ANALYTICAL ANALYSIS OF INTERFACIAL STRESSES IN FRP-RC HYBRID BEAMS WITH TIME-DEPENDENT DEFORMATIONS OF RC BEAM

In this paper, the effect of time-dependent deformations (such as shrinkage and creep) on the interfacial stresses between an RC beam and FRP plate is presented. For this end, a closed-form solution for such stresses in externally FRP plated RC beams including creep and shrinkage effects is presented. The developed model is formulated to predict the interfacial stresses at time ‘t’, in which the RC beams have been already subjected to creep and shrinkage effects. The adherend shear deformations have been included in the present theoretical analysis by assuming a parabolic shear stress through the thickness of the RC beam and the FRP panel. Contrary to some existing studies, the assumption that both RC beam and FRP panel have the same curvature is not used in the present investigation. This research is helpful for the understanding on mechanical behavior of the interface and design of the FRP-RC hybrid structures.     

Investigations of hyperfine structure and isotope shift predictions in Hf II

The fine structure of the even‐parity low configurations of singly ionized hafnium has been reanalyzed by simultaneous parameterization of the one‐ and two‐body interactions for the model space (5d + 6s)³. Using the calculated eigenfunctions, the magnetic‐dipole A hyperfine constants for the whole 37 existing levels of the model space were predicted and compared partially with those obtained using relativistic configuration‐interaction approach. Moreover, combined with experimental data, previously given in the literature, and pseudo‐relativistic Hartree–Fock estimates, the field shifts (FSs) and specific mass shifts (SMSs) of numerous configurations are deduced: FS(5d¹6s²) = 2265 MHz, FS(5d³) = ?1958 MHz, FS(5d¹6p²) = ?1696 MHz, FS(6s²6p¹) = 3135 MHz, and SMS(5d¹6s²) = ?78 MHz, SMS(5d³) = 64 MHz, SMS(6s²6p¹) = ?228 MHz, referred to 5d²6s for the pair ¹⁷⁸Hf–¹⁸⁰Hf. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem, 2012