Analytical model for planar tube hydroforming: Prediction of formed shape, corner fill, wall thinning, and forming pressure

2008 ◽  
Vol 50 (8) ◽  
pp. 1263-1279 ◽  
Author(s):  
Chen Yang ◽  
Gracious Ngaile
Keyword(s):  
Analytical Model ◽  
Tube Hydroforming ◽  
Wall Thinning

Comparison of Failure Modes of Piping Systems With Wall Thinning Subjected to In-Plane, Out-of-Plane and Mixed Mode Bending Under Seismic Load: Computational Approach

2007 ◽  
Author(s):  
Satoshi Tsunoi ◽  
Akira Mikami ◽  
Izumi Nakamura ◽  
Akihito Otani ◽  
Masaki Shiratori
Keyword(s):  
Analytical Model ◽  
Failure Modes ◽  
Experimental Investigations ◽  
Seismic Load ◽  
Piping System ◽  
Wall Thinning ◽  
Piping Systems ◽  
Out Of Plane ◽  
Seismic Loadings ◽  
Local Wall Thinning

The authors have proposed an analytical model by which they can simulate the dynamic and failure behaviors of piping systems with local wall thinning against seismic loadings. In the previous paper [13], the authors have carried out a series of experimental investigations about dynamic and failure behaviors of the piping system with fully circumferential 50% wall thinning at an elbow or two elbows. In this paper these experiments have been simulated by using the above proposed analytical model and investigated to what extent they can catch the experimental behaviors by simulations.

The Hydroforming of Micro-Square Tubes With Non-Equal Section and Dendritic Shape

2006 ◽  
Vol 505-507 ◽  
pp. 739-744
Author(s):  
Yuan Chuan Hsu ◽  
Tung Sheng Yang ◽  
J.L. Wu ◽  
Y.X. Chen
Keyword(s):  
Finite Element ◽  
Finite Element Simulation ◽  
Tube Hydroforming ◽  
Simulation Technique ◽  
Hydraulic Pressure ◽  
Micro Forming ◽  
Wall Thinning ◽  
Element Simulation ◽  
Feeding Speed ◽  
Dendritic Shape

Currently, tube hydroforming and metal micro-forming technique have emerged as the attractive and important developing tendencies in industry. Hence, in this study, the finite element simulation technique was employed to investigate the micro-hydroforming for making the micro-square tube with non-equal section and dendritic shape from square tube. Results of the current study show that the deformation of micro-square tube can be effectively analyzed by finite element simulation. The bulging and wall thinning of the tube are severely influenced not only by the internal hydraulic pressure but also by the punch axial feeding speed.

Study of Forming Parameters in Hydroforming of a Thin-Walled ASTM C11000 Copper Tube

2009 ◽  
Vol 83-86 ◽  
pp. 133-142
Author(s):  
S.M.H. Seyedkashi ◽  
Golam Hosein Liaghat ◽  
Hassan Moslemi Naeini ◽  
M. Hoseinpour Gollo
Keyword(s):  
Internal Pressure ◽  
Tube Wall ◽  
Tube Hydroforming ◽  
Contact Friction ◽  
Effective Parameters ◽  
Axial Feeding ◽  
Loading Paths ◽  
Wall Thinning ◽  
Non Linear ◽  
A New Technique

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.

Study of Localized Thinning of Copper Tube Hydroforming in Square Section Die: Effect of Friction Conditions

2015 ◽  
Vol 651-653 ◽  
pp. 65-70 ◽  
Author(s):  
Abir Abdelkefi ◽  
Nathalie Boudeau ◽  
Pierrick Malecot ◽  
Noamen Guermazi ◽  
Gérard Michel
Keyword(s):  
Finite Element ◽  
Friction Coefficient ◽  
Analytical Model ◽  
Thickness Distribution ◽  
Tube Hydroforming ◽  
Analytical Models ◽  
Specific Test ◽  
Good Evaluation ◽  
Shaped Tube ◽  
Tube Expansion

The friction conditions are responsible of the thickness distribution in a part realized by tube hydroforming. Then it is essential to have a good evaluation of the friction coefficient for running predictive finite element simulations. The tube expansion in a square die is one of tests proposed for the friction evaluation. In the literature, several analytical models have been developed for this specific test. The present paper concentrates on one of this model and results obtained from the analytical analysis, FE simulations and experiments are compared. The repartition of the thickness over the shaped tube and its evolution during the process are studied. The tendencies are in agreement but some complementary evaluations are proposed for using the proposed approach for the evaluation of the friction coefficient with the analytical model.

Analytical Model for the Characterization of the Guiding Zone Tribotest for Tube Hydroforming

2009 ◽  
Vol 131 (2) ◽  
Author(s):  
Gracious Ngaile ◽  
Chen Yang
Keyword(s):  
Analytical Model ◽  
Tube Hydroforming ◽  
Closed Form Solution ◽  
Form Solution ◽  
Stress Strain ◽  
Widespread Application ◽  
Part Surface ◽  
Depth Study ◽  
Geometric Variables ◽  
Increasing Demand

Common part failures in tube hydroforming include wrinkling, premature fracture, and unacceptable part surface quality. Some of these failures are attributed to the inability to optimize tribological conditions. There has been an increasing demand for the development of effective lubricants for tube hydroforming due to widespread application of this process. This paper presents an analytical model of the guiding zone tribotest commonly used to evaluate lubricant performance for tube hydroforming. Through a mechanistic approach, a closed-form solution for the field variables contact pressure, effective stress/strain, longitudinal stress/strain, and hoop stress can be computed. The analytical model was validated by the finite element method. In addition to determining friction coefficient, the expression for local state of stress and strain on the tube provides an opportunity for in-depth study of the behavior of lubricant and associated lubrication mechanisms. The model can aid as a quick tool for iterating geometric variables in the design of a guiding zone, which is an integral part of tube hydroforming tooling.

Analytical Model for the Characterization of the Guiding Zone Tribotest for Tube Hydroforming

2008 ◽  
Author(s):  
Gracious Ngaile ◽  
Chen Yang
Keyword(s):  
Analytical Model ◽  
Tube Hydroforming ◽  
Closed Form Solution ◽  
Form Solution ◽  
Stress Strain ◽  
Widespread Application ◽  
Part Surface ◽  
Depth Study ◽  
Geometric Variables ◽  
Increasing Demand

Common part failures in tube hydroforming include wrinkling, premature fracture, and unacceptable part surface quality. Some of these failures are attributed to the inability to optimize tribological conditions. There has been an increasing demand for the development of effective lubricants for tube hydroforming, due to widespread application of this process. This paper presents an analytical model of the guiding zone tribotest commonly used to evaluate lubricant performance for tube hydroforming. Through a mechanistic approach, a closed-form solution for the field variables contact pressure, effective stress/strain, longitudinal stress/strain, and hoop stress can be computed. The analytical model was validated by the finite element method. In addition to determining friction coefficient, the expression for local state of stress and strain on the tube provides an opportunity for in-depth study of the behavior of lubricant and associated lubrication mechanisms. The model can aid as a quick tool for iterating geometric variables in the design of a guiding zone, which is an integral part of tube hydroforming tooling.

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