scholarly journals Influence of multiple load indentation on the mechanical and material behaviour of steel cone-cylinder under axial compression

2021 ◽  
Author(s):  
Olawale Ifayefunmi ◽  
Sivakumar D. ◽  
Amir Hafiz Sazali
Keyword(s):  
Test Data ◽  
Good Accuracy ◽  
Cone Angle ◽  
Geometric Parameters ◽  
Collapse Load ◽  
Material Behaviour ◽  
Numerical Studies ◽  
Multiple Load ◽  
Welding Technique ◽  
Load Indentation

Abstract The first set of test data on axial collapse of cone-cylinder assembly having multiple load indentation (MLI) and its accompanying numerical studies is presented in this paper. Two perfect and two imperfect steel cone-cylinders were prepared in pairs. The cone-cylinder models have the following geometric parameters: cone radius of 40 mm, cylinder radius of 70 mm,wall thickness of 0.5 mm and cone angle of 16.7°. Cone and cylinder part were combined using Metal Inert Gas (MIG) welding technique. Results show that the repeatability of the experiment was good (3% for the perfect and 7% for the imperfect). Also, numerical prediction tends to reproduce the test data with good accuracy. The error between both approches ranges from 1% to -8%. Furthermore, the influence of geometric parameters are also significant in determining the collapse load of this type of structure. Finally, the worst multiple load indentation (WMLI) was explored for steel cone-cylinders assembly using different number of load indentations. Results indicate that as the number of indents increases, the sensitivity of the cone-cylinder models to imperfection also increases. However, at different imperfection amplitude, A, two regions were observed; (i) the region where cone-cylinder with N = 8 is more sensitive (A < 1.5), and (ii) the region where N = 4 produce the worst imperfection (1.5 < A ≤ 1.68).

scholarly journals Numerical and experimental study of the fundamental flow characteristics of a 3D gully box under drainage

2017 ◽  
Vol 75 (9) ◽  
pp. 2204-2215 ◽  
Author(s):  
Pedro Lopes ◽  
Rita F. Carvalho ◽  
Jorge Leandro
Keyword(s):  
Turbulence Model ◽  
Slip Velocity ◽  
Source Term ◽  
Good Accuracy ◽  
Flow Characteristics ◽  
Air Entrainment ◽  
Free Surface Elevation ◽  
Discharge Coefficients ◽  
Numerical Studies ◽  
Entrapped Air

Numerical studies regarding the influence of entrapped air on the hydraulic performance of gullies are nonexistent. This is due to the lack of a model that simulates the air-entrainment phenomena and consequently the entrapped air. In this work, we used experimental data to validate an air-entrainment model that uses a Volume-of-Fluid based method to detect the interface and the Shear-stress transport k-ω turbulence model. The air is detected in a sub-grid scale, generated by a source term and transported using a slip velocity formulation. Results are shown in terms of free-surface elevation, velocity profiles, turbulent kinetic energy and discharge coefficients. The air-entrainment model allied to the turbulence model showed a good accuracy in the prediction of the zones of the gully where the air is more concentrated.

Applicability of Net-Section Collapse Load Approach to Maximum Load Predictions of Multiple Circumferential Cracked Pipes: Numerical Study

2015 ◽  
Author(s):  
Myeong-Woo Lee ◽  
Seung-Jae Kim ◽  
So-Dam Lee ◽  
Jun-Young Jeon ◽  
Yun-Jae Kim
Keyword(s):  
Experimental Data ◽  
Numerical Method ◽  
Test Data ◽  
Numerical Study ◽  
Maximum Load ◽  
Load Carrying Capacity ◽  
Collapse Load ◽  
Crack Geometry ◽  
Large Sets ◽  
Load Carrying

To estimate maximum load-carrying capacity of pipes with multiple circumferential cracks, the net-section collapse load approach has been proposed. Although the proposed method has been validated against pipe test data, experimental data are quite limited due to large sets of variables to be considered. In this paper, a numerical method is proposed to generate virtual pipe test data with wide ranges of crack geometry and interspacing. To get confidence of the proposed numerical method, it is firstly applied to simulate existing 4-inch diameter schedule 80 pipes with two circumferential cracks. Predicted maximum loads agree well with experimental data. Then the proposed method is applied to generate maximum loads for wider ranges of crack geometry and loading conditions. It is found that the net-section collapse load approach works well for all cases considered.

