A FINITE ELEMENT METHOD BASED ON ELASTIC MODULUS REDUCTION FOR THE LIMIT ANALYSIS OF RING-STIFFENED AXISYMMETRIC COMBINED SHELL

Based on elastic modulus reduction, a finite element method was proposed to plastic limit analysis for ring-stiffened axisymmetric combined shell. The ‘elastic state’, ‘local yield state’ and ‘section yield state’ of shell element were defined and the criterions for each state were established. The criterion for stiffener yielding was established too. The combined shell was loaded step by step, elastic-plastic state was simulated by reducing the elastic modulus of locally yielded shell element and the stiffener which yielded. The criterion for plastic limit state of ring-stiffened axisymmetric combined shell was presented, by which the plastic limit load of combined shell was determined. The computer program was developed. Numerical examples show that the proposed method is effective, the computed result is accurate, and can be applied in engineering.