scholarly journals Numerical Study of Tube Hydroforming Process Using Conical Dies

2021 ◽  
Vol 28 (4) ◽  
pp. 25-36
Author(s):  
Tahseen T. Othman Al-Qahwaji ◽  
Ahmad Ameen Hussain

   In this paper the effect of die angle, fluid pressure and axial force on loading paths were studied. In order to reduce the cost and time for the experimental work, ANSYS program is used for implementing the Finite Element Method (FEM), to get optimized loading paths to form a tube using double – cones shape die. Three double die angles θ (116˚ 126˚, 136˚), with three different values of tube outer diametres (40, 45, 50) mm were used. The tube length L_o and thickness t_o for all samples were 80 mm and 2 mm respectively.    The most important results and conclusions that have been reached that had the highest wall thinning percentage of 26.8% with less corner filling is at tube diameter 40 mm and cone angle of (116^°) at forming pressure of 43 MPa with axial feeding 10 mm. However, the lowest wall thinning percentage was 6.9% with best corner filling at diameter 50 mm and cone were angle of (136^°) and forming pressure of 30 MPa with axial feeding 4.5 mm. Two wrinkles constituted during the initial stages of forming the tube with initial diameter of 40 mm where the ratio  d⁄(t=20)   (thick-walled tubes) for all die angles, while only one wrinkle is formed at the center for tubes diameter 45 and 50 mm (thin-walled tubes) . The difference in the location and number of wrinkles at the first stage of formation depends on the loading paths that has been chosen for each process, which was at the diameter 45 and 50 mm towards thin-wall cylinder deformation mode was uniaxial tension. The maximum wall thinning percentage was at the bulge apex for tube diameter 40 mm. But, the maximum wall thinning for tubes of diameters 45 and 50 mm was found at the two sides of the bulge apex .

2009 ◽  
Vol 83-86 ◽  
pp. 133-142
Author(s):  
S.M.H. Seyedkashi ◽  
Golam Hosein Liaghat ◽  
Hassan Moslemi Naeini ◽  
M. Hoseinpour Gollo

Tube hydroforming technology is still considered a new technique growing fast in automotive and aircraft industries. Many researches on all aspects of this process are still required. Contact friction is one of the most effective parameters on tube wall thinning. To successfully fulfill the process without any common defects, it is very important to determine the proper internal pressure and axial feeding loading paths. In this paper, the effect of lubrication on tube wall thinning on ASTM C11000 copper alloy is discussed as well as the effect of internal pressure and axial feeding. An axisymmetric bulged tube is investigated using theoretical, numerical and experimental methods. Improved linear and non-linear pressure and feeding loading paths are applied and the predicted results are experimentally proved. It is observed that non-linear pressure application gives smoother results. Also proper lubrication plays an important role in success of the process.


Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 162
Author(s):  
A.A. Jameei ◽  
S. Pietruszczak

This paper provides a mathematical description of hydromechanical coupling associated with propagation of localized damage. The framework incorporates an embedded discontinuity approach and addresses the assessment of both hydraulic and mechanical properties in the region intercepted by a fracture. Within this approach, an internal length scale parameter is explicitly employed in the definition of equivalent permeability as well as the tangential stiffness operators. The effect of the progressive evolution of damage on the hydro-mechanical coupling is examined and an evolution law is derived governing the variation of equivalent permeability with the continuing deformation. The framework is verified by a numerical study involving 3D simulation of an axial splitting test carried out on a saturated sample under displacement and fluid pressure-controlled conditions. The finite element analysis incorporates the Polynomial-Pressure-Projection (PPP) stabilization technique and a fully implicit time integration scheme.


