The tensile deformation is the most common forming principle in sheet process, but there a new tube process—tube hydro-forging has been developed based on of compression deformation. In addition to instability problem, surface defect—thickness distortion—was found this paper, wall thickness distortion analyzed from point view mechanics and It revealed that low pressure hydroforming bending mome...

in this paper, we study spacelike dual biharmonic curves. we characterize spacelike dual biharmonic curves in terms of their curvature and torsion in the lorentzian dual heisenberg group . we give necessary and sufficient conditions for spacelike dual biharmonic curves in the lorentzian dual heisenberg group . therefore, we prove that all spacelike dual biharmonic curves are spacelike dual heli...

In this paper, we introduce the concept of $g$-dual frames for Hilbert $C^{*}$-modules, and then the properties and stability results of $g$-dual frames  are given.  A characterization of $g$-dual frames, approximately dual frames and dual frames of a given frame is established. We also give some examples to show that the characterization of $g$-dual frames for Riesz bases in Hilbert spaces is ...

in this paper, single, bi-layered and three-layered tube hydroforming processes were numerically simulated using the finite element method. it was found that the final bulges heights resulted from the models were in good agreement with the experimental results. three types of modeling were kept with the same geometry, tube material and process parameters to be compared between the obtained hydr...

In this paper, single, bi-layered and three-layered tube hydroforming processes were numerically simulated using the finite element method. It was found that the final bulges heights resulted from the models were in good agreement with the experimental results. Three types of modeling were kept with the same geometry, tube material and process parameters to be compared between the obtained hydr...

During tube hydroforming process, the friction conditions between and die have a great importance on material plastic flow distribution of residual stresses final component. Indeed, three-dimensional finite element model process in case square section has been performed, using dynamic static approaches, to study effect both induced by process. First, comparative numerical experimental results c...