Peak Sliding Demands on Unanchored Equipment and Contents in Base-Isolated Buildings under Pulse Excitation

Seismic assessment approaches for mass‐dominant sliding contents: The case of storage racks

“…Additional parameters such as the pulse period of pulse-like ground motions, or the dominant period of the excitation in general, may be influential when considering the response under a specific record. 19 Still, they are not considered as they cannot be easily introduced in practical applications. Essentially, the sliding displacement, and consequently the 𝜉 𝑒𝑞 , of a 2DOF system with 𝑚 = 𝑀, period 𝑇, and friction constant 𝜇, is tested against the single variable 𝑆𝑎(𝑇)∕𝜇 that was selected as the normalized Intensity Measure (IM) for the effect of pallet sliding, with 𝑆𝑎(𝑇) being the spectral acceleration of a linear elastic oscillator with period equal to 𝜏.…”

“…In general, the higher the period of the 2DOF system, the greater the sliding. 21 Indeed, it has been shown analytically that the maximum displacement of a sliding mass depends approximately on the square of the dominant period of the excitation, 19 which for sliding of contents it is practically equivalent to the period of the supporting rack that dominates the narrow-band floor/level excitation. 22…”

Dynamics of a sliding‐rocking block considering impact with an adjacent wall

“…Shake table test studies of typical life‐science‐laboratory equipment (Hutchinson and Chaudhuri; Konstantinidis and Makris) have demonstrated that this type of equipment can be idealized as planar rigid bodies resting on a surface described by a Coulomb friction model. The sliding response of a rigid block, which represented building content, subjected to ground and floor excitation has been studied analytically at various levels by Choi and Tung, Lopez Garcia and Soong, Chaudhuri and Hutchinson, Konstantinidis and Makris, Voyagaki et al, Konstantinidis and Nikfar, Lin et al, Nikfar and Konstantinidis, and references therein. Nikfar and Konstantinidis investigated the effect of the stick‐slip phenomenon on the sliding response of rigid blocks using a Stribeck friction model.…”

Near‐fault acceleration pulses and non‐acceleration pulses: Effects on the inelastic displacement ratio

“…Specifically, the seismic damage within a near-fault region is often caused during a few cycles of severe inelastic deformation that coincides with large amplitude velocity pulses in the ground motions. [11][12][13] From the engineering perspective, the effects of pulse-like ground motions on various structures have been investigated, including idealized single (or multi)-degree-of-freedom (SDOF) systems, 14,15 seismically base-isolated structures, 16,17 bridge structures, 18,19 and some other special buildings or elements. 2 Previous studies confirmed that key features of the velocity pulse, eg, amplitude, predominant period, and the pulse shape, play important roles in affecting the structural response and are primarily affected by the earthquake source characteristics, location of the recording station relative to the fault rupture as well as the site effects.…”

“…From the seismological perspective, numerous studies have been carried out by using analytical models to characterize the velocity pulses, [4][5][6] accounting for the pulse effects in seismic hazard analysis, 7,8 simulating pulse-like ground motions using stochastic approaches, 9,10 and classifying velocity pulses through automated algorithms. [11][12][13] From the engineering perspective, the effects of pulse-like ground motions on various structures have been investigated, including idealized single (or multi)-degree-of-freedom (SDOF) systems, 14,15 seismically base-isolated structures, 16,17 bridge structures, 18,19 and some other special buildings or elements. [20][21][22][23] A common finding in the above studies is that the effects of pulse-like ground motions significantly depend on the relative characteristics of the velocity pulse and the dynamic properties of the structure.…”