Horea FURDUI


29-77 INFLUENŢA DEFECTULUI ASUPRA MODIFICĂRII TEMPERATURII CRITICE LA FLAMB

DAMAGE INFLUENCE ON THE CRITICAL BUCKLING
TEMPERATURE
This paper presents the influence of a transverse damage in a doubleclamped
beam upon the critical buckling temperature. First, the buckling
temperatures and subsequent loads are analytically investigated on an intact
prismatic beam, together with the dynamic behavior in terms of the natural
frequencies. Afterwards, the effect of a transverse damage is considered, and a
relation expressing the frequency alteration due to the crack is provided. To
prove the relation’s validity a finite element analysis was performed for some
particular cases, and the results compared with those obtained analytically. The
investigation did show a good concordance between the results obtained in the
two ways, proving the correctness of the analytical approach.
Keywords: double-clamped beam, damage, thermal buckling
Cuvinte cheie: grindă dublu încastrată, defect, flambaj, temperatură
critică

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27-83 INFLUENŢA EFECTULUI TERMIC ASUPRA FRECVENŢELOR PROPRII ALE GRINZILOR ÎNCASTRATE LA AMBELE CAPETE

THE EFFECT OF THERMAL LOAND ON THE NATURAL FREQUENCIES OF DOUBLE-CLAMPED BEAMS
The natural frequencies of double-clamped beams are influenced by environmental conditions and operational loads. For instance the temperature induces axial loads due to restraint displacements, which lead after a critical temperature increase to buckling. This paper clarifies the effect of external loads on the natural frequencies of beams.
Keywords: thermal loads, buckling, Euler-Bernoulli beam, natural frequency
Cuvinte cheie: încărcări termice, flambaj, grindă, frecvenţe proprii

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26-38 INFLUENŢA TEMPERATURII ASUPRA FRECVENŢELOR PROPRII ALE ELEMENTELOR DIN STRUCTURI CU ZĂBRELE

TEMPERATURE EFFECT UPON THE NATURAL FREQUENCIES OF THRUSS ELEMENTS
In this paper we analyze the effect of temperature upon the natural frequencies of truss elements. Temperature changes influence the Young’s modulus in the sense that it decreases with increasing temperature, consequently structural elements frequencies decrease. However, we demonstrate in this paper that the frequency changes due to temperature in natural environment are very small and do not dramatically influence the structures dynamic behavior.
Keywords: temperature, Young modulus, frequency, truss structures

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