Investigating the vibration properties of integrated ceiling systems considering interactions with surrounding equipment

In a conventional wall frame system, shear walls typically exhibit less deformation capacity under earthquakes than the frame. In this study, an innovative prefabricated slotted composite shear wall was proposed, abbreviated as CDSW.Featured with concrete-filled-tube (CFT) wall segments, I-shaped steel connectors, vertical slots and bolted connections with the frame, the CDSW has significantly improved deformation capacity, energy dissipation capacity and construction efficiency compared with conventional shear walls. Its seismic behaviors were investigated through applying quasi-static cyclic loads, where the specimen exhibited satisfactory cyclic response. Based on the test results, finite element analysis (FEA) models were established to validate the test results, and 12 parametric FEA cases were conducted to optimize the parameters of CDSWs. A new design method of a CDSW with highly accurate formulas was proposed based on a new parameter termed as equivalent stiffness ratio (ESR). With ESR, the stiffness and internal force of a CDSW can be obtained with satisfactory precision.Based on the analytical result and the new design formulas, it can be concluded that the ESR between 0.706 and 1.25 is recommended for practical engineering applications, which took into consideration the governing factors of yield and peak strength, stiffness, deformation capacity and energy dissipation. Additionally, the installation of the upper and lower sets of connectors at about 40% and 60% of the height of CDSW is suggested, respectively. K E Y W O R D Sdesign approach, equivalent stiffness ratio, FEM analysis, prefabricated structure, slotted shear wall INTRODUCTIONShear walls are commonly adopted to incorporate with frames in forming the wall-frame dual structural system to achieve seismic resilience. Considerable shear wall stiffness and strength can be achieved through carefully selected proportioning and detailing. However, due to the low aspect ratios, conventional shear walls often exhibit less deformation capacity than the frame during earthquakes in a typical dual system. Accordingly, "ductile walls" 1 are required to improve the "ductility" of the system. Ji et al 2 proposed a composite shear wall which consists of outer steel plates connected with tie

Section: Design Approach Of a Cdswmentioning

confidence: 99%

Parametric analysis and new design formulas of a prefabricated energy‐dissipating composite slotted shear wall

Shen

Pan

et al. 2021

“…Two‐elevation ceiling systems often exist because of the inevitable requirements of installing air ducts and piping 24 . After installing the support grid systems, which are made of main and cross runners, the inclined members are temporarily deployed between the two elevations for positioning.…”

Section: Experimental Programmentioning

confidence: 99%

“…Two-elevation ceiling systems often exist because of the inevitable requirements of installing air ducts and piping. 24 After installing the support grid systems, which are made of main and cross runners, the inclined members are temporarily deployed between the two elevations for positioning. The main runners at the higher elevation first extend over a certain distance, and then the inclined members made of U-38 × 12 × 1.6 are employed to connect these members with the main runners at the lower elevation.…”

Section: Two-elevation Ceiling Specimenmentioning

confidence: 99%

“…The specimen studied in this paper includes two light fixtures and two ACs with two different suspension lengths, that is, 1375 mm in the lower elevation and 920 mm in the higher elevation, labeled, henceforth, as AC-920, AC-1375, light-920, and light-1375. A clearance existed between the equipment and the surrounding ceiling panels but friction exists between the cover panel of electrical equipment 24 (B) Zoom-in on two elevations and the ceiling panel. For the suspension of electrical equipment, the L-shaped angles (L-50 × 50 × 5) were also used to adjust the distance between the vertical suspension bars and the inserted hole in the upper floor slab.…”

Section: Two-elevation Ceiling Specimenmentioning

confidence: 99%

“…The details of the stiffness calculation method for suspended electrical equipment can be found in Ref. 24. Besides the electrical equipment, three kinds of pipes for water supply, refrigeration, and drainage were installed to assess their seismic behavior in the ceiling system.…”

Section: Two-elevation Ceiling Specimenmentioning

confidence: 99%

See 2 more Smart Citations

Seismic evaluation of two‐elevation ceiling system by shake table tests

Kurata

Ikeda

et al. 2020

Self Cite

Past earthquakes highlighted the vulnerability of the suspended ceiling, especially in earthquake‐prone countries like Japan; the post‐earthquake reconnaissance showed that damage to ceiling systems led to immeasurable economic loss and disturbance of the timely rescue of casualty. The existing studies have mostly focused on the seismic performance of regular square and leveled ceilings, whereas the inevitable requirements to accommodate air ducts, nonstructural piping, and electrical equipment resulted in a two‐elevation ceiling system. This paper reports a series of full‐scale shake table tests on a typical two‐elevation ceiling system, which includes electrical equipment, piping system, and commonly used suspended ceiling structure. Experimental observations showed that the two‐elevation ceiling system performed well under earthquake excitation. No fallen panels or overall system collapse occurred during shaking. This paper discusses the effects of a temporary‐positioning‐bracing bar (TPBB) between two ceiling elevations and peripheral constraints by surrounding wall on the acceleration and displacement response and torsional behavior in the ceiling system. Then, a simplified analytical model was established and verified with the experimental response of different ceiling configurations. The test results indicated that a sufficiently strong TPBB is essential to reduce the relative displacement between two ceiling elevations, and it ensures the integrity of two ceiling elevations in the ceiling system. In conclusion, the TPBB shall remain in the ceiling system after the construction stage.

Frequency‐Sensitivity of the seismic damage to suspended ceilings

Feng

2023

Seismic damage to suspended ceilings was frequently reported even in minor to moderate earthquakes and caused problems to immediate occupancy and quick recovery of buildings. While peak floor acceleration (PFA) has been exclusively used as an intensity measure for suspended ceilings, this study introduces a shake table test on minimum subassemblies of suspended ceilings under sinusoidal excitation to critically assess the rationality of this practice. The test results show a significant frequency‐sensitivity of the ceiling damage that, depending on the dominant frequencies, an excitation of a lower PFA might cause much severer damage than that of a higher PFA. A numerical model that captures the nonlinear interaction of the individual components in a suspended ceiling, that is, the main and cross runners, ceiling panels, a hanger, and enclosure angles, is established and calibrated to simulate the frequency‐sensitive behavior observed in the shake table tests. The model is then extended for suspended ceilings of realistic dimensions. Three‐dimensional fragility spectra of suspended ceilings under sinusoidal excitations are proposed to relate the extent of seismic damage with not only the PFA but also the excitation frequency. Boundaries of damage limit states can be defined by taking two‐dimensional sections on the fragility spectra, based on which, the influence of key factors on ceiling damage characteristics is illustrated.