scholarly journals ACCELERATION OF ELECTRON BUNCHES USING PERIODIC DIELECTRIC STRUCTURES WITH AND WITHOUT COATING

2021 ◽  
pp. 60-64
Author(s):  
A.V. Vasyliev ◽  
A.O. Bolshov ◽  
K.V. Galaydych ◽  
A.I. Povrozin ◽  
G.V. Sotnikov
Keyword(s):  
Laser Excitation ◽  
Geometric Parameters ◽  
Gold Coating ◽  
Electron Bunches ◽  
Numerical Studies ◽  
High Acceleration ◽  
On Chip ◽  
Laser Accelerators ◽  
Dielectric Structures

The numerical studies of high acceleration gradients obtaining for the dielectric laser accelerators (DLA) based on-chip structures with one-sided laser excitation at a wavelength of 800 nm are presented. The electron flight heights of 200 and 400 nm over a structure are presented. The influence of the geometric parameters of the structures on the acceleration gradients was also investigated. A study of changes in the acceleration gradients of structures, when applying a gold coating on these types of structures, has been carried out.

Impact of Geometric Parameters of Capillary Design on Quality of Gold Ball Bonding

2006 ◽  
Vol 3 (2) ◽  
pp. 73-85
Author(s):  
Jerry Chih-Tsong Su ◽  
Cheng-Hsiang Yu
Keyword(s):  
Integrated Circuits ◽  
Shear Force ◽  
Process Development ◽  
Cone Angle ◽  
Geometric Parameters ◽  
Bond Quality ◽  
Bonding Quality ◽  
Ball Shear ◽  
Ball Size ◽  
Gold Ball

0.13μm or smaller critical dimension of integrated circuits has driven the bonding pad pitch down to 50μm or even smaller. It has also had quite an impact on the adhesive force between the bonding pad and the gold ball. This study focuses on the correlation between the capillary geometric parameters (i.e. tip diameter, chamfer diameter, inner chamfer angle, and cone angle) and the bonding quality (i.e. ball size, ball thickness, ball shear force, specific ball shear force, and capillary vibration). An experimental design is utilized and the response is analyzed statistically. The results show that as the tip diameter and ball size increase, the ball thickness decreases, and the ball shear force increases first and then decreases afterward. As the cone angle decreases, the ball size increases, the ball thickness decreases, and the ball shear force increases. Therefore, both tip diameter and cone angle are significant factors that affect the bond quality. The empirical model, i.e. the correlation between the capillary geometric parameters and the bonding quality is also derived, and is quite useful in predicting the bonding pad size or bonding pad pitch required during process development. The predicted values and the experimental results are shown to have good agreement.

Optimization of a High Pressure Swirl Injector by Using Volume-of-Fluid (VOF) Method

2010 ◽  
Author(s):  
Mohammad Rezaeimoghaddam ◽  
Hossein Moin ◽  
M. R. Modarres Razavi ◽  
Mohammad Pasandideh-Fard ◽  
Rasool Elahi
Keyword(s):  
High Pressure ◽  
Stokes Equations ◽  
Cone Angle ◽  
Volume Of Fluid ◽  
Liquid Sheet ◽  
Vof Method ◽  
Geometric Parameters ◽  
Orifice Diameter ◽  
Swirl Chamber ◽  
Pressure Swirl

In this paper, the effects of various geometric parameters of a high pressure swirl Gasoline Direct Injector (GDI) on the injection flow quality are investigated. The two-dimensional axisymmetric Navier-Stokes equations coupled with the Volume-of-Fluid (VOF) method were employed for simulation of the formation mechanism of the liquid film inside the swirl chamber and the orifice hole of the pressure swirl atomizer. To validate the model, results for base injector were compared in the steady state operation with those of available experiments in the literature. Good agreements were obtained for discharge coefficient (Cd) and cone angle (θ) with experimental data. The effects of five characteristic geometric parameters of swirl injectors such as orifice ratio (orifice length to orifice diameter), angle of swirl chamber, orifice diameter, needle lift and needle head angle (assumed to be cone) were investigated. The results show that increasing the swirl chamber angle leads to an increase in mass flow rate and a decrease of the cone angle of liquid sheet. Through extensive simulations, geometric parameters of an optimum injector were obtained.

