In this paper, the mechanism of improvement of formability in pulsating hydroforming of T-shape tubes is investigated by the finite element simulation and experiment. It is shown that local thinning was prevented by oscillating the internal pressure, because the protrusion is formed gradually by the prevention of sharp bulging. In the hydroforming, for the pulsating pressure, several steps occu...

In this paper, hydroforming process of bent tubes in T-shaped die is studied for pulsating and linear pressure paths by the finite element method. Forming Limit Diagrams (FLDs) and thickness distribution curves are used to investigate the effect of pulsating pressure on hydroforming process. In addition, the obtained numerical results are compared with experimental results of hydroforming of st...

in this paper, analysis of fluid flow and heat transfer over the bank of tubes is considered. k-ω sst model is applied for simulation of turbulent flow. in this paper, the improvement of efficiency of a bundle of circular tubes by changing the shape of the cross section of one row of the pipes to the elliptical cross section as an innovative plan is considered. as know, friction factor in turbu...

Tube hydroforming (THF) process is used to produce the complex components from the initial cylindrical tubes. In this paper, T- shape component was formed using a tube hydroforming machine and the residual stresses of hydroformed tube was determined by hole drilling method. Subsequently, the thickness distribution and residual stresses of final tube were investigated using experimental and fini...

Crystalline chitosan was successfully prepared from crab tendons with aligned chitin molecules. Chitosan obtained preserved the tube structure with a suitable size for nerve conduits (t-chitosan tube). The chitosan tubes were compounded with hydroxy apatite (HAp) using an alternate soaking method (t-chitosan/HAp tube) to enhance the strength of the tube walls. HAp crystals formed in the walls o...

tube hydroforming (thf) process is used to produce the complex components from the initial cylindrical tubes. in this paper, t- shape component was formed using a tube hydroforming machine and the residual stresses of hydroformed tube was determined by hole drilling method. subsequently, the thickness distribution and residual stresses of final tube were investigated using experimental and fini...

in this paper, convection heat transfer of al2o3-water nanofluid turbulent flow through internally ribbed tubes with different rib shapes (rectangular, trapezoidal and semi-circular) is numerically investigated. for each rib shape, the optimum geometric ratio and volume fraction were calculated using entropy generation minimization technique. the governing equations in steady state and axisymme...

Tube hydroforming (THF) process is used to produce the complex components from the initial cylindrical tubes. In this paper, T- shape component was formed using a tube hydroforming machine and the residual stresses of hydroformed tube was determined by hole drilling method. Subsequently, the thickness distribution and residual stresses of final tube were investigated using experimental and fini...