Force transfer mechanism on fastener section of mechanically anchored waterproofing membrane roofs under wind pressure during typhoons

Miyauchi, Hiroyuki; Katou, Nobuo; Tanaka, Kyoji

doi:10.1016/j.jweia.2011.09.006

Cited by 11 publications

(6 citation statements)

References 4 publications

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“…It can be seen that horizontal forces nearly equal to or larger than the vertical ones are generally generated on the fasteners. Such an experimental result is consistent with the finding of Miyauchi et al [30] in the field observation made on a full-scale test building during a typhoon. In the case of buildings with parapets, the mean value of F x is generally small in magnitude.…”

Section: Resultssupporting

confidence: 92%

“…Following significant damage to waterproofing systems caused by strong winds of Typhoon No. 18 of 2004 in Japan, Miyauchi et al [30], [31] carried out extensive research on the wind-induced behavior and wind-resistant performance of mechanically attached single-ply membrane roofing systems. First, they carried out a field measurement of wind pressures and wind-induced responses (membrane deformations and fastener loads) of a roofing system installed on a full-scale flat-roofed test building without parapets, 6 m long, 6 m wide, and 3 m high, during a typhoon.…”

Section: Figure 2 Deformation Of Waterproofing Membrane and Forces Acting On The Fastenermentioning

confidence: 99%

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Wind-Induced Dynamic Behavior of Mechanically Attached Single-Ply Membrane Roofing Systems Installed on Flat Roofs

Uematsu

Sugiyama

Usukura

2021

Engineering Science & Technology

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The present paper investigates the wind-induced dynamic behavior of a mechanically attached single-ply membrane roofing system installed on flat roofs of middle-rise and high-rise buildings with or without parapets. First, the wind pressure distributions on the roof were measured in a turbulent boundary layer. The results indicate that the parapets affect the wind pressure distributions significantly. Very large peak suctions are induced near the windward corner of the roof in an oblique wind in the case of a building without parapets. Then, we have developed a test method for evaluating the wind-resistant performance of the roofing system using three Pressure Loading Actuators (PLAs) and a chamber to which a full-scale specimen is attached. In the experiments, the chamber was divided into three spaces by using thin silicon sheets. The PLAs generated different fluctuating pressures in these spaces using the time history of wind pressure coefficients measured at three points near the windward corner of the roof in an oblique wind. We measured the membrane deformations and the wind forces acting on the fasteners connecting the membrane with the structural substrate. The results indicate that horizontal forces nearly equal to or larger than the vertical ones are generated on the fasteners, which may cause pulling out of fasters more easily. The failure mode was found to be different from that obtained from a ramped pressure loading test. We have also developed a model of finite element analysis, which was validated by an experiment. The results of analysis for a wide area of roofing system indicate that relatively large horizontal forces may be generated on the fasteners in the field region of the roof for buildings with parapets.

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Section: Resultssupporting

confidence: 92%

Section: Figure 2 Deformation Of Waterproofing Membrane and Forces Acting On The Fastenermentioning

confidence: 99%

Wind-Induced Dynamic Behavior of Mechanically Attached Single-Ply Membrane Roofing Systems Installed on Flat Roofs

Uematsu

Sugiyama

Usukura

2021

Engineering Science & Technology

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“…It was found that horizontal forces nearly equal to or larger than the vertical ones were generated on the fasteners when the PV panels were not installed. This feature corresponds well to the findings of Miyauchi et al [9,10] and Sugiyama et al [11]. When the PV panels were installed, the values of F V and F H were reduced significantly, except for F H at A-1.…”

Section: Resultssupporting

confidence: 91%

“…This type of loading generates only vertical forces on the fasteners. Miyauchi et al [9] carried out a field measurement of wind pressures and wind-induced responses (membrane deformations and loads on fasteners) of a mechanically attached single-ply membrane roofing system installed on a full-scale flat-roofed test building without parapets during a typhoon. They found that fasteners located near the windward corner were subjected to horizontal forces as large as vertical ones.…”

