The reduced stiffness conditions of steel W-Shape sections were evaluated and used to develop a new inelastic material model for a given axial load and bending moment.The new material model allows for direct input of ...The reduced stiffness conditions of steel W-Shape sections were evaluated and used to develop a new inelastic material model for a given axial load and bending moment.The new material model allows for direct input of paramters to adjust the stiffness reduction based on the W-shape’s dimensional properties,axis of bending,axial load and residual stress ratio.Numerous second-order,inelastic analyses up to the limit load were performed on three steel building frames using the new material model and the inelastic material model used in the AISC direct analysis method.Discussion is given regarding the two material models and their ability to match the ultimate load capacity results of the three test frames.展开更多
An inelastic material model that was previously developed by the author for standard W-Shapes was adapted for use to model the behavior and strength of rotary-straightened hot rolled W-Shape sections.Using a published...An inelastic material model that was previously developed by the author for standard W-Shapes was adapted for use to model the behavior and strength of rotary-straightened hot rolled W-Shape sections.Using a published residual stress model for these W-Shapes,limit load analyses were conducted using the material model in MASTAN2 and were compared with published finite element results.The material model required an adjustment to the initial yield moment conditions and residual stress ratios.Comparisons with published results indicate that these minor modifications were sufficient to provide very good modeling agreement.The previously developed material model can be used effectively to model the limit load conditions of rotary-straightened hot rolled W-Shape beams and beam-columns in steel frames.The effect of rotary-straightening W-Shapes is more significant for minor axis bending conditions and this becomes more pronounced as the floor load magnitudes increase.展开更多
A new material model for beam elements was developed for use as normalized tangent modulus expressions when performing 3-dimensional second-order inelastic analyses of steel I-section beams.The stiffness matrix of a 1...A new material model for beam elements was developed for use as normalized tangent modulus expressions when performing 3-dimensional second-order inelastic analyses of steel I-section beams.The stiffness matrix of a 14 degree-of-freedom beam element was updated to include the effects of yielding on St.Venant’s torsion and bimoment stiffness at the initial and terminal nodes.A validation study compared the new model’s results with those from published detailed finite element analyses and was found to be in very close agreement.A biaxial end-moment study with two different depth-to-flange-width ratios provided expected and consistent results over a range of moment conditions.展开更多
文摘The reduced stiffness conditions of steel W-Shape sections were evaluated and used to develop a new inelastic material model for a given axial load and bending moment.The new material model allows for direct input of paramters to adjust the stiffness reduction based on the W-shape’s dimensional properties,axis of bending,axial load and residual stress ratio.Numerous second-order,inelastic analyses up to the limit load were performed on three steel building frames using the new material model and the inelastic material model used in the AISC direct analysis method.Discussion is given regarding the two material models and their ability to match the ultimate load capacity results of the three test frames.
文摘An inelastic material model that was previously developed by the author for standard W-Shapes was adapted for use to model the behavior and strength of rotary-straightened hot rolled W-Shape sections.Using a published residual stress model for these W-Shapes,limit load analyses were conducted using the material model in MASTAN2 and were compared with published finite element results.The material model required an adjustment to the initial yield moment conditions and residual stress ratios.Comparisons with published results indicate that these minor modifications were sufficient to provide very good modeling agreement.The previously developed material model can be used effectively to model the limit load conditions of rotary-straightened hot rolled W-Shape beams and beam-columns in steel frames.The effect of rotary-straightening W-Shapes is more significant for minor axis bending conditions and this becomes more pronounced as the floor load magnitudes increase.
文摘A new material model for beam elements was developed for use as normalized tangent modulus expressions when performing 3-dimensional second-order inelastic analyses of steel I-section beams.The stiffness matrix of a 14 degree-of-freedom beam element was updated to include the effects of yielding on St.Venant’s torsion and bimoment stiffness at the initial and terminal nodes.A validation study compared the new model’s results with those from published detailed finite element analyses and was found to be in very close agreement.A biaxial end-moment study with two different depth-to-flange-width ratios provided expected and consistent results over a range of moment conditions.
