R-curve evaluation of pipeline girth welds using advanced measurement techniques

A strain-based flaw assessment procedure is recommended for girth welded pipelines subjected to large deformations. To evaluate the allowable defect dimensions, the tearing resistance needs to be characterized. This paper investigates the effect of weld metal strength mismatch on the resistance curve using Single Edge Notched Tension (SENT) specimens. Several advanced measurement techniques are applied during the tests in order to obtain a continuous measurement of crack extension and to visualize the deformation fields near the crack. The resistance curves are determined using a single specimen technique. The unloading compliance method and the potential drop method result in similar predictions of ductile crack extension, yielding similar resistance curves. Next to these measurements, the full field deformations are determined using digital image correlation. The experiments indicate that the position of the applied notch in the weld has the potential to influence the strain fields

Asymptotic expansions for Laguerre-like orthogonal polynomials

AbstractAsymptotic expansion for the Laguerre polynomials and for their associated functions is extended to the case of a weight function which is the product of the Laguerre weight function by a polynomial, nonnegative on the interval [0,∞[

Matrix interpretation of multiple orthogonality

In this work we give an interpretation of a (s(d + 1) + 1)-term recurrence relation in terms of type II multiple orthogonal polynomials.We rewrite this recurrence relation in matrix form and we obtain a three-term recurrence relation for vector polynomials with matrix coefficients. We present a matrix interpretation of the type II multi-orthogonality conditions.We state a Favard type theorem and the expression for the resolvent function associated to the vector of linear functionals. Finally a reinterpretation of the type II Hermite- Padé approximation in matrix form is given

ENTRAP and its potential interaction with European networks

AbstractENTRAP comprises a pan-European cooperation of leading scientific institutions and regulatory bodies in the field of nuclear-waste characterization and its quality assurance for the safe disposal of radioactive waste. Here, the scope of this cooperation is presented and explained and links or interfaces for a potential collaboration with partners fulfilling tasks of IDG-TP are pursued

Central factorials under the Kontorovich-Lebedev transform of polynomials

We show that slight modifications of the Kontorovich-Lebedev transform lead to an automorphism of the vector space of polynomials. This circumstance along with the Mellin transformation property of the modified Bessel functions perform the passage of monomials to central factorial polynomials. A special attention is driven to the polynomial sequences whose KL-transform is the canonical sequence, which will be fully characterized. Finally, new identities between the central factorials and the Euler polynomials are found.Comment: also available at http://cmup.fc.up.pt/cmup/ since the 2nd August 201

Recurrence Relations In The Table Of Vector Orthogonal Polynomials

. Vector orthogonal polynomials appeared as the denominators of vector approximants ([2]). To compute these last ones or to study the orthogonality itself, it is useful to be able to move in the table of the polynomials. It is obviously the first step before studying non regular cases of vector-orthogonality. 1. Introduction If f 1 ; : : : ; f d are d functions, holomorphic in a neighbourhood of zero, a vector linear functional \Gamma, i.e. defined from I C[[X]] to I C d , can be defined f ff (t) = X i0 c ff i t i ; \Gamma i = (c 1 i ; : : : ; c d i ) t I F (t) = X i0 \Gamma i t i ; \Gamma(x i ) = \Gamma i ; \Gamma = (c 1 ; : : : ; c d ): With these notations, it follows, as in the scalar case \Gamma ` 1 1 \Gamma xt ' = I F (t). The vector orthogonal polynomials (or of dimension d) are then defined by the following relations (R), for r = nd + k; 0 k ! d, s integer (R) 8 ! : \Gamma(x i P s r (x)) = 0 i = s; : : : ; s + n \Gamma 1 c ff (x s+n P s ..