An overview of the plastic-hinge analysis of 3D steel frames

Asia Pacific Journal on Computational Engineering

Table 9 Features of the CEPAO program

Features	Problem types
Features	Elastic–plastic analysis	Limit analysis	Shakedown analysis	Limit optimization	Shakedown optimization
Orbison yield surface (“Plastic-hinge modeling”)^a	×
AISC yield surface (“Plastic-hinge modeling”)		×	×	×	×
P-δ effect (“Member modeling”)	×
Spread of plasticity in the plastic hinge (“Member modeling”)	×
Initial imperfections (“Member modeling”)	×
Lateral-torsional buckling (“Member modeling”)	×^(c)
Local buckling (“Member modeling”)	×
Member stability check^b				×	×
Conventional second-order approach (“Large displacements”)	×
Co-rotational approach (“Large displacements”)	×
Semi-rigid connection (“Consideration of connections”)	×
Partial connection (“Consideration of connections”)	×	×	×	×	×
Cost of connection (“Consideration of connections”)				×	×

“x”: implanted in the program
^aThe first coefficient (1.15 in Eq. (1)) has been replaced by 1.0 in CEPAO
^bAs the different effects (second-order, P-δ, etc.) have been not yet introduced in the optimization options, so a stability check according to Eurocode 3 has been adopted to check for individual members
^cThe practical method proposed in Kim [45] have been adopted in the program
In the CEPAO, Newton–Raphson method (See Chan [7]) is used for the incremental-iterative strategy and the force incremental method (See Wang [74]) is adopted to recover the element forces