Fm. Alkhairi et Ae. Naaman, ANALYSIS OF BEAMS PRESTRESSED WITH UNBONDED INTERNAL OR EXTERNAL TENDONS, Journal of structural engineering, 119(9), 1993, pp. 2680-2700
Citations number
27
Categorie Soggetti
Engineering, Civil","Construcion & Building Technology
The present study describes a nonlinear analysis model developed for t
he prediction of the complete moment versus deformation response of co
ncrete beams containing bonded prestressing tendons, unbonded prestres
sing tendons (metallic or otherwise), and nonprestressed conventional
reinforcing bars. The model uses an extensive iterative procedure for
calculating the stress in unbonded tendons, f(ps), by performing a non
linear analysis at various locations along the beam. The analysis is p
erformed several times during any loading stage until the stress f(ps)
is calculated within a reasonable tolerance. Two important issues not
addressed in previous investigations are considered in modeling the c
urvature distribution, namely: (1) The effects of member span-to-depth
ratio and the level of shear force on the flexural deformations; and
(2) the change in eccentricity under load (i.e., second-order effects)
for beams containing external tendons. Experimental verification was
carried out using beam tests taken from 15 different investigations th
at occurred between 1962 and 1990. Excellent correlation was observed
between predicted results and experimental observations.