Insulating glass units (IGUs) are widely used in glass curtain wall systems (GCWSs) due to their energy efficiency and daylighting benefits. However, premature failures caused by environmental and mechanical factors remain a major concern. Existing quantitative analysis and finite element (FE) modeling methods are also insufficient to capture the multi-factor degradation of edge-seal watertightness under real service conditions. This study presents a comprehensive approach to evaluate the degradation of a key durability indicator, the moisture-resistance time (Tm), under coupled effects of temperature, humidity, ultraviolet (UV) radiation, and shear strain. A total of 219 lab-fabricated IGU strip specimens were subjected to a 4000-hour artificial accelerated aging (AAA) test to provide first-hand experimental data. Based on these results, a hierarchical aging model (containing two primary parameters and sixteen secondary parameters) was developed using a phenomenological approach combined with a naive Bayes framework, with parameters estimated via the Markov Chain Monte Carlo (MCMC) method. A recursive prediction method incorporating local hourly meteorological data and the principle of UV-dose equivalence was then applied to simulate multi-year degradation under realistic service conditions. Results indicate that moisture-resistance time can decrease by over 60% under severe aging conditions and may decline by approximately 24% over three years in Beijing, with seasonal variations in degradation rate. The predicted service life of qualified IGUs in Beijing is approximately 14.4-17.1 years, providing a quantitative basis for durability assessment, maintenance planning, and performance-based design optimization.

Accurate and efficient evaluation of the load-bearing performance of multi-glazed insulating glass units (IGUs) under uniform loads is essential for wind-resistant design and safety assessment of glass curtain wall systems (GCWS). However, existing empirical data and numerical models are insufficient for reliably capturing the mechanical behavior of these novel thin-shell components, particularly for large-deflection analysis. This paper presented and validated two different finite element (FE) modeling methods, considering geometric nonlinearity, material nonlinearity, and uneven load sharing. Simply Supported (SS) and Center Constrained (CC) boundary conditions were used to build three FE models. Their accuracy, computational efficiency, and applicability were discussed and compared with the BAM method. Based on the superior 2-CC method, the effect of cavity thickness on load sharing ratios (LSRs) of quadruple glazed IGUs (QIGUs) was analyzed. It is found that the LSRs vary with load magnitude, and for the currently used Type A product, designing based solely on the stiffness distribution method adopted by the ASTM E1300 may lead to an underestimation of the LSR for Pane 1 by over 30 %, while overestimating the LSR for Pane 4 by nearly 50 %. Furthermore, a parametric analysis was conducted to determine the LSRs for ten types of market-available QIGUs, as preliminary improvements to the stiffness distribution method. Finally, an optimized calculation formula was presented, providing a basis for conventional QIGU design and a reference for future lightweight optimization analysis of multiglazing components.

Silicone structural glazing (SSG) sealants are crucial sealing materials in modern building curtain walls, whose performance degradation may lead to functional and safety issues, posing significant challenges to building safety maintenance. This study comprehensively investigated the effects of temperature, humidity, stress, and ultraviolet (UV) irradiance on the durability of SSG sealants through multi-gradient matrix aging tests, revealing the influence patterns of these four aging factors on tensile bond strength (TBS). Based on aging test data and degradation patterns, a novel degradation model for TBS aging was established by incorporating all four aging factors as variables, enabling the model to reflect their combined effects on TBS degradation. The unknown parameters in the model were calculated using the Markov chain Monte Carlo (MCMC) algorithm and validated against experimental data. A recursive algorithm was developed to predict TBS degradation under actual service conditions based on the degradation model and environmental records, with verification through outdoor aging tests. This study established a service life prediction methodology that combines the degradation model with environmental data through recursive computation and standard-specified strength limits. The results demonstrate that increasing temperature, humidity, stress, and UV irradiation accelerates TBS changes, with influence intensity ranking as UV irradiation > temperature > humidity > stress. Synergistic effects exist among all four factors, where UV irradiation shows the most significant coupling effect by amplifying other factors’ combined impacts, while UV’s primary influence manifests through such synergies rather than independent action. Among temperature, humidity, and stress combined effects, temperature contributes approximately 50%, temperature–humidity interaction about 35%, with temperature-related terms collectively accounting for 90%. The degradation model calculation results show excellent agreement with experimental data (R2 > 0.9, MAE = 0.019 MPa, RMSE = 0.0245 MPa). The characteristic TBS minimum value considering material discreteness and strength assurance rate serves as a reliable criterion for service life evaluation. The proposed prediction method provides essential theoretical and methodological foundations for ensuring long-term safety and maintenance strategies for glass curtain walls.

