scholarly journals ANALYSIS OF HYSTERETIC RESPONSE OF GLASS INFILLED WOODEN FRAMES

2014 ◽  
Vol 20 (4) ◽  
pp. 600-608 ◽  
Author(s):  
David Antolinc ◽  
Vlatka Rajčić ◽  
Roko Žarnić

The idea of the present study is to determine the performance of timber-glass hybrid shear wall exposed to monotone and cyclic horizontal in-plane load at the level of story height which is simulation of situation during earthquake or wind load. Fourteen quasi-static in-plane racking tests of shear wall specimens have been conducted where the specimens are composed of laminated timber frame and heat strengthened laminated glass panels, which are adhesive less, connected to wooden frame with friction only. For the evaluation of the experimental results the software (HYSPA+) was developed which is giving the information on normalised stiffness degradation and equivalent viscous damping coefficient based on the in-plane hysteresis response. The results are showing that described structural components are ductile with relatively high potential for dissipating of induced energy due to friction connection of glass panel and wooden frame. Observed damages were concentrated in timber frame joints, while glass panels remained entirely undamaged. In continuation of development of glass infilled wooden frames the configuration of frame joints will be modified to achieve its higher load bearing capacity and lower deformability.

1990 ◽  
Vol 6 (1) ◽  
pp. 1-14 ◽  
Author(s):  
S. A. Adham ◽  
V. Avanessian ◽  
G. C. Hart ◽  
R. W. Anderson ◽  
J. Elmlinger ◽  
...  

Experimental investigations were conducted to evaluate the lateral load-deflection characteristics of lightgage steel stud/gypsum wallboard panel combinations subjected to lateral cyclic loads. In all, six 8′ × 8′ specimens were tested. A reasonable one-to-one correspondence between the strap area increase and the increase in the contribution from the strap to the overall loadcarrying capacity of the panel at intermediate and high drift ratios was observed. The panel lateral stiffness for a given stabilized cycle degraded by about 7% to 15% as compared with the lateral stiffness of the corresponding virgin cycle. Lateral stiffness degradation increased as the drift ratios became larger. The energy dissipation ability of the panels in the stabilized cycle was about 60% of the virgin cycle. An average value of equivalent viscous damping for all the cycles based on panel hysteretic behavior was about 12%.


2021 ◽  
Vol 1203 (2) ◽  
pp. 022079
Author(s):  
Michaela Zdražilová ◽  
Zdeněk Sokol ◽  
Martina Eliášová

Abstract Glass is a very attractive material for contemporary architecture. The trend is to achieve a maximum transparency of structures; therefore it becomes common to use glass as a material for load-bearing structural elements. Glass facades, roofs, beams or columns are widely used in buildings. The problematic part of a glass structure design is the connection between the glass pieces or between the glass elements and substructures from another material (e.g. steel, concrete etc.). The connection must be capable of bearing the stresses performing during the lifetime period and it should be as unobtrusive as possible at the same time. The ongoing research at the Faculty of Civil Engineering of the Czech Technical University in Prague is focused on an embedded laminated point connection for glass structures. Within this research, the real-scale glass panels were tested. The samples consisted of two glass plies bonded with the EVA foil. For the undrilled ply, the float glass was used in all cases. The thermally toughened or the heat strengthened glass was used for the pre-drilled ply. There was one embedded steel countersunk bolt with HDPE liners placed in each corner of the sample. During the experiment, the samples were horizontally placed using the embedded bolts. The load-bearing capacity of the six tested specimens was determined. The load was applied in several loading and unloading cycles until the collapse of the first embedded connection. If the glass panel failed before the connection, the sample was completely unloaded and then the load was gradually increasing until the collapse of the connection. Vertical deflection and the stresses at two different points were measured during the loading cycles. The humidity and the temperature were also monitored. The experiment showed the way of collapse and a short-term load-bearing capacity of a laminated glass panel with four embedded point connections.


