Curtain Wall Structure Research Articles

Construction defect identification for structural sealant by statistical driving-point accelerance

Accidental defects occur often during the construction of the structural sealant in a glass curtain wall structure. However, there are tens of thousands of glass panel units in a building, and the baseline models of different panel units are different from each other. In this paper, a two-stage construction defect identification method is proposed to identify a few units with structural sealant defect from a large number of units. In the first stage, the average driving-point accelerance (DA) was used as statistical baseline DA to calculate the accumulative difference of driving-point accelerance (ADDA). Then, the abnormal panel units are identified by the quantile estimation method. In the second stage, structural sealant construction defects are detected further by comparing the peak frequency difference between the statistical baseline DA and the abnormal DA. Several numerical examples and on-site experiments indicated that the probability density function of ADDA is agreement with the Weibull distribution, and the proposed method can effectively detect the structural sealant construction defects from many units without baseline model.

Structural behaviour of an asymptotic curtain wall stiffened with lamella couplings

Asymptotic structures are a novel construction system that allows fabrication from straight and flat lamellas, that are bent and twisted into the design shape. The challenge of this strategy is to design sufficiently slender profiles for deformation while maintaining structural stability in the curved state. This paper investigates a strategy to reinforce two parallel lamella members through timber couplings to improve their structural performance. The structural behaviour of the reinforced structure is investigated experimentally and numerically, and compared to the original design. The structural principle of coupling reinforcement is investigated for a double-lamella member under axial force, shear force, bending moment, and torsion. Results show that the structural stiffness and the load-bearing capacity of the asymptotic curtain wall under point load and wind load increase significantly if coupled. This effect can further be improved, by increasing the material stiffness, parallel offset, and the number of coupling blocks. Moreover, using a continuous coupling between the two lamellas to form a steel-timber-steel sandwich member can stiffen the asymptotic curtain wall structure by 436% under wind load, in comparison with 76% using two discrete timber couplings for each member.

Numerical study of the geometrical dimensions for glass curtain wall with an enclosed rectangular cavity

ABSTRACT To gain further insight into the thermal performance of a glass curtain wall with an enclosed rectangular cavity, a 2D mathematical model was established to analyze the characteristics of radiation and convective heat transfer in the glass curtain wall with an enclosed rectangular cavity, as well as to evaluate the effect of the glass curtain wall structure on thermal performance. The results showed that the total heat flux of the glass curtain wall with an enclosed rectangular cavity decreased at a decreasing rate with the increase in emissivity of glass. The total heat flux of the glass curtain wall with an enclosed rectangular cavity decreased with the increasing height of the enclosed rectangular cavity. At 15 mm thickness of the glass curtain wall, the total heat flux reached its minimum value and then increased with further thickeness of the enclosed rectangular cavity. In addition, the least square method was used to obtain the Nu correlation of argon with a relative deviation of less than 12% for better predicting the flow and heat transfer characteristics of argon in the glass curtain wall.

Construction technology on dismantlement and reconstruction of point supported glass curtain wall for airport terminal building

Based on the corridor channel curtain wall reconstruction project at Wuhan Tianhe airport T2-T3 terminal building, the structural system of point supported glass curtain wall with cable structure 18 years ago was analyzed, the technical difficulties of curtain wall glass panel removal and bearing cable removal were studied, and technical measures for the dismantlement and reconstruction of point supported glass curtain wall with cable structure were reasonably proposed. During the construction process of the dismantlement and reconstruction, the curtain wall structure was dynamically monitored, the deformation of the monitoring points were small, and the construction process was in a safe state. Due to the success in the dismantlement and reconstruction control technology of the point supported glass curtain wall with cable structure in this project, it not only ensured the construction safety, but also improved the construction quality, which could provide a reference for other similar projects.

Dynamic Characteristics Test and Simplified Calculation Model of Concealed Frame Panel Element

Hidden frame glass curtain walls are one of the most common curtain wall structure forms. This year, the damage identification of panel elements based on vibration has had the problem of an inconsistent calculation model. In this paper, an experimental study on the dynamic characteristics of two full-scale panel elements is carried out, and the main factors affecting the dynamic characteristics of panel elements are analyzed by using a fine finite element model, and the corresponding simplified calculation model is proposed. The experimental and numerical results show that the structural sealant and frame are the important factors affecting the dynamic characteristics of panel units of hidden frame, and the natural frequency of panel elements can be overestimated by more than 40% if a simply supported boundary is adopted. The effect of structural sealant on glass panels and the supporting frame is mainly a translational constraint. The effect of structural sealant on the rotational constraint of a glass panel can be neglected and simplified as a translational spring model. Using a shell element, a translational spring element and a beam element, respectively, the calculation error of the glass panel, structural sealant and supporting frame is about 5%, which shows good calculation accuracy.