Precise and rapid calculation of insulating glass units (IGUs) under climate load is crucial for the determination of the durability, aesthetics, and safety of curtain walls during the early design and subsequent service stages. However, available empirical data and numerical simulations are inadequate in accurately evaluating the temperature field and the temperature-induced mechanical behavior of this energy-saving building material, especially the in-plane thermal shear deformations of Polyisobutylene (PIB) and the out-of-plane deformation of the glass panels. In this paper, three pieces of IGUs were used in heat transfer tests to obtain the temperature and displacement fields. Two finite element (FE) models were built based on sequential thermo-mechanical coupling simulation and the calibration approach of the Ideal Gas Law. The applicability, accuracy, and computational efficiency of the models above were compared. A simplified piecewise-linear model for rapidly calculating the temperature field along the thickness direction was proposed by MATLAB surface fittings. Based on the deformation mechanism, the contribution ratios of two main influencing factors to deformations were defined. Simplified calculation formulas applicable to the in-plane thermal deformation of PIB, and the out-of-plane deformation of glass panel were proposed with the coefficient of determination R2 over 0.99, considering the temperature difference of indoor and outdoor environment, rectangular dimension, and the thicknesses of pane and airspace. In addition, the mutual constraint effects were presented and defined in this paper. The detailed analysis of thermal deformation lays the groundwork for further addressing premature failure issues and optimizing edge bond constructions of IGUs.

Precise and rapid evaluation of the temperature field in tripled-glazed insulating glass units (TIGUs) under intense solar radiation is crucial for the thermal-resistant design of glass curtain wall systems (GCWSs) and assessments of building thermal environments. However, available empirical data, traditional Tsol-air method, and numerical simulations are inadequate in accurately calculating the thermal behavior of this emerging energy-efficient building material, particularly for the complex heating effects of direct and diffuse solar radiation and the thermal convection of cavity gas in multilayer glazing systems. This study presents a comprehensive thermal analysis of TIGUs using a refined thermo-fluid-structure interaction (TFSI) finite element (FE) model that accounts for heat conduction, convection (both external and within cavities), and radiative transfer. The improved model, implemented in ANSYS and incorporating D-O radiation, k-epsilon (RNG) viscous, and energy models, demonstrates superior agreement with experimental results and the WINDOW software (MAPE = 2.45%), which addresses key limitations of existing standards and the Tsol-air method. A parametric study based on meteorological data from ten representative cities was conducted, identifying the influence of outdoor temperature, direct radiation, and diffuse radiation on the TIGU temperature field, with their effects quantitatively characterized by sensitivity coefficients a, b, and C. The concept of "peak region" was introduced to intuitively describe the non-monotonic thermal behavior under strong solar radiation. For the widely used configuration (6+12Air+6+12Air+6 mm), fitted equations were derived using least squares and Lagrange interpolation methods, with R-2 > 0.99, enabling efficient estimation of temperature distributions under long-term climatic conditions.

Polyisobutylene (PIB), commonly used as the primary sealant of double, triple, and multi glazed insulating glass units (IGUs), provides the key moisture barrier function and determines the expected lifespan of the IGUs and even the entire glass curtain wall systems (GCWSs). Slipping and debonding of the PIB, caused by temperature changes, have resulted in numerous instances of premature failure of building envelopes. However, available research is inadequate in accurately evaluating the service environment of IGUs and thermal-deformation behaviors of this energy-saving building material. This paper presented a simplified method for analyzing the thermal environment of IGUs, considering outdoor air temperature, solar radiation, wind speed, and angle to the horizontal. A numerical modeling method was proposed and validated with the heat transfer tests. Three finite element (FE) models were built and utilized for the precise analysis of temperature-induced deformations of double, tripled, and quadruple glazed IGUs. Simplified calculation formulas for the maximum thermal deformation of PIB in the X and Y directions under different temperature conditions were obtained, taking a new concept "cavity-to-pane ratio" into consideration. Finally, the relationship between the PIB's temperatureinduced deformation and its probability was proposed. The results show that the IGUs in Beijing suffer more than 22 % of their time in harsh service conditions where the difference between indoor and outdoor temperatures exceeds 20 degrees C. For DIGUs, the maximum temperature-induced deformations of the PIB in X (along the short side of the panel) and Y (along the long side of the panel) directions are 0.142 and 0.214 mm, respectively, corresponding to shear strains of 28.4 % and 42.8 % for the PIB with a thickness of only 0.5 mm. For TIGUs, the maximum deformations increase to 0.159 and 0.239 mm, corresponding to shear strains of 31.8 % and 47.8 %. For QIGUs and the other multi-glazed IGUs, these values can increase to 36.8 % and 55.4 % or more. The methodology proposed in this paper aims to lay the groundwork for further addressing premature failure issues and optimizing edge bond constructions of multi-glazed IGUs.

