Inelastic Asymmetry Research Articles

A Phenomenological Study on Inelastic Torsion Caused By Nonlinear Behavior Changes during Earthquake Excitations

Torsion of many symmetric structures, which were designed based on the seismic codes, is due to their asymmetricity induced during inelastic behavior. Although the structure was designed symmetrically assuming elastic based criteria, different factors such as material inconsistency in structure, construction details discrepancy and construction errors may result in asymmetric behavior in inelastic deformation range. So far, these considerations have been rarely contemplated in previous published investigations and should be studied regarding the importance of irregularity in increase of seismic demand of structures in the inelastic range. In this paper, as the first step, the asymmetry and irregularity in plan due to non-similar inelastic characteristics with respect to axis passing through center of gravity as well as the effect and importance of each irregularity factors are studied by changing the excitation properties applying to one-storey one-bay steel structures. This simplified structure is chosen due to studying and illustrating the absolute effect of this kind of irregularity in which higher mode effect is eliminated. The results show that the behavior of a structure with inelastic asymmetry is completely different from the structure with elastic asymmetry. As for inelastic asymmetry structure, although the translational and rotational oscillations before yielding were uncouple, these DOFs after yielding become coupled until reaching the terminal rotation point (rotation reaches a constant value) and then become uncoupled, i.e., again oscillated symmetrically. This behavior is different from the structures with elastic asymmetricity, in which the translational and rotational movements being coupled during all the excitation time. This effect has not been recognized in previews studies on inelastic behavior of initially elastic symmetry buildings. The study of these behaviors aids the designer to choose the appropriate rehabilitation method for a vulnerable irregular structure.

The angular distribution of asymmetry in scattering of spin-polarised electrons by spin-polarised hydrogen atoms. II

Several theoretical models are used to study the angular distribution of the elastic and inelastic asymmetry in the scattering of spin-polarised electrons by spin-polarised hydrogen atoms in the energy range from 20 to 200 eV. The preliminary results of Edmunds, McDowell and van de Ree (1983a) are confirmed in the cases of the 1s to ns (n=1,2) transitions, and new results are presented for the 1s to 2pmu ( mu =0,+or-1) and for the full n=1 to n=2 transitions.

Differential cross sections, polarisations and proton-gamma angular correlations for 54Fe, 60Ni(p, p) and (p, p′γ) at 10 MeV

Data are presented for the differential cross sections and polarisations for 54Fe(p,p) and 60Ni(p, p) and for the cross sections, proton asymmetries and the spin-flip angular correlation for 54Fe(p, p'γ) and 60Ni(p, p'γ) (first excited states). The incident energy is 10 MeV in each case. The cross section and angular correlation results are compared with the predictions of a simple model involving direct and compound nucleus contributions, permitting an estimate of the magnitude of the direct component to be made. The inelastic asymmetry data are not well described by this model.

Inelastic Scattering of 40-MeV Polarized Protons

The left-right asymmetry and differential cross section for the inelastic scattering of 40-MeV polarized protons were measured over a large angular region for each of the following ${2}^{+}$ excitations: 1.78 MeV in $^{28}\mathrm{Si}$, 1.41 and 2.97 MeV in $^{54}\mathrm{Fe}$, 1.45 MeV in $^{58}\mathrm{Ni}$, and 1.33 MeV in $^{60}\mathrm{Ni}$. Some asymmetry and cross-section data were also obtained for ${3}^{\ensuremath{-}}$ states: 6.9 MeV in $^{28}\mathrm{Si}$, 4.8 and 6.4 MeV in $^{54}\mathrm{Fe}$, 4.5 MeV in $^{58}\mathrm{Ni}$, and 4.08 MeV in $^{60}\mathrm{Ni}$. The inelastic scattering was analyzed in the distorted-wave approximation, using the collective-model extension of the optical-model potential determined by fitting elastic polarization and cross-section measurements for each target. The inelastic asymmetry and cross-section data are best reproduced with a collective-model interaction obtained by deforming the complete optical potential, including its imaginary and spin-orbit parts.

Inelastic proton scattering asymmetries at 8.9 MeV

The asymmetry in the inelastic scattering of a polarized proton beam from a magnesium target has been measured at a number of angles and at three different energies. A comparison between the inelastic asymmetries and the corresponding elastic asymmetries shows that in all cases they have opposite sign.

The asymmetry of 155 MeV protons elastically and inelastically scattered from carbon, oxygen, and calcium

Abstract The asymmetry of protons scattered elastically and inelastically from oxygen and calcium has been studied with the conventional double scattering technique using range telescopes. Results are given for the asymmetry in scattering from oxygen and calcium together with improved values of previously reported carbon data. The angular distributions of the elastic asymmetry are quite similar for the three elements. For the inelastic asymmetry of oxygen and calcium it has been possible to obtain only qualitative results.