in this paper, multi-stage optimum design of composite pressure vessels is presented. the design variables for composite vessels include the head shape, the winding angle, the layer thickness, the number of layers, and the stacking sequence. a parameter called modified shape factor is introduced as an objective function. this parameter takes into account the effects of the internal pressure and...

The thermal denaturation (melting) of DNA molecules is a thermodynamic and conformational order-disorder transition from a double-stranded to a single-stranded state. Modeling DNA melting at the atomistic level is severely hampered due to the time and length scales of this transition. We propose a coarse-grained model where DNA strands are represented as oligomer chains of N beads using the sin...

This paper discusses the mechanical design and simulation of a novel omnidirectional wheel based on Reuleaux-triangles. The main feature of our omniwheel is that the point of contact of the wheel with the floor is always kept at the same distance from the center of rotation by mechanical means. This produces smooth translational movement on a flat surface, even when the profile of the complete ...

Bulk phase separation is responsible for the occurrence of stacks of different layers in sedimentation of colloidal mixtures. A recently proposed theory (de las Heras and Schmidt 2013 Soft Matter 9 8636) establishes a unique connection between the bulk phase behaviour and sedimentation-diffusion-equilibrium. The theory constructs a stacking diagram of all possible sequences of stacks under grav...

In this paper, the first and second order approximations of Taylor expansion are used for calculating the change of each natural frequency by modifying an arbitrary parameter of a system with a known amount and based on this approximation, the inverse eigenvalue problem is transformed to a solvable algebraic equation. The finite element formulation, based on the classical laminated plate theory...

in this paper, the finite element analysis of stability problem of vehicle composite drive shafts subjected to torsional loading is studied. first, using the minimum total potential energy principle, the governing equations are derived and then they are solved by finite element method. the initial geometrical imperfection which is usually in the form of radial displacement, is taken into consid...

Most ab initio pseudoknot predicting methods provide very few folding scenarios for a given RNA sequence and have low sensitivities. RNA researchers, in many cases, would rather sacrifice the specificity for a much higher sensitivity for pseudoknot detection. In this study, we introduce the Pseudoknot Local Motif Model and Dynamic Partner Sequence Stacking (PLMM_DPSS) algorithm which predicts a...

(ABSTRACT) Composite panel structure optimization is commonly decomposed into panel optimization subproblems, with specified local loads, resulting in manufacturing incompatibilities between adjacent panel designs. Using genetic algorithms to optimize local panel stacking sequences allows panel populations of stacking sequences to evolve in parallel and send migrants to adjacent panels, so as t...

Low stacking fault energy face centered cubic (FCC) materials contain characteristic defect structures. Stacking fault tetrahedral are one of those rare structures that occur under special experimental conditions. For the first time, stacking fault tetrahedral were observed in Fe-30Mn-3Al-3Si twinning induced plasticity (TWIP) steel. Their presence resulted from a quenching heat treatment.