000012515 001__ 12515
000012515 005__ 20160816141450.0
000012515 04107 $$aeng
000012515 046__ $$k2016-05-09
000012515 100__ $$aZachwieja, J.
000012515 24500 $$aSERVICE LIFE OF ROTORS UNDER MECHANICAL AND THERMAL STRESS

000012515 24630 $$n22.$$pEngineering Mechanics 2016
000012515 260__ $$bInstitute of Thermomechanics AS CR, v.v.i., Praha
000012515 506__ $$arestricted
000012515 520__ $$2eng$$aDynamic balancing of a rigid rotor should, at least in its final stage, be carried out at its operational speed, where its rotational frequency is often close to its resonance frequency. It is an adverse phenomenon, since even a minor constraint may induce high amplitude vibrations, limited by the attenuation. The service life of a rotor, mainly its bearings is thus significantly reduced. Balancing the rotor using the influence coefficient method at a frequency close to its resonance frequency is difficult due to the rapid changes in phase angle of a vector of the rotor response to constraints from the attached test weights. An optimal solution is to operate outside the rotor’s resonance zone. A quick and efficient method is to change its rotational speed, however, it may have some side effects. The rotors used in jet engines and power turbines, as well as rotors used in clinker cooler fans in cement plants and heating system fans in various types of furnaces used in the glass-making industry operate in high-temperature conditions. High temperature gradients during furnace start-up may result in thermal stresses at the rotor disc cross-sections. Strength of steel is also rapidly reduced at high temperatures. Cumulative effects of mechanical and thermal stresses at reduced rotor material strength may result in failure after a short period of operation. The study discusses those issues in relation to the rotors under mechanical and thermal stresses.

000012515 540__ $$aText je chráněný podle autorského zákona č. 121/2000 Sb.
000012515 653__ $$astress analysis, balancing, natural frequency, external anisotropy, resonance zone

000012515 7112_ $$aEngineering Mechanics 2016$$cSvratka, CZ$$d2016-05-09 / 2016-05-12$$gEM2016
000012515 720__ $$aZachwieja, J.$$iPeszynski, K.
000012515 8560_ $$ffischerc@itam.cas.cz
000012515 8564_ $$s1012059$$uhttps://invenio.itam.cas.cz/record/12515/files/145cd_o_dyn.pdf$$yOriginal version of the author's contribution as presented on CD, id 145, section DYN.
000012515 962__ $$r12369
000012515 980__ $$aPAPER