CONTENTS & ABSTRACTS
InEnglish. Summaries in Estonian
Proceedings of the Estonian Academy of Sciences.
Engineering
Volume 8 No. 3September 2002
Investigation of masonry arches; 147–161
Réka Macskási
Abstract. A method for computing masonry arches consisting of rigidbrick voussoires and deformable mortar layers is presented. The brick elementsare allowed to move and rotate relative to each other, according to thematerial model of the mortar. Non-linear constitutive law is applied toeccentric compression and the shear behaviour is determined by both the shearand normal stresses. The applied mathematical method produces the globalequilibrium path. The proposed algorithm is appropriate for analysing arches ofarbitrary geometry subjected to arbitrary static loads. Some examples whichshow the influence of the various shape and material parameters are given.
Key words: masonry arch, non-linear constitutive law, sliding,equilibrium path, third-order theory.
Residual stresses in different thermal spray coatings; 162–173
Harri Lille, Jakub Kõo, Priit Kulu, andToomas Pihl
Abstract. By testing a thin-walledringed coated specimen, we determined the through-thickness residual stressdistribution, the modulus of elasticity, and the coefficient of thermal expansionof different flame sprayed Cu-, Ni- and Ni-Al-based powder coatings, flamespray coatings, fused self-fluxing NiCrSiB alloy based coatings, and a highvelocity oxy-fuel (HVOF) sprayed tungsten carbide WC-17Co coating. Residualstresses were, as a rule, slightly larger on the outer surface than at thecoating–substrate interface, where they were close to adhesion strength. Thehighest residual compressive stresses were found in HVOF sprayed coatings whichhave high impact erosion wear resistance. The values of the moduli ofelasticity were lower or close to the corresponding values of the basicsubstance of the powder used for producing the coatings, while the coefficientsof thermal expansion were close to those of the basic substance.
Key words: thermal spraying,powder coating, ring specimen, strain gauge, residual stress.
Unstiffened thin-walled girder under uniformloading; 174–188
Priit Vilba and Siim Idnurm
Abstract. The paper focuses on the stresses and deformations of welded plategirders subjected to uniformly distributed edge loading. The critical loadparameters of the web plate under the action of edge loading, shear, bending,and compressive stresses are determined. The horizontal edges of the web plateare considered to be elastically restrained, with vertical edges simplysupported. The post-buckling behaviour of this web plate is analysed. In thepost-buckling situation, the parts of the web plate are assumed to be simplysupported and the edge load balanced by shear stresses on the adjacent edges.Numerical results of the continuous analytical and the finite element methodare compared with results obtained from the Eurocode 3 formulas and with thetest results.
Key words: plate girder, buckling load, post-buckling behaviour, ultimate load,Eurocode.
Flow modelling in the Pärnu Bay and the KihnuStrait; 189–203
Ülo Suursaar, Tiit Kullas, and Mikk Otsmann
Abstract. Flowfeatures are studied in the NE part of the Gulf of Riga using a 2D hydrodynamicmodel forced by the wind and sea level data of 1999 as well as by someconstructed stationary winds. Two flow patterns dominate in the Pärnu Bay. Themost frequent of them has an inflow along the Liu and Tahkuranna coasts and anoutflow along the trunk zone of the bay. Eastward motions predominate both inthe Kihnu Strait and Valgerand. High flow velocities, participating (along withstorm waves) in coastal erosion events, act 1-2 m above the average waterline andabout half of the year’s summary work of the flow by charging the coast is doneduring the 2-3 most stormy days of the year in the Pärnu Bay.
Key words: currents, storm surge, hydrodynamic model, water circulation, coastalengineering, Baltic Sea.
Instructions toauthors; 204–206
Copyright TransferAgreement; 207
