V. N. Puchkov

Heat state of pendulum sliding bearings under seismic effects

Issues in the choice of self-lubricating antifrictional materials for pendulum sliding bearings used as seismic dampers are discussed. Such bearings are used in supports of essential constructions (including offshore drilling platforms) and other objects located in seismically dangerous regions to protect buildings from loads caused by earthquakes and other power effects. The heat state of seismic dampers is studied using various computer programs. The computation method suggested allows the selection of antifrictional materials for sliding bearings with account for their temperature resistance.

The effect of earthquake parameters on the tribological characteristics of friction pendulum bearings (seismic isolators)

Friction pendulum bearings have universal properties meeting various requirements during the use of buildings, bridges, and industrial structures. For a bearing, the period of vibrations, vertical load-carrying capability, damping, displacement capability, and response to a tensile load can be chosen independently. Dynamic vibration periods with durations of 1–5 s and displacements of up to 1.5 m are provided. Data on earthquake characteristics and the parameters of friction pendulum bearings are presented.

Tribological behavior of frictional seismic dampers of pendulum type

Frictional pendulum bearings have universal properties that can meet various requirements at service of buildings, bridges, and industrial constructions. The formulas for the average dimensionless wear rate and friction coefficient of the bearings are obtained. The use of the bearings as seismic dampers of shell drilling rigs is described and characteristics of the frictional pendulum bearings are given.

Investigation of friction units of nuclear plants operating in heavy high-temperature liquid-metal heat carriers. Part 2. Experimental results

The tribological problems posed by heavy liquid-metal heat carriers used in the circuits of nuclear power plants are discussed. The results of experimental study of the vibrational wear of heat-exchanging tubes in the interfaces with the spacing grates are presented. These results are applicable for testing the vibrational strength of the steam generator of a fast neutron reactor with lead heat carrier. Experimental investigation and service-life tests of involute-profile cylindrical tooth gears and sliding bearings working in fast neutron reactors containing the lead heat carrier are conducted. Experimental and theoretical study is performed on the wear of steel and cast-iron sliding bearings in the recycling pumps of reactors operating in lead, eutectic lead-bismuth and lead-lithium alloys. It is shown experimentally that the tooth gears from 40X13 steel and SCh20 grey iron are capable of operating in the lead heat carrier for 500 and 400 hours, respectively, at the temperature 450°C when the concentration of thermodynamically active oxygen in the lead is close to saturation, the contact stress in the gearing is 758 MPa, the gear rotational frequency is 500 min−1 or less, and the gear ratio is 1.5 (the peripheral velocity of the gear and the wheel over the pitchline is 2.1 m/s). The likely causes of destruction of the gear teeth are adhesive wear and insufficient heat resistance (refractorability) of the tooth material at 450–500°C.

Application of frictional pendulum sliding bearings for seismic insulation

The sea platforms Lun-A and PA-B of the Sakhalin-2 project erected off the northwestern coast of Sakhalin have been designed and constructed taking into account the severe regional seismicity in which they are used. Their design, which incorporates an effective frictional pendulum bearing (FPBs are capable of running damage- and failure-free when exposed to loads created by earthquakes, which occur once every 200 years, and should stay undamaged in the case of a rare earthquake, which occurs once every 2000 years [1–3]. When the Arkutun-Dagi deposit was put to use, the seismic reliability of oil producing Sakhalin-2 project was designed for use on the previously tested platforms at the Lun and Piltun-Astokh deposits. The Sakhalin-2 project was seismically protected and have been successfully and safely used since 2007. These works used experimental calculation techniques to estimate the life of the seismic insulating pendulum sliding bearing in order to determine its wear rate. The dependences of determining the wear rate are presented in summarized variables and the coefficient of friction and temperature assessments to establish the temperature condition of the FPB [4, 6].

Seismic isolators for petroleum and gas platforms of the “Sakhalin-2” project

Friction pendulum bearings have universal properties satisfying various demands when supporting buildings, bridges, and industrial facilities. The oscillation period of the bearing, vertical carrying capacity, damping, displacement ability, and ability to receive tensile load can be chosen independently. Dynamic oscillation periods from 1 to 5 s, shifts of up to 1.5 m, high carrying capacity and damping can be provided. Bearings can endure vertical loads of up to 13 500 tons and have minimal construction costs. Data are given on the influence of earthquakes and other force effects on the thermal state and characteristics of frictional pendulum bearings used as seismic isolators on petroleum and gas platforms of the “Sakhalin-2” project.

Application of frictional pendulum sliding bearings for earthquake engineering

The experimental calculation method for determining the operation time of frictional pendulum bearing is developed. The method for estimating the friction factor of frictional pendulum bearing is proposed. The perspectives of development of an antifrictional self-lubricating covering with the desired tribological properties are analyzed. Thermal state of frictional seismic isolators is studied. The results of the carried out experiments verified the correctness of earlier theoretical estimates for the operation time of pendulum bearings. The operation of pendulum bearings during the entire designed time (30–40 years) is reliably predicted.

Wear dynamics of fragments in the lower part of a fuel assembly with unattached rods

The dynamic characteristics and wear of unattached fuel rods in the lower supporting lattice are investigated. The vibrational eigenfrequencies and dynamic rigidity of the fuel rods in different configurations are determined. The vibrational wear at contact between the fuel rods and the spacing elements is studied.

Friction of fuel-rod casings and spacers in the pile of VVER reactors

Frictional tests of fuel-rod casings and spacing cells are conducted in various conditions. The frictional coefficients are determined for different loads. The influence of factors such as vibration, the contact load, the sample speed, the atmosphere, and the temperature is considered.

Seismic stability tests for models of fuel assemblies

A procedure and results of seismic stability tests of full-scale models for fuel assemblies of the water-water energetic reactor VVER-1000 are presented. In the course of tests, kinematic loading of fuel assembly supports has been carried out in accordance with accelerograms of the motion of fuel assembly supports during an earthquake, which was obtained by computational methods. Based on the results of measurements of the vibrational response of fuel assemblies, transfer characteristics between the response of fuel assemblies and applied action (support acceleration) are determined. The lack of a resonant response of fuel assemblies at seismic loads is found.