Enhancing seismic resilience using truss girder frame systems with supplemental devices

The energy factor of systems considering multiple yielding stages during ground motions

“…Specifically, an energy factor considering the interaction of ground motion properties and systematic nonlinearity was introduced to consider the energy equilibrium. Based on this modification, extensive investigations have been made, and the derived energy factor has been applied in plastic design and evaluation of various structures [8][9][10][11][12][13][14]. With the energy factor and the classic Housner's equation, the demand during ground motions can be computed to design or evaluate the seismic capacity of the system.…”

“…Jiang et al [9] used the energy factor to determine the energy demand of systems and developed an energy-based multimode pushover analysis procedure. It should be noted that although these procedures are rational as they lead to reasonable accuracy, they were established on the elasto-plastic idealization which might conceal some real features of systems, especially for some innovative structures showing multiple yielding stages [11][12][13][15][16][17][18]. In this regard, it is more instructive to involve the yielding stages and to evaluate their effects when constructing the energy-balance equation.…”

“…The energy factor essentially denotes the ratio of the energy absorbed by an inelastic system to that of the corresponding elastic system under monotonic loading. The cumulative effect is indirectly considered, and this equation has been applied in extensive research works [7][8][9][10][11][12][13][14], which is considered to be rational. Practically, systems may exhibit the feature of multiple yielding stages as shown in Fig.…”

“…1, and this feature is remarkable especially for systems such as the damage-control systems with energy dissipation devices [15][16][17] and recently proposed innovative systems considering the performance-based design [11][12][13][14]18]. In essence, this feature is caused by yielding sequences of components in systems and has been observed by the research works of specific systems [11][12][13][15][16][17][18]. In this context, the ductility factor defined as the ratio of the maximum displacement to the first yield displacement [9,11,13] might only evaluate the maximum inelastic deformation, and the influence of the multiple yielding stages is neglected.…”

“…In essence, this feature is caused by yielding sequences of components in systems and has been observed by the research works of specific systems [11][12][13][15][16][17][18]. In this context, the ductility factor defined as the ratio of the maximum displacement to the first yield displacement [9,11,13] might only evaluate the maximum inelastic deformation, and the influence of the multiple yielding stages is neglected. It is also noted that the definition of ductility may be various in different research works and codes [19,20], but it is, in general, an equivalent index that cannot take the yielding stages into consideration explicitly.…”