Stretching process of sheet metals in both cases of axisymmetric and non-axisymmetric is analyzed. A rigid-plastic, normal anisotrop material is assumed and large strain formulation is applied. Triangular elements are used and stiffness equations of elements are obtained from virtual work principle. These nonlinear equations are linearized by Newton-Raphsons method and are solved by Gaussian el...

Abstract Side-notched tube structures made of superelastic material are increasingly being studied in surgical robotics as they can easily be integrated into instruments and offer the surgeon enhanced dexterity. Their simple design ability to achieve large bending angles small radii make them particularly suited for use constrained workspace surgery. Up now, however, no model has been able accu...

introduction dominant process in arid and semi-arid region is dynamic of wind that carries the sand and caused damage to several facilities and human settlements. there are many human settlements with low population and mostly small and scattered in different parts of foothills of dasht-e lut (lut desert), especially in mountainous margins of alluvial fans. residential and cultivation area of t...

Linear systems with structures such as Toeplitz, Vandermonde or Cauchy-likeness can be solved in O (̃α2n) operations, where n is the matrix size, α is its displacement rank, and O ̃ denotes the omission of logarithmic factors. We show that for such matrices, this cost can be reduced to O (̃αω−1n), where ω is a feasible exponent for matrix multiplication over the base field. The best known estimate...