2020 ◽  
Vol 12 (5) ◽  
pp. 168781402092413
Author(s):  
Lai Hu ◽  
Jun Zha ◽  
Yaolong Chen

This study conducted an investigation on transverse quasi-static three-point loading on a circular aluminum tube and its characteristic plastic failure and energy-absorption behaviors. The thin wall thickness of the aluminum tube, the various diameter and thickness ratios ( D/ t) of the tube, and the tube length are important control parameters. Experimental data for different span length and thickness ratios of the tube were characterized and correlated to its plastic collapse behavior. A simulation model by computational analysis using ANSYS was also conducted as a comparative study. The results of the study found that transverse three-point bend loading (ASTM F290) of a circular aluminum tube underwent different stages of deformation, from initial pure crumpling to crumpling and bending, and finally, structural rupture. The results of master curve analysis found that regions of high energy absorption and low energy absorption can be classified with respect to the characteristic tubular deformation. High energy absorption deformation is correlated with a short span length and higher D/ t ratio, and vice versa for low energy absorption deformation of the circular aluminum tube. Simulation analysis also predicted similar characteristic trends of deformation behavior in the experiment, with a less than 3% average coefficient of variation.


2007 ◽  
Vol 44 (3) ◽  
pp. 314-325 ◽  
Author(s):  
M F Nixon ◽  
J LH Grozic

Gas hydrates are icelike compounds composed of water and methane gas in very compact form. There is substantial evidence from case histories that links gas hydrate dissociation to submarine slope failures and other geohazards. Theoretical analyses have also shown that upon dissociation gas hydrates will cause an increase in fluid pressure and a reduction in effective stress and thus result in loss of the soil strength. This paper presents a preliminary quantification of the effects of gas hydrate dissociation through development of a pore-pressure model that was incorporated into one- and two-dimensional slope stability analyses. The ensuing numerical study investigated submarine slope stability through parametric studies and application to two important case histories and found that dissociation of even small amounts of hydrate can have a significant destabilizing effect. Yet whether gas hydrate dissociation can alone cause large-scale slope failures has still to be demonstrated as there are often many destabilizing processes; however, this research highlights the importance of assessing the effects of gas hydrate dissociation on the behaviour of submarine slopes.Key words: gas hydrates, slope stability, marine, offshore, methane gas, instability.


2018 ◽  
Vol 26 (03) ◽  
pp. 1850027 ◽  
Author(s):  
Pravin Jadhav ◽  
Neeraj Agrawal

This paper presents a numerical study on an adiabatic helical capillary tube employing homogenous and choked flow conditions of a CO2 transcritical system. The theoretical model is based on the fundamental principle of fluid dynamics and thermodynamics. The result of the present model validates with the previously published data. The influence of operating and geometric parameters on the performance of the capillary tube has been evaluated. Flow characterizations of choked and unchoked flow conditions are determined. As the evaporator pressure drops, from unchoked condition to choked state, the percentage change in mass flow rate is minimal. A simulation graph is developed which has been helpful for the design of the helical capillary tube. The choked flow condition in a capillary tube is avoided by either increasing tube diameter of the fixed length tube or decreasing the length of the fixed tube diameter.


2011 ◽  
Vol 51 (1) ◽  
pp. 479 ◽  
Author(s):  
Amin Nabipour ◽  
Brian Evans ◽  
Mohammad Sarmadivaleh

Hydraulic fracturing is known as one of the most common stimulation techniques performed in oil and gas wells for maximising hydrocarbon production. It is a complex procedure due to numerous influencing factors associated with it. As a result, hydraulic fracturing monitoring techniques are used to determine the real-time extent of the induced fracture and to prevent unwanted events. Although the well-known method of monitoring is the microseismic method, active monitoring of a hydraulic fracture has shown capable of providing useful information about the fracture properties in both laboratory conditions and field operations. In this study, the focus is on laboratory experiment of hydraulic fracturing using a true-triaxial cell capable of simulating field conditions required for hydraulic fracturing. By injecting high-pressure fluid, a hydraulic fracture was induced inside a 20 cm cube of cement. Using a pair of ultrasonic transducers, transmission data were recorded before and during the test. Both cases of an open and closed hydraulic fracture were investigated. Then, using a discrete particle scheme, seismic monitoring of the hydraulic fracture was numerically modelled for a hexagonally packed sample and compared with the lab results. The results show good agreements with data in the literature. As the hydraulic fracture crosses the transducers line, signal dispersion was observed in the compressional wave data. A decrease was observed in both the amplitude and velocity of the waves. This can be used as an indicator of the hydraulic fracture width. As the fracture closes by reducing fluid pressure, a sensible increase occurred in the amplitude of the transmitted waves while the travel time showed no detectable variations. The numerical model produced similar results. As the modelled hydraulic fracture reached the source-receiver line, both amplitude and velocity of the transmitted waves decreased. This provides hope for the future real-time ability to monitor the growth of induced fractures during the fraccing operation. At present, however, it still needs improvements to be calibrated with experimental results.


