An economic continuous calculation scheme for the stefan multidimensional problem

To form a necessary geometry of a hollow billet to be rolled at a pipe rolling line, stable dynamics of the base equipment of the automatic mill working stand has a practical meaning. Among the forces, acting on its parts and elements, significant by value short-time dynamic loads are the least studied phenomena. These dynamic loads arise during transient interaction of the hollow billet, rollers, mandrel and other mill parts at the forced grip of the hollow billet. Basing of the calculation scheme and dynamic model of the mechanical system of the ТПА 350 automatic mill working stand was accomplished. A mathematical model of dynamics of the system “hollow billet (pipe) – working stand” within accepted calculation scheme and dynamic model of the mechanical system elaborated. Influence of technological load of the rolled hollow billet variation in time was accounted, as well as variation of the mechanical system mass, and rigidity of the ТПА 350 automatic mill working stand. Differential equations of oscillation movement for four-mass model of forked sub-systems of the automatic mill working stand were made up, results of their digital calculation quoted. Dynamic displacement of the stand elements in the inter-roller gap obtained, which enabled to estimate the results of amplitude and frequency characteristics of the branches of the mill rollers setting. It was defined by calculation, that the maximum amplitude of the forced oscillations of elements of the ТПА 350 automatic mill working stand within the inter-roller gap does not exceed 2 mm. It is much higher than the accepted value of adjusting parameters of the deformation center of the ТПА 350 automatic mill. A scheme of comprehensive modernization of the rollers setting in the ТПА 350 automatic mill working stand was proposed. It was shown, that increase of rigidity of rollers setting in the ТПА 350 automatic mill working stand enables to stabilize the amplitude of forced oscillations of the working stand elements within the inter-rollers gap and considerably decrease the induced nonuniform hollow billet wall thickness and increase quality of the rolled pipes at ТПА 350.

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INDICATIONS OF A ΔI=1/2 RULE IN THE STRONG COUPLING REGIME

International Journal of Modern Physics A ◽

10.1142/s0217751x8800059x ◽

1988 ◽

Vol 03 (06) ◽

pp. 1385-1412

Author(s):

IAN G. ANGUS

Keyword(s):

Lattice Qcd ◽

Strong Coupling ◽

Computer Algebra ◽

Free Parameter ◽

Hamiltonian Formalism ◽

Strong Coupling Expansion ◽

Calculation Scheme ◽

Strong Coupling Regime ◽

Weak Decays ◽

The One

We will attempt to understand the ΔI=1/2 pattern of the nonleptonic weak decays of the kaons. The calculation scheme employed is the Strong Coupling Expansion of lattice QCD. Kogut-Susskind fermions are used in the Hamiltonian formalism. We will describe in detail the methods used to expedite this calculation, all of which was done by computer algebra. The final result is very encouraging. Even though an exact interpretation is clouded by the presence of irrelevant operators, and questions of lattice artifacts, a signal of the ΔI=1/2 rule appears to be observable. With an appropriate choice of the one free parameter, enhancements greater than those observed experimentally can be obtained. We also point out a number of surprising results which we turn up in the course of the calculation.

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GENERAL METHOD FOR CALCULATING BUTT AND ANGLE WELDS FOR STRENGTH

Spravochnik Inzhenernyi zhurnal ◽

10.14489/hb.2021.02.pp.028-033 ◽

2021 ◽

pp. 28-33

Author(s):

Yu. N. Vavilov ◽

I. Yu. Skobeleva ◽

I. A. Shirshova

Keyword(s):

Calculation Method ◽

Calculation Scheme ◽

Calculation Procedure ◽

Fillet Welds ◽

Specific Design ◽

Strength Of Materials ◽

Butt Welds ◽

Strength Based ◽

Design Solutions ◽

General Method

The existing methods for calculating butt and fillet welds are private, developed for specific design solutions that do not take into account the variety of weld shapes and the variety of combinations of forces and moments. The article provides a general method for calculating butt and fillet welds for strength, based on the calculation method for nominal stresses, adopted in the strength of materials. This technique was used without any changes for the calculation of butt welds, since the weld is an extension of the part. The calculation of fillet welds is based on two assumptions, on the basis of which a calculation scheme has been developed, which makes it possible to use the calculation method for rated stresses. The article proposes two design schemes, considers the calculation procedure and derives two generalized strength conditions for the verification calculation of butt and fillet welds.

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