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|a Sistema de Bibliotecas de la Universidad Tecnológica de Panamá
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|a Seismic energy based damage analysis of the bridge columns /
|c Gilberto Axel Chang ; adviser Jhon B. Mander.
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|b State University of New York,
|c 1993
|a New York :
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|a aproximadamente 207 hojas :
|b ilustraciones, gráficas ;
|c 28 cm
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|a Tesis (
|b Doctor of Philosophy ). --
|c State University of New York. Faculty of the Graduate School. School of Civil and Envieronmental Engineering.
|d 1993.
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|a 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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|a 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 comparing the ratio of energy demand to capacity, inferences of column damageability or fatigue resistance are made. The complete analysis methodology for bridge columns is developed starting from basic principles. The hysteretic behavior of steel reinforcement is dealt with in detailed: stability, degradation and consistency of cyclic behavior is explained. An energy based universally applicable low cycle fatigue model for steel is proposed. A hysteretic model for confined and unconfined concrete subjected to both tension or compression cyclic loading is developed, which is also capable of simulating gradual crack closure. A Cyclic Inelastic Strut-Tie (CIST) model is developed, in which the comprehensive concrete model proved to be suitable. The CIST model is capable of assessing inelastic shear deformations with high accuracy, within the context of a Fiber Element (FE) program. A parabolic fiber element with parabolic stress function element for uniaxial flexure developed, as well as a rectangular fiber element with a quadratic interpolation function suitable for biaxial flexure. A smooth rule-based macro model for the simulation of the hysteretic behavior of reinforced concrete elements is developed. The model is capable of accurately simulating cyclic behavior when compared with actual experimental data, through use of an automated system identification procedure which proved to be very effective in finding the model parameters to best approximate member behavior. The macro model was calibrated to simulate the behavior of a full size bridge pier and then implemented into a SDOF non-linear dynamic analysis program to generate inelastic response spectra. In addition to the usual ductility-based inelastic spectra, several additional energy spectra are also generated which include: viscous damping, hysteretic energy, cyclic (fatigue) demand. These spectra are used as part of a rational methodology in which the cyclic demand on bridge columns is compared with the capacity predicted by Fiber-Element analysis.
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|a Gilberto Axel Chang.
|c D
|d Recibido:1997/01/06.
|h $100.00.
|e 900223561.
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900 |
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|a BUT-VE
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|c TESISD
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|a 37977
|b Madeline Rivera
|c 37977
|d Madeline Rivera
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|c 127051
|d 127051
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|0 0
|1 0
|2 ddc
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|7 3
|8 TES
|9 159375
|a BUT-VE
|b BUT-VE
|d 2022-05-18
|e D
|g 100.00
|l 0
|p 900223561
|r 2022-07-27
|t e.1
|w 2022-07-27
|y TESISD
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