THE STUDY OF THE BEHAVIOR UNDER STATIC AND DINAMIC LOAD OF THE MAIN BEAM (PROFILE „I”) OF A PORTAL CRANE (GANTRY CRANE)
PART II – THE STATE OF DEFORMATION OF THE MAIN BEAM IN THE „ANIMATION” WORKING MANNER
The lifting of the load at a certain height, its stop with a waiting of a 5 s, the descent of the load with a delay of 5 s, the descent of the load with its halt and waiting of approximately 5 s, leads to a certain load of the structure of the portal crane. Therefore one establishes that in the structure of the main beam appear compelled oscillations. In the frequency spectrum of the induced oscillatory motion, the main weight is that of the oscillation whose frequency is equal to the force in the driving cable; one establishes that the Eigen frequencies of the whole structure – the portal crane as a whole, are excited, too. Hence, the approach performed by the authors in the following study: a favourable working of the crane means that the Eigen frequencies of the structure as a whole must be outside the frequency field of the excitation forces, main beam: the state of stress and deformation under static and dynamic load.
Keywords: portal crane, force, structure, animation, frequency
Cuvinte cheie: macara portal, forță, structură, animație, analiză în frecvență
