balance equations was developed to simulate the behavior of the air flow inside the solar chimney system. The model can estimate the power output and performance of solar chimney systems. The developed mathematical model is validated by the experimental data that were collected from small pilot solar chimney; (experiment was presented in part I). Good agreement was obtained between the experimental results and that from the mathematical model. The model can be used to analyze the solar chimney systems and to determine the effect of geometrical parameters such as chimney height and collector diameter on the power output and the efficiency of the system

scholarly journals Experimental study on the hydraulic capacity of grate inlets with supercritical surface flow conditions

2019 ◽  
Vol 79 (9) ◽  
pp. 1717-1726 ◽  
Author(s):  
Svenja Kemper ◽  
Andreas Schlenkhoff
Keyword(s):  
Numerical Models ◽  
Surface Flow ◽  
Physical Model Test ◽  
Geometrical Parameters ◽  
Flow Conditions ◽  
Rainfall Events ◽  
Real Flow ◽  
Underground System ◽  
Heavy Rainfall Events ◽  
Good Agreement

Abstract Due to an increasing number of heavy rainfall events, the managing of urban flooding requires new design approaches in urban drainage engineering. With bidirectional coupled numerical models the surface runoff, the underground sewer flow and the interaction processes between both systems can be calculated. Most of the numerical models use a weir equation to calculate the surface to sewer flow with unsurcharged flow conditions, but uncertainties still exist in the representation of the real flow conditions. Street inlets, existing in different types, are the connecting elements between the surface and the underground system. In the present study, an empirical formula was developed based on physical model test runs to estimate the hydraulic capacity and type-specific efficiency of grate inlets with supercritical surface flow. Influencing hydraulic parameters are water depth and flow velocity upstream of the grate and, in addition, different geometrical parameters are taken into account, such as the grate dimensions or the orientation of the bars (transverse, longitudinal or diagonal). Good agreement between estimated and measured results could be proven with relative deviations less than 1%.

scholarly journals Design, Synthesis, Spectral and Theoretical Studies of Some Picrates

2019 ◽  
Vol 32 (1) ◽  
pp. 174-182
Author(s):  
S. Amala ◽  
G. Rajarajan ◽  
E. Dhineshkumar ◽  
M. Arockia doss ◽  
V. Thanikachalam
Keyword(s):  
Geometrical Parameters ◽  
Slight Effect ◽  
Design Synthesis ◽  
1H And 13C Nmr ◽  
Visible Spectra ◽  
Ft Ir ◽  
Uv Visible ◽  
Small Change ◽  
Experimental Values ◽  
Good Agreement

The structures of newly synthesized compounds (1-3) viz. 3-ethyl-5-methyl-2,6-bis(4- chlorophenyl)piperidin-1-ium picrate (1), 3-ethyl-5-methyl-2,6-bis(4-methylphenyl)piperidin-1-ium picrate (2) and 3-ethyl-5-methyl-2,6-bis(3,4-dimethoxyphenyl)piperidin-1-ium picrate (3) were confirmed by elemental analysis, FT-IR, 1H and 13C NMR. The UV-visible spectra, fluoresence, emission properties of synthesized 1-3 in different solvents were studied. Compounds 1-3 solvatochromic displays a slight effect of the emission and absorption spectrum, indicating a small change in the dipole moment upon excitation of compounds 1-3. All the compounds were investigated by DFT. The theoretical geometrical parameters are in good agreement with experimental values.

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