Understanding Occupants’ Thermal Sensitivity According to Solar Radiation in an Office Building with Glass Curtain Wall Structure

The thermal comfort of occupants in the increasing number of modern buildings with glass curtain wall structures is of significant research interest. As the thermal sensitivity of building occupants varies with building features, situational factors, and the human body’s thermal balance, it is necessary to derive the comfort temperature based on field research, which was conducted in this study in a South Korean office building with a glass curtain wall structure. The influence of solar radiation on the indoor thermal environment and thermal comfort obtained by measurements and occupant questionnaires was analyzed using cumulative graphs and a sensitivity analysis. The observed changes in operative temperature over time confirmed that occupant comfort was significantly affected by the radiant temperature. Based on this result, two groups (Group A near the windows and Group B near the interior corridor) were defined for analysis. Owing to the influx of solar radiation, Group A was more sensitive to changes in the thermal environment (0.67/°C) than Group B (0.49/°C), and the derived comfort temperature for each group differed from the set temperature by approximately ±2 °C. Thus, it was confirmed that the solar radiation introduced through a glass curtain wall building has a direct impact on the indoor thermal environment and occupant comfort according to location.

Exploring the Application of the Historical and Cultural Elements of Bashu Area in Hotel Design --The Example of the Temple House in Taikoo Li, Chengdu

Regional history and culture is an important part of traditional Chinese history and culture, and the integration of regional cultural elements into hotel design is conducive to demonstrating China's cultural confidence to the world. Chengdu The Temple House applies elements of regional history and culture to the hotel's architectural design, with the renovation of the front lobby incorporating ancient buildings such as Chengdu's Daci Temple and Clerk architecture, the hotel's curtain wall structure presenting Shu brocade weaving techniques, the courtyard arrangement being a true depiction of the natural landscape of Bashu area, and the functional area decorated with silk road and bronze culture, which is an important way to inherit and promote the regional history and culture of Bashu area. However, due to a lack of experience and professional guidance in history, the innovative design of the Chengdu the Temple House suffers from high cost of construction, inconsistent cultural design styles, over-emphasis on artistic but not holistic design, and a lack of in-depth exploration of the connotations of regional history and culture. Therefore, in the future, the hotel design incorporating regional historical and cultural elements should learn from the lessons of Chengdu the Temple House, optimise the cost of building materials for the renovation of ancient buildings and the incorporation of historical elements, unify the culture of interior decoration involving style, and on the basis of harmonising the artistry and practicality of the hotel, widely develop interdisciplinary cooperation between tourism and history to deeply explore the connotation of regional historical and cultural elements in the hotel design process. This will enhance the world's understanding of Chinese regional history and culture, and open up new ideas for the transmission of traditional culture in hotel architectural design.

A Fundamental Study on the Development of New Energy Performance Index in Office Buildings

Recently, there have been significant concerns regarding excessive energy use in office buildings with a large window-to-wall ratio (WWR) because of the curtain wall structure. However, prior research has confirmed that the impact of the window area on energy consumption varies depending on building size. A newly proposed window-to-floor ratio (WFR) correlates better with energy consumption in the building. In this paper, we derived the correlation by analyzing a simulation using EnergyPlus, and the results are as follows. In the case of small buildings, the results of this study showed that the WWR and energy requirement increase proportionally, and the smaller the size is, the higher the energy sensitivity will be. However, results also confirmed that this correlation was not established for buildings approximately 3600 m2 or larger. Nevertheless, from analyzing the correlation between the WFR and the energy requirements, it could be deduced that energy required increased proportionally when the WFR was 0.1 or higher. On the other hand, the correlation between WWR, U-value, solar heat gain coefficient (SHGC), and material property values of windows had little effect on energy when the WWR was 20%, and the highest effect was seen at a WWR of 100%. Further, with an SHGC below 0.3, the energy requirement decreased with an increasing WWR, regardless of U-value. In addition, we confirmed the need for in-depth research on the impact of the windows’ U-value, SHGC, and WWR, and this will be verified through future studies. In future studies on window performance, U-value, SHGC, visible light transmittance (VLT), wall U-value as sensitivity variables, and correlation between WFR and building size will be examined.