Precise and rapid calculation of triple-glazed insulating glass units (TIGUs) under uniform loads is crucial for the wind-resistant design and safety assessments of glass curtain wall systems (GCWS). However, available empirical data and numerical simulations are inadequate in accurately evaluating the mechanical behavior of this material. This paper presented an experimental and numerical study on the load-bearing performance of TIGUs, focusing on the equivalent thickness and load-sharing ratio calculation. Three pieces of TIGUs and five pieces of Polyvinyl Butyral (PVB)-laminated TIGUs were used in the loading tests. The major factors varied in the investigation include rectangular dimensions, glass pane thicknesses, and inner and outer airspace thicknesses. Two finite element (FE) models were built based on different methods. The applicability, accuracy, and computational efficiency of the models above were compared. Based on the conceptual and FE parametric analysis, the combined coefficient formula applicable to the calculation of equivalent thickness of PVB-laminated glass was proposed by surface fitting, and the load sharing ratio with respect to changes in the inner and outer airspace thicknesses was investigated. Finally, a simplified calculation method based on airspace coefficients, considering the effects of outer and inner airspace thicknesses, aspect ratio, and area, was proposed, which has superior applicability for precise and rapid evaluation of both TIGUs and PVB-laminated TIGUs commonly used in practical engineering, as the improvements to the stiffness distribution method adopted by the ASTM E1300.

The wind load values of perforated metal panel and its backing plate of curtain wall, as well as the calculation method of deformation and stress of perforated plate, are not specified in current design codes. Three groups of wind tunnel tests with a total of 11 load cases were performed to obtain the influence law of perforation rate, wind speed, wind direction angle and backing plate spacing on the wind load on perforated veneer, front panel and backing plate. Based on the formula of the standard value of wind load in current code, a method of multiplying multiple adjustment coefficients were proposed to calculate the wind load on the perforated metal plate and its backing plate of the curtain wall, and the values or formulas of the adjustment coefficients were given. The finite element analyses of 144 perforated metal panels were carried out, and the influence law of perforation rate, aspect ratio and load on the deformation and stress of perforated metal plates were revealed. Based on the calculation method of large deflection and stress of non-perforated metal sheet in current code, the adjustment coefficients for calculating the deformation and stress of metal sheet with different perforation rate was proposed.

玻璃结构破坏具有明显的脆性特征,易造成公共安全隐患.项目组开展了玻璃结构基础理论和关键技术的创新性研究.识别了玻璃结构构件、节点的失效形态和力学性能,确定了结构构件破坏和失效后承载性能演变机制,建立了不同劣化条件下玻璃结构构件及节点的劣化本构模型;研发了新型高性能加筋增强玻璃构件、多板件组合玻璃构件、金属植入型节点、摩擦型螺栓节点等玻璃结构防倒塌性能提升技术;提出了玻璃结构体系安全冗余设计方法;基于有限-离散元方法,开发了可准确模拟玻璃结构破坏过程的数值计算工具.依据主要研究成果,编制3部技术标准,可为我国玻璃结构的应用提供技术支撑.

Insulating glass units (IGUs) have been widely used in buildings in recent years due to their superior thermal insulation performance. However, because of the panel reciprocating motion and fatigue deterioration of sealants under long-term wind loads, many IGUs have the problem of early failure of watertight properties in real usage. This study aimed to propose a statistical method for wind-induced deflection of IGU panels during the whole life service period, for further precise analysis of the accumulated fatigue damage at the sealed part of the edge bond. By the estimation of the wind occurrence regularity based on wind pressure return period, the events of each wind speed interval during the whole life were obtained for the IGUs at 50m height in Beijing, which are in good agreement with the measured data. Also, the wind-induced deflection analysis method of IGUs based on the formula of airspace coefficient was proposed and verified as an improvement of the original stiffness distribution method with the average relative error compared to the test being about 3% or less. Combining the two methods above, the deformation of the outer and inner panes under wind loads during 30 years was precisely calculated, and the deflection and stress state at selected locations were obtained finally. The results show that the compression displacement at the secondary sealant under the maximum wind pressure is close to 0.3mm (strain 2.5%), and the IGUs are in tens of thousands of times the low amplitude tensile-compression cycle and several times to dozens of times the relatively high amplitude tensile-compression cycle environment. The approach proposed in this paper provides a basis for subsequent studies on the durability of IGUs and the wind-resistant behaviors of curtain wall structures.

