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Based on Kogut and Etsion's finite element contact model (KE model) and citing the hardness geometric limit proposed by Jackson et al., the deformation stage of an asperity is re-divided, and a normal contact stiffness model of joint interface is established by using a statistical theory. The simulation results show that the normal contact stiffness of joint interface is a nonlinear function of the mean surface separation and decreases with the increase of the mean surface separation under different plasticity indexes. By comparing the normal contact stiffness model of joint interface considering hardness changes with the normal contact stiffness model of joint interface without considering hardness changes, it is found that, with the increase of the plasticity index, the difference between calculated results becomes larger. [ABSTRACT FROM AUTHOR]

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This paper reported an experimental and numerical study of a novel brace-type hybrid damper composed of steel slit plates enhanced by the friction mechanism. A test programme including six proof-of-concept specimens was carried out. The test results showed that the specimens exhibited multiple yielding stages, and the hysteretic response curves of the specimens were dependent on geometric configurations of the steel slit plates and the clamping force of bolts. The expected energy dissipation sequence accompanied by excellent ductility of the novel hybrid damper specimens was confirmed. The ploughing effect phenomenon between the friction interfaces as evidenced by the wear of the steel plates and increasing friction force was confirmed, which contributed to enhanced friction energy dissipation of the dampers under cyclic loadings. Then, a numerical investigation was conducted to take insights into the resisting mechanism of the specimens. The adequacy of the finite element modelling techniques was justified by a good correlation between test responses and numerical simulations. The test and numerical studies demonstrated that the energy dissipation sequence as a result of the hybrid energy dissipation mechanism contributed to improving the energy dissipation capacity and ductility of the steel slit plates. To facilitate the practical design of the novel hybrid dampers, a theoretical prediction model enabling quantification of critical mechanical quantities of the novel hybrid damper was developed, and the sufficiency of the design model was justified by comparison among the test responses, numerical results, and design predictions. • A novel brace-type hybrid damper composed of steel slit plates enhanced by the friction mechanism was proposed. • Six damper specimens were designed and physically tested. • Proposed hybrid damper can achieve excellent energy-dissipation capacity and ductility. • The resisting mechanism of the hybrid damper was comprehensively numerical studied. • A theoretical prediction model of the novel hybrid damper was developed. [ABSTRACT FROM AUTHOR]

The reliability and service life of power cables is closely related to the cable ampacity and temperature rise. Therefore, studying the temperature field distribution and the cable ampacity is helpful to improve the construction guidelines of cable manufacturers. Taking a 8.7/15 kV YJV 1 × 400 XLPE three-loop power cable as the research object, cable temperature is calculated by IEC-60287 thermal circuit method and numerical simulation method, respectively. The results show that the numerical simulation method is more in line with the actual measured temperature, and the relative error is only 0.32% compared with the actual measured temperature. The temperature field and air velocity field of cluster cables with different laying methods are analyzed by finite element method. The corresponding cable ampacity are calculated by secant method. The results show that when the cable is laid at the bottom of the cable trench, the cable current is 420 A, which is 87.5% of the regular laying. Under irregular laying mode, the temperature of cable is higher than that of regular laying mode and the cable ampacity is lower than that of regular laying mode. At the same time, a multiparameter online monitoring system is developed to online monitor the temperature, water level and smoke concentration of the cable. [ABSTRACT FROM AUTHOR]

Driven by the demand of producing novel seismic resilient structures, this study focused on steel moment resisting frames equipped with superelastic shape memory alloy (SMA) connections in the self-centring energy dissipation bays, and the emphasis was given to a direct-iterative design method for performance-based-plastic-design of the system under earthquake motions. Utilising the equivalent single-degree-of-freedom (SDF) oscillator which may reasonably quantify the dynamic responses of a multi-storey structure, an inelastic structural seismic demand model motivated by nonlinear spectral analyses was developed, and the statistic features were accounted. As the theoretical basis of the design philosophy, the seismic energy equilibrium equation of the structure was correlated with structural arrangement and earthquake motion characteristics. Then, a stepwise plastic design methodology enabling practising engineers to search for a feasible design strategy was proposed. Three prototype structures were developed following the proposed method, and finite element models of the systems were developed. The adequacy of the modelling techniques was verified by the test database, and the sufficiency of the hysteretic model of the structure was also justified. The seismic responses of the prototype structures were estimated by nonlinear static and dynamic analyses. The analysis data pool confirmed that the prototype structures were able to achieve the damage-control objective by limiting the maximum interstorey drifts below the prescribed deformation threshold, and inelastic actions were concentrated in the self-centring energy dissipation bays. [Display omitted] • Probabilistic energy factor demand spectra for self-centring system under near-field earthquake motions was developed. • A performance-based-plastic-design methodology was developed from a statistic perspective. • The sufficiency of the proposed design methodology was confirmed. [ABSTRACT FROM AUTHOR]

A full-scale test programme for reinforced single-coped beams with slender web (RSCBSW) connections is reported in this paper. The test matrix included reinforcement types and coping details. The adequacy of the two reinforcement strategies was confirmed by the test results, and it was found that all specimens failed by buckling of the plate girder section away from the coped region. The test results also showed that for the reinforcement strategy with double full-depth transverse stiffeners, the decrease in the strength of the specimen in the post-ultimate stage was comparatively less significant compared with the specimens strengthened by a single full-depth transverse stiffener, and this phenomenon was more apparent in the case of a deep cope. Subsequently, finite element (FE) models of test specimens were developed to replicate the behaviour of the RSCBSW connections, based on which a parametric study covering a wider range of factors was conducted. The numerical results further confirmed the effectiveness of the reinforcement strategy, and no models experienced local web buckling in the vicinity of the cope. The available design equations to quantify the buckling resistance of the plate girders were applied to the test specimens and the numerical database. It was found that for cases with double full-depth transverse stiffeners, the design predictions were generally conservative. In contrast, unsafe predictions were obtained for several cases with a deep cope which was enhanced by a single full-depth transverse stiffener. [Display omitted] • Reinforcement strategies for enhancing single-coped beam with slender web connections were experimentally examined. • A parametric study covering a wider range of factors was conducted. • The effect of the longitudinal stiffener was confirmed. • The design equations for quantifying the resistance of the specimens were revisited. [ABSTRACT FROM AUTHOR]