Influences of sub-atmospheric pressure on downward flame spread over typical insulation material with parallel glass curtain wall structure in underground buildings

Downward flame spread over insulation materials by restriction of parallel glass curtain wall is an important potential scenario in modern underground building fire accidents. Meanwhile, considering the continuous challenge of research efforts in low pressure fire behavior, experimental investigation was conducted for the individual and coupling effects of pressure and curtain wall spacing on flexible polyurethane (FPU) downward flame spreading characteristics. Three pressures (70/85/100 kPa) below or near atmospheric pressure, and six kinds of spacings (4.5/6.0/8.5/11.0/14.0 cm and non-curtain wall) were applied to give a phenomenological study on the complicated variations of pyrolysis front, melting and dripping process, burning rate, flame spread velocity, flame height and pulsation frequency. First, evolution of vertex angle in pyrolysis front was observed to be stable and insensitive to both ambient pressure and interlayer spacing. Also, three dripping formations of molten fuel were found, and enhanced by decreasing pressure and spacing. Second, comprehensive understandings of coupling effects on burning rate, spread velocity and various heat transfer components were performed and formulated with semi-quantitative correlations theoretically. Finally, nonmonotonic tendencies of spacing vs. flame height or pulsation frequency were interpreted based on classical fluid and fire dynamic theory. This work could be valuable for fire hazardous analysis of modern building under sub-atmospheric environment.

Safety Evaluation of Dry-fasten Stone Curtain Wall Structure of Existing Building

Stone curtain walls are more and more widely used due to their good decorative effect and hard texture. However, with the increase of their service life, many safety issues have gradually appeared and caused widespread concern from all walks of life. The dry-fasten stone curtain wall of an office building has been used for more than 12 years. Through on-site inspection and testing of the verticality of the stone curtain wall, the connection node between the stone curtain wall and the main structure, the stone curtain wall framework system, the curtain wall stone panel and weather resisting silicone sealant, some suggestions for transformation are proposed for the existed problems.

On the Function and Exertion of Management in Architectural Curtain Wall Design

<p>Curtain wall structure is the common type of external fixation structure of high-rise and super-high-rise buildings. The application advantages of curtain wall structure have been paid attention to by engineers, so its application is more and more extensive. Based on this, this paper briefly expounds the basic concept of curtain wall, and puts forward the development strategy of management work in building curtain wall construction, aiming at deeply analyzing the current situation of building curtain wall construction in China and deeply exploring the role of management work in building curtain wall construction stage from the project management level.</p>

Classification of Curtain Walls: Analysis of Classification Features

The work is devoted to the development of classification of curtain wall structures as a necessary condition for the formation of a system regulatory framework for the design, manufacture and installation of translucent structures. The analysis conducted shows that at present the domestic system of regulating translucent structures is not sufficiently developed and structured. A wide use of borrowed foreign words and slang terms is noted among the specialists. In the basic normative documents concerning the design, construction and operation of buildings in general, and in specialized documents (on fire safety, energy efficiency, etc.) to refer to translucent structures terms and definitions that are often not consistent with each other are used. Until recently, a standardized classification of curtain walls has not been developed, appropriate standardized terms have not been defined, effective and recommended applications of facades of various types have not been formulated. The article analyzes some existing translucent facades classifications. The basis of the classification was the allocation of the main classification feature - the structural type of the frame. It is assumed that this classification feature is decisive, and on its basis should be formed a modern regulatory framework in the field of translucent facades. Other classification features that are necessary for a more detailed classification of structures are considered.

