Seismic energy based damage analysis of the bridge columns /

Seismic energy based damage analysis of the bridge columns /

Abstract: This study is concerned with the computational modeling of energy absorption (fatigue) capacity of reinforced concrete bridge columns by using a cyclic dynamic Fiber Element computational model. The results are used with a smooth hysteretic rule to generate seismic energy demand. By compar...

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Detalles Bibliográficos
Formato: Tesis Libro
Lenguaje:Spanish
Publicado: New York : State University of New York, 1993
Tabla de Contenidos:
  • 1. Introduction. 1.1 Background.
  • 1.2 Integration of previous research work.
  • 1.3 Seismic evaluation methodologies.
  • 1.4 Scope of present investigation.
  • 2. Hysteretic and damage modeling of reinforced steel bars. 2.1 Introduction.
  • 2.2 Monotonic stress-strain curve. 2.2.1 The elastic branch.
  • 2.2.2 The yield plateau.
  • 2.2.3 Strain hardened branch.
  • 2.3 The menegotto-pinto equation. 2.3.1 Computation of parameters Q, f_Ch and R.
  • 2.3.2 Menegotto-pinto equation limiting case.
  • 2.4 Cyclic properties of reinforcing steel. 2.4.1 Envelope branches (rules 1 and 2).
  • 2.4.2 Reversal branches (rules 3 and 4).
  • 2.4.3 Returning branches (rules 5 and 6).
  • 2.4.4 First transition branches (rules 7 and 8).
  • 2.4.5 Second transition branches (rules 9 and 10).
  • 2.4.6 Strength degradation.
  • 2.5 Stress-strain model verification.
  • 2.6 Damage modeling.
  • 2.7 Damage model implementation and verification.
  • 2.8 Strain rate effects.
  • 2.9 Conclusions.
  • 3. Modeling stress-strain cyclic behavior of concrete. 3.1 introduction.
  • 3.2 Review of previous work in stress-strain relations for concrete. 3.2.1 Monotonic compression stress-strain equation.
  • 3.2.2 Initial modulus of elasticity.
  • 3.2.3 Strain at peak stress for unconfined concrete.
  • 3.2.4 Characteristic of the descending branch of the monotonic stress-strain curve for unconfined concrete.
  • 3.3 Recommended complete stress-strain curve for unconfined concrete.
  • 3.4 Confinement of concrete. 3.4.1 Confinement models.
  • 3.4.2 Confinement mechanism. 3.4.2.1 Confinement of circular sections.
  • 3.4.2.2 Confinement of rectangular sections.
  • 3.4.3 Confinement effect on strength.
  • 3.4.4 Confinement effect on ductility.
  • 3.4.5 Confinement effect on the descending branch.
  • 3.5 Concrete in tension.
  • 3.6 Dynamic effects on concrete behavior.
  • 3.7 Modeling hysteretic behavior. 3.7.1 Basic components of a hysteretic model.
  • 3.7.2 A general approach to assessing degradation within partial looping in a rule-based hysteretic model. 3.7.2.1 First partial reversal.
  • 3.7.2.2 Partial reloading.
  • 3.7.2.3 Partial unloading from a partial reloading.
  • 3.7.3 A smooth transition curve for mathematical modeling.
  • 3.8 Cyclic properties of confined and unconfined concrete. 3.8.1 Compression envelope curve (rules 1 and 5).
  • 3.8.2 Tension envelope curve (rules 2 and 6).
  • 3.8.3 Pre-cracking unloading and reloading curves.
  • 3.8.4 Post-cracking unloading and reloading curves.
  • 3.8.5 Pre-cracking transition curves.
  • 3.8.6 Post-cracking transition curve.
  • 3.9 Model verification.
  • 3.10 Damage analysis.
  • 3.11 Conclusions.
  • 4. Damage modeling of reinforced concrete columns using fiber-element analysis. 4.1 Introduction.
  • 4.2 Moment-curvature analysis for uniaxial bending.
  • 4.3 Moment-curvalure analysis for biaxial bending.
  • 4.4 Force-displacement analysis. 4.4.1 Elastic flexural deformation.
  • 4.4.2 Plastic flexural deformation.
  • 4.4.3 Elastic shear deformation.
  • 4.4.4 Inelastic shear deformation. 4.4.4.1 proposed cyclic inelastic strut-tie (cist) model for shear deformations.
  • 4.4.4.2 crack inclination angle.
  • 4.5 Validation of fiber-element model.
  • 4.6 Conclusions.
  • 5. Smooth asymmetric degrading hysteretic model with parameter identification. 5.1 Introduction.
  • 5.2 A smooth curve to fit two tangents. 5.2.1 The menegotto-pinto equation.
  • 5.2.2 Computation of parameters Q, f_Ch and R.
  • 5.3 Description of smooth hysteretic model. 5.3.1 Monotonic envelope curves.
  • 5.3.2 Reverse curves.
  • 5.3.3 Transition curves.
  • 5.3.4 Model summary.
  • 5.4 Parameter Identification. 5.4.1 Optimization method.
  • 5.4.2 Scaling.
  • 5.4.3 Constraining the parameters.
  • 5.4.4 Initial estimate.
  • 5.4.5 Order of parameter identification.
  • 5.5 Verification of smooth model and system identification method.
  • 5.6 Conclusions.
  • 6. Assessment of hysteretic energy demand. 6.1 Introduction.
  • 6.2 Elastic response of a SDOF system.
  • 6.3 Inelastic response of a SDOF system.
  • 6.4 Inelastic response spectra. 6.4.1 Displacement ductility spectra.
  • 6.4.2 Energy based spectra.
  • 6.5 Implementation and results.
  • 6.6 An ilustrative example.
  • 6.7 Conclusions.
  • 7. Summary, conclusions and recommendations. 7.1 Summary.
  • 7.2 Some specific conclusions.
  • 7.3 Recommendations for future research. - Appendix A. References.
  • Appendix B. RC-COLA source code.
  • Appendix C. OPTIMA source code.
  • Appendix D. GRAFIT III source code.

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