Vol.1, No 10, 2003 pp. 1299 - 1310
UDC 621.873:331.453
FREQUENCY RESPONSE OF CRANE OPERATOR'S
SPINAL COLUMN TO RANDOM VIBRATIONS
Miomir Lj. Jovanović1, Janko D. Jovanović2
1Faculty of Mechanical Engineering, University of Niš
2Faculty of Mechanical Engineering, University of Montenegro
Abstract. Regarding impact of vibrations upon health, working activities and comfort of working machines operator, research of vibrations in different working regimes of bridge crane is done. Based on the results of vibration investigations the vibration influence upon human health, working activities and comfort in accordance with international standard ISO 2631-1 is analyzed. For working regimes, which were potentially critical according to this analysis, an analysis of dynamic behavior of operator's spinal column is done. As a result of the modal analysis natural frequencies and vibration mode shapes of spinal column within frequency range of working vibrations are determined; also, as a result of the conducted time-history analysis, the load of each vertebrae is determined. Human body is modeled by means of finite elements, so spinal column, visceral column, head, torso segments, pelvis and buttocks tissue are modeled in the midd-sagital plane by means of elements such as: beam, spring and mass element.
FREKVENTNI ODGOVOR KIČMENOG STUBA OPERATERA
DIZALICE NA SLUČAJNU OSCILATORNU POBUDU
S obzirom na značaj koji vibracije imaju na zdravlje, radnu sposobnost i udobnost operatera radnih mašina, sprovedeno je istraživanje vibracija u različitim radnim režimima mosne dizalice. Na bazi rezultata mjerenja vibracija sprovedena je analiza njihovog uticaja na ljudsko zdravlje, radnu sposobnost i udobnost prema međunarodnom standardu ISO 2631-1. Za radne režime, koji su se prema ovoj analizi pokazali kao potencijalno kritični, sprovedena je analiza dinamičkog ponašanja kičmenog stuba operatera. Modalnom analizom su određene vrijednosti sopstvenih frekvencija i oblici oscilovanja kičmenog stuba, u frekventnom opsegu radnih vibracija, a vremenskom analizom opterećenje pojedinih pršljenova. Ljudski organizam je modeliran konačnih ele-mentima, pri čemu su kičmeni stub, unutrašnji organi, glava, torzo, karlica i butine modelirani u uzdužnoj ravni konačnim elementima poput: grede, opruge i koncentrisane mase.