A Nakhaei - Department of Mechanical Engineering, Babol Noshirvani University of Technology, Babol, Iran.
M Dardel - Department of Mechanical Engineering, Babol Noshirvani University of Technology, Babol, Iran.
M Ghasemi - Department of Mechanical Engineering, Babol Noshirvani University of Technology, Babol, Iran.
M Pashaei - Department of Mechanical Engineering, Babol Noshirvani University of Technology, Babol, Iran.

A simple method is proposed to model the open cracked beam structures. In this method, crack ismodeled as a beam element. Hence cracked beam can be assumed to be a beam with stepped crosssections, and problem of determining natural frequency and mode shape of cracked beam, can besolved as determining these characteristics for a beam with different lengths and cross sections. Withthis work, it is not necessary to model crack as lumped flexibility model in according to fracturemechanics and related sciences to obtain crack stiffness, and this spring model of crack can be usedfor further analysis.

CrackLumped Stiffness ModelStep BeamNatural FrequencyMode Shape