This paper reports a comprehensive numerical investigation into the cross-section behavior and resistances of stainless steel lipped channel columns under axis compression. To obtain the influence of strain hardening index n and nominal yield stress σ0.2 on the design DSM compression resistance for a stainless steel lipped channel cross section, numerical parametric study has been firstly performed. It indicates that the strain hardening exponent n has a strong effect on the DSM strength prediction of stainless steel lipped channel columns, but nominal yield stress σ0.2 has a limited effect on the DSM curve due to it already included in the DSM. A DSM model was proposed that could take into account the strain hardening exponent n and different buckling modes, and a range of numerical parametric study was conducted. Based on the proposed DSM model, a set of DSM equations was proposed for stainless steel lipped channel column. The strength predictions formula is suitable for different types of stainless steel materials, and only the corresponding strain hardening coefficient n needs to be selected according to the stainless steel material. The comparison between the test results and design predictions indicates that the proposed equations are able to capture the nominal axial strength of the stainless steel lipped channel column

Currently, there is no detailed approach for designing cold-formed stainless steel lipped channel columns which fail by an interaction between distortional and global buckling. In this paper, the structural behavior of cold-formed stainless steel lipped channel columns that fail in distortional-global interactive buckling is presented. Finite element (FE) models were developed to simulate the members under axial compression. The results obtained from the finite element analysis (FEA) were compared with the test results in terms of failure modes, strengths and load–deformation curves. After successful verification, a comprehensive numerical investigation was undertaken to provide benchmark data for the assessment the nominal strengths predicted by using the current specifications (based on standards from AISI and AS/NZS) and the design equations proposed by Lecce and Rasmussen. The distortional buckling equation in the AISI code leads to overestimation of predicted resistances, while Lecce and Rasmussen’s formula provides conservative predicted resistances for stainless steel lipped channel columns. The AS/NZS code provides a relatively accurate prediction of the strengths. Finally, a design method for stainless steel lipped channel columns is proposed, which provides considerably more accurate predictions. The proposed Direct strength method (DSM) equation has been proven to accurately predict the ultimate capacities of stainless steel lipped channel columns in compression.

本文结合北京某移动互联网产业园项目幕墙的设计过程,详细介绍了跨层单元式幕墙的受力特点和构件设计过程,分析了不锈钢薄板在幕墙中应用的关键技术细节,对比了幕墙用平移式通风器和旋转鼓式通风器的优缺点.本文介绍的设计方法和技术细节可以为类似项目提供参考.

In order to study the performance change and interactions between the main structure and glass curtain wall under the individual and coupled actions of wind and earthquake loadings, on the basis of a 98 m high frame-core wall structure in highly seismic region, a finite element analysis model was built by adding the glass curtain wall according to the specifications. Three groups of three-dimensional seismic records are selected according to the site conditions, and the wind pressure time-history of different return periods was obtained through a 1∶440 scale wind tunnel model test. Then the effects of individual and coupled actions of wind and earthquake on the behavior of the main structure and glass curtain wall was studied by the nonlinear dynamic analysis. The results show that the influence of the main structure on the glass curtain wall was greater than that of the glass curtain wall on the main structure. Whether under the individual or coupled actions of wind and earthquake, the inter-story deformation of the main structure was larger than the deformation of the glass curtain wall itself. Under the design and super-intensity earthquake loadings, the nonlinear response of the main structure and the failure range of the glass curtain wall increased with the load increase, and the growth of structural deformation was greater than the base shear's growth. Under the action of wind, the glass curtain wall was not damaged, the main structure was in an elastic stage, and the base shear, top displacement and the maximum story drift ratio increased linearly. Compared with the effect of rare earthquake alone, when the rare earthquake was coupled with 1.1 times wind pressure of a 100-year return period, the torsional effect appears in the structure, and the story drift ratio increased from 1.0 to 1.3. The nonlinear response of the main structure and the glass curtain wall is greater than the simple superposition of wind and earthquake alone. The top displacement and the maximum story drift were 121% and 106% of the sum of wind and earthquake alone. Under the rare earthquake, the coupling action of the rare earthquake and wind earthquake, the failure of glass curtain wall is more likely to happen on the side parallel to the main direction of earthquake.

