In this study, the progressive collapse resistance of a two-story steel moment frame was investigated after sudden removal perimeter column in first floor through an experimental study. Two finite-element models with and without concrete slabs were developed compared results. The results indicate that numerical model agrees well experiment play significant role during process load redistribution. After column, partial loads previously carried by removed transferred to its adjacent columns...

A tuned liquid damper (TLD), which consisted of two-layer hemispherical containers, partially filled with water, was investigated as a cost-effective method to reduce the wind-induced vibration wind turbines. 1/20 scaled test model designed investigate its performance on shaking table. Three groups equivalent ground accelerations were inputted simulate dynamic response under different load cases. The influence rotors and nacelle assumed be concentrated tip mass. series free forced...

Summary The prestressed anchor bolt system is a reasonable connection mode between the upper steel tower and bottom concrete foundation for multi‐megawatt wind turbines. This with forged flanges has similar form to high‐strength tubes tower. However, their mechanical performances have great difference because of influence stiffness anchorage zone in foundation. Based on Petersen's method, engineering calculation method turbine derived. tensile force bolt, clamping base are all deduced...

Abstract The two-dimensional edge plasma code SOLPS-ITER have been used to study the hydrogen isotope effect on divertor detachment onset for (H), deuterium (D), and tritium (T) based EAST conditions. Results prove that H with a lighter mass has stronger ability penetrate into core than D T, resulting in higher density lower SOL. If line-averaged electron is selected characterize onset, strongly dependent measurement chord location which determines contribution of density. modeling results...

A spherical tuned liquid damper (TLD) is proposed as a cost-effective method to reduce the earthquake-induced vibration of wind turbines. 1/20-scale test model was designed investigate its performance controlling structural vibration. series free and forced experiments with different water depths in hemispherical containers were performed on shaking table. Three measured ground acceleration-time histories, including El Centro NS, EW Tianjin EW, selected verify effectiveness TLD suppressing...

Summary The steel–concrete hybrid wind turbine tower is characterized by the lower part of traditional steel tubular replaced with concrete segment. lateral stiffness will be improved obviously, and then, excessive vibration can solved effectively. Based on genetic algorithm, an optimization program built to consider influence materials, labor, machinery, transportation construction cost a for 2.0‐MW hub height 120 m, in which initial segment 32 m. During process, design requirements...

In this study, the contribution of horizontal bracing to resistance a steel moment frame against progressive collapse was investigated using alternate path method. Nonlinear dynamic analyses two models with and without braces were carried out in various cases. The nonlinear analytical results indicated that compared model braces, displacements rotation angles much smaller because tie provided by at top story. It observed could transfer vertical loads originally removed column adjacent...

Based on the work principles of tuned mass damper and particle damper, an innovative double-response combined with is proposed to suppress wind-induced vibrations wind turbine towers in this study. The was designed, fabricated, installed top platform onshore a rated power output 1.5 MW. site measurements were carried out investigate its control effectiveness. dynamic responses under both emergency shutdown case normal operation obtained by acceleration transducers wall near tower. Because...

As the size of wind turbine grows, cost commonest tubular structural system will also increase because increasing transportation, assembly, erection and servicing. A lattice-tubular hybrid system, which is composed a four-angle cross-shaped lattice structure at bottom top, proposed for large systems. The welding processes can be totally avoided fatigue strengths effectively improved all members assembled by bolts in site after cutting drilling factory. ultimate bearing capacities combined...

Summary More and more prefabricated steel–concrete hybrid wind turbine towers have been built because of their better lateral stiffness than those the full steel towers, in which epoxy resin joints are commonly adopted at horizontal joint between two ring units for improving erection speed. In fact, designed same way as dry due to very thin thickness layer, only acts a leveling blanket sealer jointing compensates unevenness contact surface units. The current design method resistance...

A basin tuned and particle damper is proposed to reduce the wind-induced vibration for wind turbine tower. shaker test platform was introduced simulate first-order of tower under emergency shutdown case. The swing frequency can be adjusted by changing its suspension length. different intensity system considered setting initial displacement on platform. series tests were carried out study influence parameters damping effect. response measured laser sensor. whole process recorded a camera...

The steel–concrete hybrid wind turbine tower is characterized by the concrete tubular segment at lower part and traditional steel upper part. Because of great change mass stiffness along height connection segment, its dynamic responses under seismic ground motions are significantly different from those tower. Two detailed finite element models a full for 2.0 MW built in same farm are, respectively, developed using software ABAQUS. response spectrum method applied to analyze action effects...

LLC resonant DC-DC converter has been widely used in high power density and efficiency applications.Pulse frequency modulation (PFM) is commonly applied due to its wide soft-switching range.In some special cases, phase shift (PSM) widen voltage regulation range, improve light-load efficiency, or implement a soft start-up process.Because with 2 control degrees of freedom (2DOFs), switching duty ratio, unified analysis optimization for 2DOFs desired.This paper makes an effort present time...

High-power applications of cascaded multilevel inverter to active power filters (APF) is hindered by the problem keeping capacitor voltage balance while retaining good filtering performances. This paper proposes a novel control technique with closed-loop harmonic compensation for used in high-power APF. The proposed method not only maintains but also has performances, which suits APF based on five-level and more level inverters. steady state dynamic experiment waveforms obtained from...

Summary This paper proposes a technique of generating turbulent wind velocities on large horizontal‐axis turbine systems under different operating conditions. The rotational sampling effect, vertical shear and coherence between at blades the tower were taken into account. Coordinate system time series certain discrete points plane is generated by hybrid weighted amplitude wave superposition proper orthogonal decomposition (POD) methods. POD eigenmodes after updating locations calculated...

The seismic behaviors of different steel beam-to-column moment connections have been fully described by many researchers. Some researchers focus on their progressive collapse resistances static and rate-independent analyses. However, the influence strain-rate effect should not be neglected when main column is removed instantaneously in a analysis. In this paper, performances typical with details, including welded unreinforced flange-bolted web (WUFB), cover plated flange (WCPF), reduced beam...

An embedded-ring foundation connected to the steel tower above it by inserting ring into concrete is a traditional and widely used form for wind turbine towers. insufficiently embedded depth of leads stress concentration on corner windward-side T-shaped plate. A damage zone develops, leading gaps between decline in restrain stiffness pier, which induces larger horizontal displacement decrease natural frequency system. To improve fatigue life around under precondition not destroying original...

The embedded-ring wind turbine foundations were widely applied in the early development stage of power industries because its properties such as easy installation and adjustment. However, different damages occurred on some recent years. Based common damage phenomena foundations, structural defects mechanisms are analyzed a gradual way. Cheese head studs proposed to be welded lateral wall steel ring strengthen connection between foundation concrete. pier is elevated 1 m increase embedded...