Section: Introductionmentioning

confidence: 99%

The Benefit of Horizontal Photovoltaic Panels in Reducing Wind Loads on a Membrane Roofing System on a Flat Roof

Uematsu

Yambe

Watanabe³

et al. 2021

Wind

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The present paper proposes a measure for improving the wind-resistant performance of photovoltaic systems and mechanically attached single-ply membrane roofing systems installed on flat roofs by combining them together. Mechanically attached single-ply membrane roofing systems are often used in Japan. These roofing systems are often damaged by strong winds, because they are very sensitive to wind action. Recently, photovoltaic (PV) systems placed on flat roofs have become popular. They are also often damaged by strong winds directed onto the underside, which cause large wind forces onto the PV panels. For improving the wind resistance of these systems, we proposed to install PV panels horizontally with gaps between them. Such an installation may decrease the wind forces on the PV panels due to the pressure equalization effect as well as on the waterproofing membrane due to the shielding effect of the PV panels. This paper discusses the validity of such an idea. The pressure on the bottom surface of a PV panel, called the “layer pressure” here, was evaluated by a numerical simulation based on the unsteady Bernoulli equation. In the simulation, the time history of the external pressure coefficients, measured at many points on the roof in a wind tunnel, was employed. It was found that the wind forces, both on the PV panels and on the roofing system, were significantly reduced. The reduction was large near the roof’s corner, where large suction pressures were induced in oblique winds. Thus, the proposed method improved the wind resistance of both systems significantly.

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“…Based on overviews of disaster prevention of membrane structures, it can be seen that the first two aspects have been deeply studied by many researchers for many years, and many literatures have been published. [3][4][5][6] However, as key issues of safety evaluation, the research on the structural resistance lags behind other aspects, due to the complexity of material response and lack of accurate research tools. Among various issues in analyzing the dynamic response of membrane structures, the non-linear dynamic effect of materials and structures are the basis of solving other key issues.…”

mentioning

confidence: 99%

Experimental analysis of tensile behaviors of polytetrafluoroethylene-coated fabrics subjected to monotonous and cyclic loading

Zhang

et al. 2013

Textile Research Journal

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This paper presents the tensile behaviors of polytetrafluoroethylene (PTFE)-coated fabrics subjected to monotonous and cyclic loading. First, uniaxial tensile tests are conducted to study the uniaxial cyclic behaviors, in which the effects of stress amplitude and temperature on the fabrics are studied. Then, biaxial tests are carried out to analyze the biaxial cyclic behaviors with different stress ratios. Finally, the mechanical properties of PTFE-coated fabrics without initial loading and after cyclic loading are compared. The results show that the tensile behaviors of PTFE-coated fabrics are asymmetric and affected obviously by loading protocols, which are concerned with the woven structure of substrate and properties of yarns. After cyclic loading, the significant stiffness strengthening and the linearity of tensile behaviors becomes obvious, while the discrepancy between the elastic modulus of the warp and the weft decreases. Compared with the new material without initial loading, the material tensile strength after cyclic loading remains almost unchanged, which may be related with fewer cycle numbers. The tensile behaviors under cyclic loading are mainly related with stress amplitude, temperature and woven structure of substrate. With temperature increasing, the degree of stiffness strengthening after cyclic loading increases. The effect of loading history on the mechanical properties of PTFE-coated fabric is obvious, and different constitutive constants should be conducted regarding different design stages.

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Force transfer mechanism on fastener section of mechanically anchored waterproofing membrane roofs under wind pressure during typhoons

Cited by 11 publications

References 4 publications

Wind-Induced Dynamic Behavior of Mechanically Attached Single-Ply Membrane Roofing Systems Installed on Flat Roofs

Wind-Induced Dynamic Behavior of Mechanically Attached Single-Ply Membrane Roofing Systems Installed on Flat Roofs

The Benefit of Horizontal Photovoltaic Panels in Reducing Wind Loads on a Membrane Roofing System on a Flat Roof

Experimental analysis of tensile behaviors of polytetrafluoroethylene-coated fabrics subjected to monotonous and cyclic loading

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