Evaluation of Shear Effect on Deflection of RC Beams

This study evaluates the effect of shear on the deflection of reinforced concrete (RC) beams subjected to combined bending and shear. A total of nine simply supported beams were manufactured with the shear span-to-depth ratio, tension steel ratio, and shear capacity ratio as test variables. The experimental results were used to evaluate the effect of shear on the deflection by separating them into flexural and shear deformations. The theoretical deflection of the specimens was calculated using the effective moment of inertia equation recommended by ACI 318-19 based on the curvature relationships and experimental results of the flexure critical beams. By comparing the experimental and analytical results, it was revealed that the deflection obtained using the ACI equation underestimated the experimental results by up to about 1.6 times when the shear effect was large.

Parameter Optimization and Experimental Analysis of Passive Energy Storage Power-Assisted Exoskeleton

To address the occurrence of lumbar spine disease among labor workers who carry heavy objects, a passive energy storage based exoskeletal apparatus was designed to assist, using springs as energy storage elements and utilizing the change in energy that occurs when the human body is bent during the process of lifting objects. First, the mechanism of the exoskeleton was statically modeled; the spring stiffnesses and the locations of support points were used as design variables to optimize the model by optimizing the effective moment on the lumbar spine. Next, an optimized algorithm (Optdes-Sqp) based on the Newton method for solving quadratic programming subproblems was applied to optimize the stiffnesses of compression and extension springs and the positions of the upper support points of each spring. The accuracy of the simulated model was also verified using MATLAB software. Finally, the effect of optimization was verified, and the respiratory rates and heart rates of subjects before and after wearing the exoskeleton were analyzed. The experimental results show that the exoskeleton designed in this study assisted the subjects, and the results lay the foundation for follow-up designs and studies of exoskeletons.

Study of angular momentum effect on the fission process by angular anisotropy method in heavy-ion-induced reactions

The study of compound nucleus characteristics through fission fragment properties is a powerful tool to understand the fission mechanism of excited nuclei formed in heavy-ion-induced reactions. In this work, angular anisotropies of fission fragments from fissioning nuclei [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text] with normal behaviors in angular anisotropy have been analyzed. In this way, the quadrupole deformation parameter of the compound nucleus is calculated by comparison between the experimental data of angular anisotropy and those predicted by the standard saddle-point statistical model. Then the rotational energy, the fission barrier height, and the effective moment of inertia of the compound nucleus are obtained through the calculated quadrupole deformation parameters. It is observed that the quadrupole deformation parameter decreases with increasing the mean square angular momentum. The obtained results illustrate that the rotational energy and the effective moment of inertia increase almost linearly with increasing the mean square angular momentum, while the fission barrier height decreases as expected. However, the calculated values of fission barrier height overestimate the rotating finite-range model predictions. Also, the calculated values of effective moment of inertia represent a nearly linear trend despite those predicted by the rotating finite-range model. In order to discuss the physical ideas underlying the effect of angular momentum on the fission properties, the interaction potential energy during the capture process is studied for the lightest and heaviest reaction systems.

ENTRAINMENT FACTOR OF INDIVIDUAL GLITCH FRACTIONAL MOMENT OF INERTIA

The superfluid in the inner crust of a neutron star is assumed to be the reservoir of momentum released in a pulsar glitch. Recently, due to crustal entrainment, it appears debatable whether the magnitude of the inner crust is sufficient to contain the superfluid responsible for large glitches. This paper calculates the fractional moment of inertia (FMI)(i.e. the ratio of the inner crust superfluid moment of inertia to that of the coupled components) associated with individual glitches. It is shown that the effective moment of inertia associated with the transferred momentum is that of the entrained neutrons. The FMI for glitches in three pulsars, which exhibit the signature of exhausting their momentum reservoir, were calculated and scaled with the entrainment factor. Some of the glitches require an inner crust superfluid with moment of inertia larger than the current suggested values of 7-10% of the stellar moment of inertia.