|
Bond-slip Model to Capture Strain Penetration Effects |
|
|Home|Problem statement|Model development|Simulation examples|References|Contact us|FAQ| |
| Validation of bar stress vs. slip model: |
|
The applicability of the material model to describe the bar stress vs. loaded-end slip response under monotonic loading is demonstrated below by comparing experimental data from two bar pull-out tests with the corresponding theoretical curves. The parameters used to define the theoretical curves are included in the figure. A good agreement is seen between the theoretical curves and experimental data, indicating that the model is capable of capturing the strain penetration effects in the analytical simulation of concrete flexural members. Nevertheless, the determination of the model parameters needs further investigation. |
|
|
| Example: bridge Tee-joint system: |
|
|
A bridge tee-joint system (specimen IC1) tested in an inverted position by Sritharan et al. was studied to verify the feasibility of the proposed model for analyzing a structural system. This specimen with a conventional reinforced concrete cap beam evaluated a new design method suitable for bridge cap beam-to-column joints. Under constant axial load of 90 kips, the column was subjected to cyclic lateral loading at a height of 72 in. above the column-to-cap beam interface. The yield lateral displacement for the tee-joint system was reported to be 0.67 in. with the corresponding lateral resistance of 56 kips. The test joint experienced strength deterioration at lateral displacement of 4 in. due to formation of large joint cracks and subsequent joint damage. |
 |
|
The simulation model included six fiber-based beam-column elements for the cap beam and four beam-column elements for the column. An additional fiber-based beam-column element with the elastic column section properties modeled the joint. The zero-length section element is located between this elastic element and the adjoining column element.
The
analysis, which included the strain penetration effects, produced
force-displacement response that closely matched with the measured
response in both loading directions. The
analysis that did not include the strain penetration effects
overestimated both the lateral load resistance and the
unloading-reloading stiffness. Furthermore, the analysis that
ignored the strain penetration effects overestimated the column end
curvature by approximately 90% towards the end of the test, indicating
that the bar slip due to strain penetration greatly affects the local
response measures that are indicative of damage to the plastic hinge
region. A significant improvement to the moment-curvature response
prediction was obtained when the analysis included the strain
penetration effects.
|
| Examples: short rectangular column |
|
|
The short rectangular column (specimen U6) was designed and tested by Saatcioglu and Ozcebe. The testing of this column was part of a study that evaluated the effects of confinement reinforcement specified in ACI 318-83 on the ductility capacity of short columns. The column had a square cross section and a clear height of 40 in. above the footing. The column was modeled using five fiber-based beam-column elements.
|
| Examples: circular column |
|
|
The circular column tested by Smith served as the reference column for an investigation on strategic relocation of plastic hinges in bridge columns. This column had a clear height of 144 in. above the column footing. Under constant axial load of 400 kips, the column was loaded cyclically. The failure of the column occurred due to fracture of the longitudinal bars at the column base, after attaining lateral displacement of 13 in. with a lateral resistance of 80 kips. The column model contained five fiber-based beam-column elements.
|
| Examples: concrete walls |
|
|
Coming
soon...
|
|Home|Problem statement|Model development|Simulation examples|References|Contact us|FAQ|