Simulation of Static Test of Air-Spring

2006 ◽  
Vol 11-12 ◽  
pp. 713-716 ◽  
Author(s):  
Feng Xiang Li ◽  
Wei Min Yang ◽  
Yu Mei Ding
Keyword(s):  
Test Data ◽  
Parameter Method ◽  
Load Step ◽  
Air Spring ◽  
Static Test ◽  
Remarkable Effect ◽  
Inner Pressure ◽  
In The Beginning ◽  
Multiple Load ◽  
Pressure Output

A method for testing an air-spring was advanced in the beginning. Then ANSYS was utilized to simulate the static test. In the simulation, multiple load steps solution was carried out through APDL *DO-LOOP and array parameter method. Scalar parameter PRESSURE was established as inner pressure tracking parameter to update inner pressure. Table parameter PRESSURES was established as inner pressure output parameter to export inner pressure of each load step. Comparison was done between simulation result and test data to prove the feasibility of simulation. Finally, some major parameters such as cord angle and initial inner pressure were taken into account, which had remarkable effect on the air-spring’s performance.

Applicability of Net-Section Collapse Load Approach to Multiple-Cracked Pipe Assessment: Numerical Study

2017 ◽  
Vol 139 (4) ◽  
Author(s):  
Myeong-Woo Lee ◽  
So-Dam Lee ◽  
Yun-Jae Kim
Keyword(s):  
Finite Element ◽  
Test Data ◽  
Parametric Study ◽  
Fracture Strain ◽  
Numerical Study ◽  
Damage Analysis ◽  
Collapse Load ◽  
Fracture Test ◽  
Strain Model

In this paper, applicability of net-section collapse load approach to circumferential multiple-cracked pipe assessment is investigated using finite element (FE) damage analysis. The FE damage analysis based on the stress-modified fracture strain model is validated against limited fracture test data of two circumferential surface-cracked pipes. Then, the systematic parametric study is performed using the FE damage analysis for symmetrical and asymmetrical surface-cracked pipes. It is found that predictions using the net-section collapse load approach tend to be more accurate with increasing the distance between two symmetrical cracks. For asymmetrical cracks, it is found that the deeper crack plays a more important role and that the existing net-section collapse load expression can be potentially nonconservative. Idealization to symmetrical cracks based on the deeper crack is proposed.

Static Strenght of Doubler Plate Reinforced Tubular K-Joints under Bending Load

2012 ◽  
Vol 166-169 ◽  
pp. 645-648
Author(s):  
Wei Ning Sui ◽  
Xin Long Zhang ◽  
Guo Chang Li ◽  
Xue Bai
Keyword(s):  
Ultimate Strength ◽  
Static Strength ◽  
Geometric Parameters ◽  
Hollow Section ◽  
Numerical Studies ◽  
Bending Load ◽  
Circular Hollow Section

Abstract: In order to study static strength of doubler plate reinforced circular hollow section (CHS) K-joints, experimental and numerical studies conducted by the authors. The effects of parameters Δ (the ratio between the length of doubler plate and the diameter of the brace) and α (the width of the doubler plate) on CHS K-joints subjected to bending load have been investigated and reported by the authors. It is found that the ultimate strength of a CHS K-joints reinforced with appropriately proportioned doubler plates can be up to 2 ratio to its un-reinforced counterpart. Reasonable geometric parameters of the doubler plate can make the chord, brace and doubler plate work together to bear the external bending load. The width and length parameter of the doubler plate, however, have no effect on the stiffness of the reinforced K-joints.

trans-Dichlorobis(tri-m-tolylphosphine)palladium(II)

2006 ◽  
Vol 62 (7) ◽  
pp. m1603-m1605 ◽  
Author(s):  
Reinout Meijboom ◽  
Alfred Muller ◽  
Andreas Roodt
Keyword(s):  
Title Compound ◽  
Cone Angle ◽  
Geometric Parameters ◽  
Planar Geometry ◽  
Square Planar ◽  
Effective Cone

In the title compound, trans-[PdCl2{P(C7H7)3}2], where P(C7H7)3 is tri-m-tolylphosphine, the Pd atom is on an inversion centre, resulting in a trans-square-planar geometry. Selected geometric parameters are Pd—P and Pd—Cl distances of 2.3289 (4) and 2.2897 (4) Å, respectively, and a P—Pd—Cl angle of 87.77 (2)°. The effective cone angle for the tri-m-tolylphosphine is calculated to be 165°.

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