Search

In this study, a high-strength bolted prefabricated concrete beam-column junction is presented, and the prefabricated concrete beam-column joint parts are put through eight quasi-static tests. The axial compression ratio and the steel plate hoop thickness were used in extended parameter research using finite element software to completely examine the seismic performance of the construction. According to the findings, this node's ductility coefficient ranges from 2.57 to 3.69, which is bigger than 3. The specimen loses part of its bearing capacity and constantly loses ductility as the axial compression ratio rises. The failure displacement of the specimen decreases with an increasing axial compression ratio, but the yield displacement of the specimen is very slightly affected by the axial compression ratio. This node has an excellent energy dissipation capacity despite having a low viscous damping coefficient between 0.2 and 0.4, and when the axial pressure ratio rises, the capacity grows in response to the elevated pressure. Despite this, the energy consumption of the beam-column member is not significantly affected by the steel plate hoop thickness. Additionally, according to the variable-angle truss-arch model and taking into account the representation of the truss-arch model under different conditions, this paper presents the equation for the shear load capacity of diagonal sections of prestressed high-strength spiral hoop-restrained concrete beams under various conditions. [ABSTRACT FROM AUTHOR]

Geometry and mechanics have both a relevant role in determining the three-dimensional packing of 8 bubbles displayed in a similar foam structure. We assume that the spatial arrangement of bubbles obeys a geometrical principle maximizing the minimum mutual distance between the bubble centroids. The compacted structure is then obtained by radially packing the bubbles under constraint of volume conservation. We generate a polygonal tiling on the central sphere and peripheral bubbles with both flat and curved interfaces. We verify that the obtained polyhedra is optimal under suitable physical criteria. Finally, we enforce the mechanical balance imposing the constraint of conservation of volume.We find an anisotropy in the distribution of the field of forces: surface tensions of bubble-bubble interfaces with normal oriented in the circumferential direction of bubbles aggregate are larger than the ones with normal unit vector pointing radially out of the aggregate. We suggest that this mechanical cue is key for the symmetry break of this bubbles configuration.

Mass measurement of more than 500 kg on an electronic mass comparator has no better repeatability and linearity of measurement for meeting the calibration requirement of over class F1 weights from pharmacy and power generation plants. For this purpose, a new 2000 kg mechanical balance was developed by the National Institute of Metrology (NIM). The advantages of measurement of more than 500 kg on a new 2000 kg mechanical balance are introduced in the paper. In order to obtain high measurement uncertainty, four vertical forces of two sides of beam are measured and used as reference for adjustment of the beam position. Laser displacement sensors in the indication system are more effective for decreasing reading errors caused by human vision. To improve the repeatability and sensitivity of the equipment, a synchronous lifting control is designed for synchronously lifting the beam ends along the vertical direction. A counterweight selection system is developed to get any combination of weights in a limited space. The sensitivity of the new mechanical balance for 2000 kg is more than 1.7 parts in 10-4 rad/g. The extended uncertainties for the mechanical balance of 500 kg, 1000 kg and 2000 kg are 0.47 g, 1.8 g and 3.5 g respectively. [ABSTRACT FROM AUTHOR]