Deep Space, Thin Walls: Environmental and Material Precursors to the Postwar Skyscraper

The glass skyscraper was a dream of architects and historians alike throughout the early and mid-twentieth century, but the ubiquity of the “glass box” occurred decades after Ludwig Mies van der Rohe's seminal proposals in 1922. In fact, these and other proposals for all-glass building skins were ridiculed by the profession, in particular Chicago architect George C. Nimmons, designer of the first “windowless department store” for Sears, Roebuck in 1934. Heating and cooling costs, he argued, would be prohibitive in such a building, and scientific writers sided with him; with modern services, noted Architectural Forum, the window “dies hard.” As Thomas Leslie, Saranya Panchaseelan, Shawn Barron, and Paolo Orlando describe in Deep Space, Thin Walls: Environmental and Material Precursors to the Postwar Skyscraper, despite the critics, enthusiasm for new technologies—fluorescent lighting and air-conditioning in particular—influenced a generation of solid curtain wall structures, including Pittsburgh's Alcoa Building and Chicago's Prudential Building. Improvements in glazing lagged behind the development of air-conditioning and lighting, however, and problems with the performance of glass challenged these structures’ solidity. Insulated window units and heat-absorbing glass emerged in the late 1940s and early 1950s, providing technical answers to the formula suggested by interior services, and the resulting glass skins emerged—some thirty years after Mies's experiments—as economically logical responses to the changed material possibilities.

대규모 개방형 사무실의 분할공간에 대한 조광제어 시스템의 적용

This study investigates system performances of a daylight dimming control installed in a large open-plan office space with a curtain wall structure. Under a variety of daylight conditions, computer simulations were performed for two zones of the office space which are facing east and west. Results indicate that the changes of photosensor illuminances were strongly influenced by the direct component of daylight under clear and intermediate sky. Overcast sky was a weak contributor to the changes due to diffused components of daylight. For the majority of time periods under all sky conditions, the dimming control system overshot a target illuminance of 750 lx due to insufficient dimmed levels. Reasonable lighting energy savings were achieved under clear and intermediate sky conditions. Overcast sky was not a favorable condition for lighting energy savings due to insufficient daylight. Strong linear correlations existed between desktop and photosensor illuminances by daylight under all sky conditions. Statistical test results imply that reasonable reductions of error variance can be achieved for the correlations.

커튼월 구조의 사무실 공간에서 조광제어 시스템의 최적 제어효과 예측

This study examines the control performance of a photoelectric dimming control system applied to an office space with a curtain wall structure. The space was divided into 9 zones for lighting controls. Two zone facing north (zone 2) and south (zone 8) were used for analyses using computer simulations under a variety of daylight conditions. Results indicate that the dimming control system failed to provide necessary target illuminance under all blind conditions in zone 2 due to excessive dimming from lighting fixtures. In zone 8, the control system overshot the target illuminance for the majority of daylight conditions. Noblind condition in March was the best condition to keep optimum dimming levels with lighting energy savings of 78.2%. Energy savings in zone 8 ranged from 28.7% to 78.2%. Strong correlation existed between the desktop and photosensor illuminance levels by daylight. The correlation did not always show particular patterns according to the direction of window.

A linearized approach for the seismic response analysis of flexible cable net structures

Cable net structures are characterized by significant geometrical nonlinear properties. The linear modal superposition method (LMSM), which ignores the effect of nonlinearity, is believed not suitable for the seismic response analysis of this kind of structures. To conquer the drawback of LMSM, a non-iterative linearization method (NILM) is proposed in this paper. An energy parameter named the “stiffness parameter” is utilized in generating the nonlinear equivalent single degree of freedom (ESDF) systems for the dominant vibration modes of cable nets. The nonlinear stiffness of an ESDF system is simulated by a quadratic function about the equivalent displacement. Based on a stochastic linearization process, the relationship between the equivalent linear stiffness and the displacement response of a modal ESDF system is established. Then the structural responses are computed according to the design response spectra through a non-iterative procedure. Finally, the effectiveness of the proposed NILM is illustrated by a numerical example that carried out on a trapezoid-shaped cable net supported curtain wall structure. It is demonstrated that the proposed NILM, which takes the stiffness hardening effect into consideration, could not only yield better results than the LMSM does, but also exhibit satisfying timesaving property over the nonlinear RHA.