The windblown sand-induced degradation of glass panels influences the serviceability and safety of these panels. In this study, the degradation of glass panels subject to windblown sand with different impact velocities and impact angles was studied based on a sandblasting test simulating a sandstorm. After the glass panels were degraded by windblown sand, the surface morphology of the damaged glass panels was observed using scanning electron microscopy, and three damage modes were found: a cutting mode, smash mode, and plastic deformation mode. The mass loss, visible light transmittance, and effective area ratio values of the glass samples were then measured to evaluate the effects of the windblown sand on the panels. The results indicate that, at high abrasive feed rates, the relative mass loss of the glass samples decreases initially and then remains steady with increases in impact time, whereas it increases first and then decreases with an increase in impact angle such as that for ductile materials. Both visible light transmittance and effective area ratio decrease with increases in the impact time and velocities. There exists a positive linear relationship between the visible light transmittance and effective area ratio.

铝镁锰直立锁边金属屋面广泛应用于各类大跨度建筑中,但是关于其抗风揭性能的理论研究较滞后,也缺乏系统性试验研究.为研究屋面板宽度、厚度、T形码支座间距等因素对其抗风揭性能的影响,对12组24个金属屋面试件进行了抗风揭试验.采用接触单元建立了有限元实体模型,模拟其破坏过程,并给出合理的破坏判定准则.提出简化计算模型,推导了极限风压计算式.研究结果表明:所有试件的破坏均是锁边咬合处的脱开造成的,锁边咬合处初始缝隙缺陷会显著降低直立锁边金属屋面的抗风揭能力;增大T形码长度对极限风压的提升较小,减小屋面板宽度、增大屋面板厚度、减小T形码支座间距以及增设抗风夹均能有效提升直立锁边金属屋面的抗风揭性能,其中增设抗风夹效果最为显著;已有研究中有限元分析结果、极限风压计算式结果与试验结果吻合良好,可验证有限元模型及极限风压计算式正确有效,研究成果可为直立锁边金属屋面抗风揭设计与性能评估提供参考.

近年来,随着我国旅游经济的蓬勃发展,玻璃景观桥建设日益增多,但目前我国还没有明确的关于玻璃景观桥桥面的设计方法.本文从桥面材料、桥面荷载和桥面计算模型等方面,给出了玻璃景观桥桥面设计方法,并提出以下建议:①桥面玻璃应使用钢化夹层玻璃,且应采取有效措施防止玻璃自爆;②钢化夹层玻璃宜优先采用具有更好耐久性、耐热性、抗老化能力和力学性能的SGP胶片;③除了正常情况下的应力和变形验算外,还应从安全角度考虑当一片玻璃破碎不利情况下的应力和变形验算,验算结果相比正常情况可适当放宽;④应制定相应措施对玻璃景观桥的运维安全进行严格把控.

为简化多样化玻璃幕墙明框咬合扣盖的分离力计算方法,根据试验和三维数值模拟对4种不同剖面和材料摩擦系数的咬合扣盖进行了研究.通过二维数值模拟建立了咬合扣盖剖面属性和摩擦系数对分离力影响结果的样本库,采用基于1stOpt软件的LM-UGO算法、SM-UGO算法以及基于Matlab的BP神经网络三种方法,对4种咬合扣盖分离力进行了计算和预测.结果表明:LM-UGO算法和SM-UGO算法对于多参数拟合具有良好的性能,对于各变量包含于样本库之内的工程实例具有良好的预测效果,LM-UGO算法的效率更高;BP神经网络构建速度快,但需要多次重复训练才能找到最合理预测的网络模型,其稳定性较差、泛化能力较差;扩大样本数量,能够提高三种方法对咬合扣盖分离力的预测准确率,各变量处于样本库范围之内的咬合扣盖,三种方法均能满足工程的精度需求.

以目前石材幕墙工程中常用的天然干挂饰面石材为代表,通过试验研究不相同吸水率下的花岗岩、石灰石以及砂岩经过不同的防护处理后,在冻融循环作用下压缩强度以及弯曲强度的变化.试验结果表明进行防护处理可以提升石材的抗冻性能.同时通过开展不同次数的冻融循环试验,对这三类石材的抗冻系数随着冻融循环次数的变化进行对比和分析,绘出了抗冻系数与冻融次数的拟合关系曲线,得到了抗冻系数随冻融循环次数的衰减规律并预测了这三类常用石材冻融破坏的最少冻融次数.