Steel Lab., Sejong University, Seoul, Korea Development of Software for Practical Nonlinear Inelastic Analysis S.E. Kim Department of Civil and Environmental Engineering Sejong University Seoul, Korea Steel Lab., Sejong University, Seoul, Korea

Contents Introduction Nonlinear Analysis Nonlinear Inelastic Analysis Verification Modeling and Design Principles Design Example Conclusions 세종대학교 Steel Lab

Incompatibility of Conventional Design Procedure Introduction Incompatibility of Conventional Design Procedure Linear Elastic Analysis of System Member Capacity Check by Design Equation Developed on Nonlinear Inelastic Concept Steel Lab., Sejong University, Seoul, Korea

Steel Lab., Sejong University, Seoul, Korea Introduction Analysis Methods Steel Lab., Sejong University, Seoul, Korea

Steel Lab., Sejong University Introduction Design Methods Steel Lab., Sejong University

Benefit of Nonlinear Inelastic Analysis Introduction Benefit of Nonlinear Inelastic Analysis Accounts for geometric and material nonlinearities. Not necessary for separate member capacity check. Overcomes the difficulties due to incompatibility. Steel Lab., Sejong University

Steel Lab., Sejong University Introduction Load-Displacement Steel Lab., Sejong University

Nonlinear Inelastic Analyses Introduction Nonlinear Inelastic Analyses FEM(ABAQUS, ANSIS, etc.) Accurate but not practical Plastic – Zone Second – Order Modified Plastic Hinge Acceptably accurate and practical Steel Lab., Sejong University, Seoul, Korea

Steel Lab., Sejong University Nonlinear Analysis 2-D Beam-Column Steel Lab., Sejong University

2-D Force - Displacement Nonlinear Analysis 2-D Force - Displacement Stability Functions Steel Lab., Sejong University

Steel Lab., Sejong University, Seoul, Korea Nonlinear Analysis Stability Functions positive in tension Steel Lab., Sejong University, Seoul, Korea

3-D Force - Displacement Nonlinear Analysis 3-D Force - Displacement Stability Function Steel Lab., Sejong University, Seoul, Korea

Inelastic Nonlinear Force - Displacement Nonlinear Inelastic Analysis Inelastic Nonlinear Force - Displacement Steel Lab., Sejong University, Seoul, Korea

Inelasticity Associated with Residual Stresses Nonlinear Inelastic Analysis Inelasticity Associated with Residual Stresses for Steel Lab., Sejong University, Seoul, Korea

Inelasticity Associated with Flexure Nonlinear Inelastic Analysis Inelasticity Associated with Flexure for Steel Lab., Sejong University, Seoul, Korea

Force-State Parameter() AISC-LRFD (Kanchanalai 1977) Nonlinear Inelastic Analysis Force-State Parameter() AISC-LRFD (Kanchanalai 1977) for Steel Lab., Sejong University, Seoul, Korea

Force-State Parameter() Orbison (1982) Nonlinear Inelastic Analysis Force-State Parameter() Orbison (1982) Where, (strong-axis) (weak-axis) Steel Lab., Sejong University, Seoul, Korea

Steel Lab., Sejong University, Seoul, Korea Nonlinear Inelastic Analysis Modification of Element Stiffness for the Presence of Plastic Hinge at End A Steel Lab., Sejong University, Seoul, Korea

Steel Lab., Sejong University, Seoul, Korea Verification Column Steel Lab., Sejong University, Seoul, Korea

Orbison’s Six-Story Space Frame Verification Orbison’s Six-Story Space Frame Material property Yield Stress 36 ksi Young’s modulus 30,000 ksi Shear modulus 11,500 ksi Load Uniform floor pressure 100 psf Wind load 6 kips (in the Y-direction) Steel Lab., Sejong University, Seoul, Korea

Steel Lab., Sejong University, Seoul, Korea Verification Load-Displacement Steel Lab., Sejong University, Seoul, Korea

Steel Lab., Sejong University, Seoul, Korea Modeling and Design Principles Proposed Modeling 요소수 : 10 개 Steel Lab., Sejong University, Seoul, Korea

Steel Lab., Sejong University, Seoul, Korea Modeling and Design Principles ABAQUS Modeling 요소수 : 50,000 개 Steel Lab., Sejong University, Seoul, Korea

Geometric Imperfection Modeling and Design Principles Geometric Imperfection Braced Member Unbraced Frame Steel Lab., Sejong University, Seoul, Korea

Steel Lab., Sejong University, Seoul, Korea Modeling and Design Principles Design Format AISC-LRFD : member Proposed : system Steel Lab., Sejong University, Seoul, Korea

Twenty-Two Story Frame Design Example Twenty-Two Story Frame Material property Yield Stress 36 ksi Young’s modulus 30,000 ksi Shear modulus 11,500 ksi Load Uniform floor load 115 psf Wind load 7. 8 kips (in the Y-direction) Steel Lab., Sejong University, Seoul, Korea

Plan and Elevation of 22-Story Frame Design Example Plan and Elevation of 22-Story Frame Plan Elevation Steel Lab., Sejong University, Seoul, Korea

Member Sizes of 22-Story Frame Design Example Member Sizes of 22-Story Frame Beams Columns (1-11 story) Columns (12-22 story) Steel Lab., Sejong University, Seoul, Korea

Steel Lab., Sejong University, Seoul, Korea Design Example Load-Displacement Steel Lab., Sejong University, Seoul, Korea

Steel Lab., Sejong University, Seoul, Korea Conclusions A practical inelastic nonlinear analysis of three-dimensional steel frames has been developed Stability functions enable only one or two element per member to capture nonlinear effects The CRC tangent modulus and softening plastic hinge model predict inelastic behavior reasonably well The proposed analysis can be used in lieu of the costly FEM analysis The proposed design method overcomes the difficulties due to incompatible of ASD and LRFD Steel Lab., Sejong University, Seoul, Korea