Author(s):  
Kai Feng ◽  
Xueyuan Zhao ◽  
Zhiyang Guo

With increasing need for high-speed, high-temperature, and oil-free turbomachinery, gas foil bearings (GFBs) have been considered to be the best substitutes for traditional oil-lubricated bearings. A multi-cantilever foil bearing (MCFB), a novel GFB with multi-cantilever foil strips serving as the compliant underlying structure, was designed, fabricated, and tested. A series of static and dynamic load tests were conducted to measure the structural stiffness and equivalent viscous damping of the prototype MCFB. Experiments of static load versus deflection showed that the proposed bearing has a large mechanical energy dissipation capability and a pronounced nonlinear static stiffness that can prevents overly large motion amplitude of journal. Dynamic load tests evaluated the influence of motion amplitude, loading orientation and misalignment on the dynamic stiffness and equivalent viscous damping with respect to excitation frequency. The test results demonstrated that the dynamic stiffness and damping are strongly dependent on the excitation frequency. Three motion amplitudes were applied to the bearing housing to investigate the effects of motion amplitude on the dynamic characteristics. It is noted that the bearing dynamic stiffness and damping decreases with incrementally increasing motion amplitudes. A high level of misalignment can lead to larger static and dynamic bearing stiffness as well as to larger equivalent viscous damping. With dynamic loads applied to two orientations in the bearing midplane separately, the dynamic stiffness increases rapidly and the equivalent viscous damping declines slightly. These results indicate that the loading orientation is a non-negligible factor on the dynamic characteristics of MCFBs.


2015 ◽  
Vol 138 (2) ◽  
Author(s):  
Kai Feng ◽  
Yuman Liu ◽  
Xueyuan Zhao ◽  
Wanhui Liu

Rotors supported by gas foil bearings (GFBs) experience stability problem caused by subsynchronous vibrations. To obtain a GFB with satisfactory damping characteristics, this study presented a novel hybrid bump-metal mesh foil bearing (HB-MMFB) that consists of a bump foil and metal mesh blocks in an underlying supporting structure, which takes advantage of both bump-type foil bearings (BFBs) and MMFBs. A test rig with a nonrotating shaft was designed to estimate structure characterization. Results from the static load tests show that the proposed HB-MFBs exhibit an excellent damping level compared with the BFBs with a similar size because of the countless microslips in the metal mesh blocks. In the dynamic load tests, the HB-MFB with a metal mesh density of 36% presents a viscous damping coefficient that is approximately twice that of the test BFB. The dynamics structural coefficients of HB-MFBs, including structural stiffness, equivalent viscous damping, and structural loss factor, are all dependent on excitation frequency and motion amplitude. Moreover, they exhibit an obvious decrease with the decline in metal mesh density.


Author(s):  
Marcin Kozłowski

Current standards and glass codes of design practice require that glazing used in architectural applications has to be resistant to, in addition to typical loads, also accidental events, in particular human impact, without showing damage that is disproportionate to the original cause. A case study was performed of an indoor glass lantern in a public building made from slender two-side supported glass panels with a complex geometry (36 ventilation holes). The paper provides structural assessments and results of in-situ experiments including static loading and soft body impact. Results from numerical simulations of impact loading on the glass panels complementing the experimental results are also presented.


2018 ◽  
Vol 8 (12) ◽  
pp. 2398 ◽  
Author(s):  
Shunsuke Nansai ◽  
Keichi Onodera ◽  
Prabakaran Veerajagadheswar ◽  
Mohan Rajesh Elara ◽  
Masami Iwase

Façade cleaning in high-rise buildings has always been considered a hazardous task when carried out by labor forces. Even though numerous studies have focused on the development of glass façade cleaning systems, the available technologies in this domain are limited and their performances are broadly affected by the frames that connect the glass panels. These frames generally act as a barrier for the glass façade cleaning robots to cross over from one glass panel to another, which leads to a performance degradation in terms of area coverage. We present a new class of façade cleaning robot with a biped mechanism that is able overcome these obstacles to maximize its area coverage. The developed robot uses active suction cups to adhere to glass walls and adopts mechanical linkage to navigate the glass surface to perform cleaning. This research addresses the design challenges in realizing the developed robot. Its control system consists of inverse kinematics, a fifth polynomial interpolation, and sequential control. Experiments were conducted in a real scenario, and the results indicate that the developed robot achieves significantly higher coverage performance by overcoming both negative and positive obstacles in a glass panel.


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