Most models of blown film extrusion are based on thin shell theory, which was first applied to these processes by Pearson and Petrie. There has been some contention in the literature as to the suitability of the thin shell model. More recently, Liu and coworkers presented an alternative quasi-cylindrical model that neglects longitudinal curvature but was reported to agree more closely with expe...

We present a novel framework for the efficient simulation and animation of discrete thin shells. Our method takes a point sampled surface as input and performs all necessary computations without intermediate triangulation. We discretize the thin shell functional using so-called fibers. Such fibers are locally embedded parametric curves crisscrossing individual point samples. In combination, the...

The first step in walnut breeding programs is to identify and evaluate superior genotypes of fruit trees. Hence, there are various walnut breeding programs in various areas of Iran. A study aimed to evaluate the morphological and chemical characteristics of selected superior genotypes of walnut was conducted in the Shahroud region in 2011-2012.  The following genotypes were selected in this stu...

the first step in walnut breeding programs is to identify and evaluate superior genotypes of fruit trees. hence, there are various walnut breeding programs in various areas of iran. a study aimed to evaluate the morphological and chemical characteristics of selected superior genotypes of walnut was conducted in the shahroud region in 2011-2012.  the following genotypes were selected in this stu...

This paper describes single point micro incremental forming (SPMIF) applied to the fabrication of meso-scale shell structures. The authors have developed SPMIF without using any die and backing plate for flexible micro forming of miniature 3D products in a range of micro meters to sub-millimeters. A desk-top type of CNC milling machine was constructed as an experimental apparatus. Thin aluminum...

Micrometer-sized, monodisperse polystyrene (PS)/poly(styrene-co-sodium styrene sulfonate) (P(S-NaSS))/poly(n-butyl methacrylate) (Pn-BMA) composite particles having a ‘golf ball-like’ shape were prepared by seeded dispersion polymerization of n-butyl methacrylate with PS-core/P(S-NaSS)-shell seed particles with various shell thicknesses in the presence of dodecane droplets in a methanol/water (...

We investigate spin polarized electron transport in ultra-thin Si-Core/Ge-Shell and GeCore/Si-Shell nanowire system using semi-classical Monte Carlo simulation method. Depolarization of electron’s spin occurs in nanowire mainly due to D’yakonov-Perel dephasing (DP-mechanism) and Elliott-Yafet dephasing (EY-mechanism). We studied the dependence of spin dephasing on ultra-thin silicon core diamet...

The thermomechanical buckling of simply supported thin shallow spherical shells made of functionally graded material is presented in this paper. A metal-ceramic functionally graded shell with a power law distribution for volume fraction is considered, where its properties vary gradually through the shell thickness direction from pure metal on the inner surface to pure ceramic on the outer surfa...

One of the common failure modes of thin cylindrical shell subjected external pressure is buckling. The buckling pressure of these shell structures are dominantly affected by the geometrical imperfections present in the cylindrical shell which are very difficult to alleviate during manufacturing process. In this work, only three types of geometrical imperfection patterns are considered namely (a...

Numerically accurate simulation of the mechanical behavior of thin flexible structures is important in application areas ranging from engineering design to animation special effects. Subdivision surfaces provide a unique opportunity to integrate geometric modeling with concurrent finite element analysis of thin flexible structures. Their mechanics are governed by the so-called thin-shell equati...