Earthquake-induced net section fracture in brace connections — experiments and simulations

Results from six tests, finite element simulations and a synthesis of previous test programs on slotted end bracing connections are presented. The main objective of the research is to examine the deformation capacity of these connections, with the ultimate objective of minimizing the requirement for net section reinforcement that is often inconvenient from the perspective of fabrication. The experiments and simulations feature commonly used pipe specimens and end details. The main parameters investigated include the gusset plate thickness, the slot length and introduction of a wrap-around weld that eliminates the reduced section at the edge of the gusset plate. The results indicate that even without reinforcement, the connections offer adequate to excellent deformation capacity if they are provided with the wrap-around weld or if the net section strength is larger than the gross yield strength. This may be achieved in situations where shear lag in the connection is minimal, and where the area reduction due to the slot is small relative to the gross area. Design considerations are presented along with limitations of the study.     

CROSS - a Program for Determination of Coefficients of Subgrade Reaction

Soil Mechanics and Foundation Engineering -     

Modification of Polycaproamide Composites Based on 1H,1H,13H-rihydroperfluorotridecan-1-ol and Montmorillonite

Fibre Chemistry - Modification of polycaproamide by 1H,1H,13H-trihydroperfluorotridecan-1-ol immobilized on montmorillonite produced an F-containing polymer composite. The structure of the...     

Improving the Quality of Cellulose for Use in Disposable Sanitary and Hygiene Products

Fibre Chemistry - Under modern conditions the creation of materials for sanitary hygiene and medical products based on cellulose is of paramount importance. Development and improvement in this area...     

Development of a Catalyst Based on Titanium Nanoparticles in a Zeolite Matrix

Glass and Ceramics - A catalyst was developed in the form of a composite based on a zeolite matrix modified with titanium nanoparticles based on zeolite raw materials from the Kulikovskoe deposit...     

Optimization of Technological Regulation of Container Glass Production: Best Available Technologies,General Binding Rules,and Carbon Intensity of Products

Glass and Ceramics - A system for technological regulation of adverse environmental impacts (AEI) that is based on the best available technologies (BAT) was analyzed. The expediency of updating the...     

Investigation of 12 – 15 Kev Electron Transmission Through Tapered Glass Capillaries

Glass and Ceramics - The results of experimental studies of the transmission of 12 and 15 keV electron beams through tapered glass macro-capillaries are presented. Measurements showed that there is...     

A Power-Supply Unit for Pulsed Lasers without a Storage Capacitor

A power-supply unit for pulsed lasers that are pumped by low- and medium-power flashlamps with long pump pulses that does not require a capacitive storage unit is described. The pump-pulse duration is limited by the radiation and thermal stability of the active elements and pump lamps. A functional diagram of the power-supply unit and a circuit diagram of its power system are presented. The basic parameters and elements of this unit, as well as the results of using a laser with the described power supply in experiments, are presented.     

Measuring the Beam Density of Accelerated <Superscript>12</Superscript>C Ions Using Computer Analysis of Microscopic Photographic Images of Etched CR-39 Plastic Surfaces

The numbers of detected ions and the beam density dispersions at different depths of plate locations that also cover the Bragg peak region were determined by automatically searching for etched micropores in photographs of surfaces of CR-39 plastic plates exposed to ¹²C ions with an energy of 216 MeV/amu in a chamber for radiobiological investigations at the TWAC–ITEP accelerator–accumulator facility. A computer method for seeking etched micropores along latent ion tracks in an exposed plastic is described. Frequency distributions of detected ions over microscopic areas of each surface for eight plates have been obtained and compared using a Gaussian function.     

Composition and Tribological Properties of Hardened Cutting Blades of Tillage Machines under Abrasive Deterioration

The article presents the results of metallographic study of low-carbon 20 steel grade and high-carbon 70 and 65G steel grades upon carburizing, heat treatment, and laser hardening. The change in the microhardness through the depth of the surface layer of steels and their abrasion resistance upon hardening under different conditions has been measured. Optimal hardening conditions have been proposed for steels for cutting blades of tillage machines that enable the durability of the blades to be improved.