750 research outputs found
Functional Integral Approach in the Theory of Color Superconductivity
In this series of lectures we present the functional integral method for
studying the superconducting pairing of quarks with the formation of the
diquarks as well as the quark-antiquark pairing in dense QCD. The dynamical
equations for the superconducting order parameters are the nonlinear integral
equations for the composite quantum fields describing the quark-quark or
quark-antiquark systems. These composite fields are the bi-local fields if the
pairing is generated by the gluon exchange while for the instanton induced
pairing interactions they are the local ones. The expressions of the free
energy densities are derived. The binding of three quarks is also discussed.Comment: 21 pages, 2 figures, Lectures at the VIth Vietnam International
School in Theoretical Physics, Vung Tau, 27 December 1999 -- 08 January 200
Monte-Carlo simulation of the durability of glass fibre reinforced composite under environmental stress corrosion
The lifetime distribution of glass fibre subject to permanent environmental stress corrosion is very important for assessing the durability and damage tolerance of composites using glass reinforcement. A mechanical model based on the statistics of flaw spectra during stress corrosion and 3D shear lag model is presented. The proposed approach shows that it is possible to
identify the influence of stress corrosion properties on the long term durability of glass fibre reinforced composites (GFRP)
A smoothed four-node piezoelectric element for analysis of two-dimensional smart structures
This paper reports a study of linear elastic analysis of two-dimensional piezoelectric structures using a smoothed four-node piezoelectric element. The element is built by incorporating the strain smoothing method of mesh-free conforming nodal integration into the standard four-node quadrilateral piezoelectric finite element. The approximations of mechanical strains and electric potential fields are normalized using a constant smoothing function. This allows the field gradients to be directly computed from shape functions. No mapping or coordinate transformation is necessary so that the element can be used in arbitrary shapes. Through several examples, the simplicity, efficiency and reliability of the element are demonstrated. Numerical results and comparative studies with
other existing solutions in the literature suggest that the present element is robust, computationally inexpensive and easy to implement
- …