Sound Transmission between Rooms with Curtain Wall Façades: A Case Study

Curtain walls have reached good performances in terms of façade sound and thermal insulation, as well as solar protection. Nevertheless, the sound insulation performance of the partition between adjoining rooms with continuous curtain wall façades is often reduced by the presence of direct and flanking transmission through the junction with the façade itself. In this work, flanking and direct structural transmissions are analysed with reference to the joints of the mullion of the curtain wall with lightweight plasterboard partitions. Airborne sound insulation and vibration measurements were made in two adjacent rooms affected by the acoustic problems determined by the curtain wall joint. Traditional acoustic measurements, carried out according to EN ISO 16283–1, highlighted problems in sound insulation between rooms, but without any indication on different sound transmission paths through the wall. Vibration measurements were made for every part of the system (frame columns and beams, window panes, plasterboard wall, plasterboard false ceiling, etc.) to better understand the sound transmission paths in these kinds of structures. In this paper the results of this analysis are presented. Moreover, taking into account previous works and measurements made in this research field, different solutions for curtain wall structures are analysed and technical suggestions are given to improve airborne sound insulation between rooms separated by partitions mounted up to metal frames.

Analysis of Direct and Flanking Sound Transmission Between Rooms with Curtain Wall Facades

Curtain walls have nowadays reached good performance in terms of façade sound insulation, thermal insulation and solar protection.In this work, flanking and direct structural transmission are analysed with reference to the joints of the mullion of the curtain wall with lightweight plasterboard partitions. Airborne sound insulation and vibrational measurements were made in two adjacent rooms affected by the acoustic problems determined by the curtain wall joint.Traditional acoustic measurements carried out according to EN ISO 16283-1 highlight problems in sound insulation between rooms, but without any indication on different sound transmission paths through the wall. Vibrational measurements were made for every part of the system (frame columns and beams, windows’ glasses, plasterboard wall, plasterboard false ceiling, etc.) to better understand the sound transmission paths in these kinds of structures.Taking into account previous works and measurements made in this research field, different solutions for curtain wall structures are analysed and technical suggestions are given to improve airborne sound insulation between rooms separated by partitions mounted up to metal frames.

Damage evaluation of single-layer cable net façade

Damage such as cable pre-stress loss and anchorage failure may occur in a glass curtain wall structure supported by single-layer plane cable net but the influence on overall structural responses has not yet been identified. A finite-element model considering the stiffness contribution from glass panels is established to study the effects of two forms of damage: pre-stress loss and anchorage failure. The accuracy and reliability of the numerical model are validated experimentally, and the effects of stiffness of the glass panel on stress distributions are discussed. Compared to experimental results, the finite-element model has sufficient accuracy to quantify the damage effects. The contribution from bending stiffness of glass panels to overall structural stiffness is identified as about 10·6% and that from the glass panel membrane effect is about 12·2%. The modelling approach is extended to describe a realistic 15 m × 15 m glass curtain wall structure. The corresponding parametric analysis demonstrates that the stiffness contribution from glass panels depends on certain design parameters (e.g. number of glass grids and overall span), but can be ignored for structures with more than ten grids. In the investigated structures with 6∼15 grids, almost no difference was found between the effects of damage on the glass curtain wall structure and on the pure supporting cable net structure.

SGP的力学性能研究综述

聚乙烯醇缩丁醛中间膜(PVB)在过去几十年被广泛应用于夹层玻璃中。如今新型的离子性中间膜(SGP)较之PVB具有更好的强度和刚度，SGP的采用使得夹层玻璃从之前的仅仅作为安全玻璃发展为结构的一部分。基于其良好的力学性能，SGP在幕墙结构中得到越来越广泛的应用，特别是一些超高层和大型城市公共建筑。然而，到目前为止，对SGP的力学性能尚未有系统的研究，这对夹层玻璃的设计造成了一定困难。本文主要介绍了国内外关于SGP力学性能的研究现状，并根据试验目的和方法的不同进行了归纳总结。 Polyvinyl butyral (PVB) has been widely adopted for interlayer in laminated glass in the past dec-ades. Nowadays, a new interlayer SentryGlas®Plus (SGP) has been developed, which has better stiffness and strength compared with PVB. SGP’s application makes laminated glass not only to be shatterproof glass, but to be a part of the structure. Due to its superior mechanical properties, SGP gains more and more application in curtain wall structures, especially in super high-rise buildings and large-scale public buildings. Nevertheless, there is no systematic study on SGP’s mechanical property, which causes some difficulties in the design of laminated glass. This paper reviews the present researches on mechanical performance of the SGP around the world.