Author(s):  
A. Rasteh ◽  
A. Farokhipour ◽  
M. A. Rasoulian ◽  
Z. Mansoori ◽  
M. Saffar-Avval ◽  
...  

Abstract Fracking (fracturing) is of great importance for enhancing oil and gas production from low permeability reservoirs. Since in fracking fluid, suspension of sand particles are used, the erosion failure of fracturing equipment has become an increasing concern. Accordingly, investigation of erosion of commonly used fittings such as ball seats in order to decrease its adverse consequences has attracted considerable attentions. Although the erosion wear of gas-solid flows in the pipe sudden expansion was investigated in the literature, the effect of particle size, ball seat shape and the contraction configurations on the erosion-induced wear is not fully understood. This study is aimed to explore the most erosion-resistant configuration of a ball seat under various operational conditions. A CFD model is used and a wide range of geometries are investigated. The studied configurations are categorized in three main groups including single cone, double cone and curved cone. In each category, different cone angles and curve styles are considered. The results showed that, among the single cone ball seats, the cone angle of 15° is the most erosion-resistant configuration. It was also shown that the third-order curve style cone has the best erosion performance.


2020 ◽  
Vol 39 (17-18) ◽  
pp. 679-699
Author(s):  
Ruben AJ Weerts ◽  
Olivier Cousigné ◽  
Klaas Kunze ◽  
Marc GD Geers ◽  
Joris JC Remmers

In order to unravel the damage mechanisms occurring in composite-overwrapped pressure vessels (COPVs) subjected to crash conditions, a combined experimental-numerical study has been performed. For the purpose of generality and simplicity, quasi-static contacts on filament-wound cylinders are considered in this paper, as a precursor for geometrically complex impacts on COPVs. Rings with different wall thicknesses are tested to assess how failure mechanisms change when transitioning from thin-wall to thick-wall cylinders. The experimental results are used to identify, which mechanisms occur, and the numerical model is subsequently exploited to analyze the corresponding mechanisms. Based on the understanding of the mechanisms, a method to improve the damage tolerance of thick cylinders is presented. The rings are locally pre-delaminated during manufacturing to promote the growth of these pre-delaminations instead of the initiation of fiber failure.


2019 ◽  
Vol 18 (2) ◽  
pp. 13
Author(s):  
F. P. Branco ◽  
E. D. Buchelt ◽  
F. M. Barbosa ◽  
B. P. Rosa ◽  
D. J. Laporte

Vortex tube is a thermodynamic device, with no moving parts, applied to separate hot and cold air from compressed air injected into the tube. It has many applications in the industry, for example, among others, it can be mentioned electronic systems cooling, machining processes cooling and environmental chambers. This paper presents the design and tube dimensioning based on parameters and data found in the literature. Therefore, a prototype has been made and tested, which allowed the understanding of the influence of internal tube diameter and width on the hot and cold air temperatures while submitted to compressed air with pressure varying from 1 to 2.5bar. Results of tested configurations indicates that the relation between tube length and diameter (L/D) has small influence on vertex tube behavior, meanwhile, 3/8” tube diameter shows lowest temperatures on cold flow (-6.5°C, -8.0°C and -8.5°C) and higher COP (≈ 0.15).


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