Trend Toward Advanced Analysis Introduction Design Formats Allowable Stress Design (ASD) Plastic Design (PD) Load and Resistance Factor Design (LRFD) Advanced Analysis/Design AISC-LRFD Design Method Overview of AISC-LRFD Design Equations Column Curves Beam-Column Interaction Equations Effective Length Factor Moment Amplification Factor Illustrative Example 1: Two-Bay Unbraced Frame Illustrative Example 2: Leaning Column Frame Semi-Rigid Frames Methods of Advanced Analyses Plastic-Zone Method Quasi-Plastic Hinge Method Elastic-Plastic Hinge Method Notional-Load Plastic-Hinge Method Refined-Plastic Hinge Method Why Advanced Analysis Summary Practical Advanced Analysis Introduction Key Factors Influencing Steel Frame Behavior Gradual Yielding Associated with Flexure Gradual Yielding Associated with Residual Stresses Second-Order Effects Geometric Imperfections Connection Nonlinearity Desirable Attributes for Practical Advanced Analysis Second-Order Refined Plastic Hinge Analysis Stability Functions Accounting for Second-Order Effect Incremental Force-Displacement Relationship Cross-Section Plastic Strength Modification of Element Stiffness for the Presence of Plastic Hinges Tangent Modulus Model Associated with Residual Stresses Two-Surface Stiffness Degradation Model Associated with Flexure Analysis of Semi-Rigid Frames Types of Semi-Rigid Connections Practical Modeling of Connections Formulation of Initial Stiffness and Ultimate Moment Capacity Empirical Equation for Shape Parameter Practical Estimation of Three-Parameters Using Computer Program Incremental Force-Displacement Relationship Accounting for Semi-Rigid Connections Geometric Imperfection Methods Explicit Imperfection Modeling Method Equivalent Notional Load Method Further Reduced Tangent Modulus Method Numerical Impleme