Nagrinėjamas kriogeninio įrenginio seisminės analizės uždavinys baigtinių elementų metodu. Kriogeninį įrenginį sudaro erdvinis rėmas su lakštinio plieno apvalkalu. Pateikiami du seisminio modeliavimo uždaviniai. Pirmajame uždavinyje pateikiamas toks seisminės analizės maternatinis modelis, kuris įvertina seisminį procesą laike. Tokio proceso pavyzd...
In the article, an isolated acoustic resonator consisting of a cylinder-shaped hole of variable volume and with large and variable diameter is theoretically analyzed. Theoretical formulaes by which sound absorption of such resonator is computed are presented. The computations incorporate the influence exerted by overtones, i.e. odd harmonics, and s...
Heat and fluid flow exist not only in ingots or big size welds but also in small size microplasma arc melted weld pool. Edge weld pool geometry depend from interfacial energy, direction of the fluid flows in the weld pool caused by thermocapilary convection. Thermocapilary convection is the dominant flow mechanism under downhand welding conditions....
The author presents results of his own experiments for determining strength parameters of steel in thermal conditions of fire on which calculations of fire resistance can be based. The author suggests the calculation of the thermal strength parameters on the basis of noncoventional tensile test in thermal conditions described by the “time-temperatu...
A problem of elastic structures stress-strain field determination is considered in this article. A theoretical background and computation algorithms of equilibrium finite element method are presented there. The different external effects are estimated, namely: load, prestressing, inicial strains and support settlements. The dual relationships (equi...
This paper presents the problem of balancing specific construction processes with cyclic configuration. The processes of assembly of forming equipment in a monolithic housing building are an example of the consideration. The rules decomposition and synthesis at the production system has been used. Three examples of the loss functions are given. The...
The general dual mathematical models (static and kinematic formulations) of the limit load and rigidplastic body parameters optimization problems are formed on the basis of extremal energy principles and theory of duality. Yield conditions are controlled not only in volume of finite elements, but also at the surfaces between elements. Therefore the...
Ground compaction zone develops under action of structure foundation. Boundaries of it could be limited by a distance at which pressure from structure action is equal to structural strength of the soil. The structural strength of soil can be expressed by the parameters of shear resistance—the cohesion and the angle of the internal friction. These p...
Straipsnyje pateiktas universalus sluoksniuotos plokštės netiesinės medžiagos baigtinių elementų modelis, pritaikytas supleišėjusios gelžbetoninės plokštės skaičiavimui. Pasirinktas sudėtingas analitiškai suformuotas trečios eilės trikampis sluoksniuotas Reisnerio-Mindlino plokštės elementas, turintis 50 laisvės laipsnių. Programa įvertina atskirų ...
Methodical aspects of the reliability-based structural optimisation using stochastic quasigradient methods are considered. For an example of the simply supported reinforced concrete beam, the employment of the Lagrange multiplier method that belongs to the class of stochastic quasigradient methods is demonstrated. The classical optimum design goal ...
