Hassan MOGHADDAM - Professor, Department of Structure and Earthquake Engineering, Sharif University of Technology, Tehran, Iran
Rojin GHANDRIZ - PhD Candidate, Department of Structure and Earthquake Engineering, Sharif University of Technology, Tehran, Iran
Majid ERFANI - PhD student, Department of Structure and Earthquake Engineering, Sharif University of Technology, Tehran, Iran

In this paper the goal is to study where, when and how the cracks in the steel connection plate between beam and column initiate and how far would the crack continue before it fails and how to detect crack initiation and prevent the same by utilizing piezoelectric sensors. In this analysis piezoelectric is placed in line of crack propagation for sensing strain and changing it to voltage. A thin plate with edge notch which is an ideal model of typical beam to column connection is assumed. The uniaxial uniform load is applied on it.With the aid of ABAQUS software, the plate is analyzed in both elastic and plastic stages. The strain-stress curve with kinematic hardening part is considered and modeled with multi-linear method. The micromechanical based model Stress Modified Critical Strain (SMCS) model are utilized for prediction of ductile crack initiation. Based on the combined effects of the triaxiality and plastic strain, the model can capture the void growth phenomenon in steel material. The triaxiality and plastic strain for several load levels are obtained. The SMCS criterion corresponding to each load is calculated and the crack status is determined.

Fracture, Ductile Crack Initiation, Plastic Strain, Void Growth, SMCS, Piezoelectric Sensor