Journal of Computing in Civil Engineering, Jul 1, 2017
AbstractDuring the past decade, building information modeling (BIM) has significantly influenced ... more AbstractDuring the past decade, building information modeling (BIM) has significantly influenced the construction industry. However, none of the available BIM tools and frameworks focuses on modula...
Energy simulation tools can provide information on the amount of heat transfer through building e... more Energy simulation tools can provide information on the amount of heat transfer through building envelope components, which are considered the main sources of heat loss in buildings. Therefore, it is important to improve the quality of outputs from energy simulation tools and also the process of obtaining them. In this paper, a new Building Energy Performance Assessment Tool (BEPAT) is introduced, which provides users with granular data related to heat transfer through every single wall, window, door, roof, and floor in a building and automatically saves all the related data in text files. This information can be used to identify the envelope components for thermal improvement through energy retrofit or during the design phase. The generated data can also be adopted in the design of energy smart homes, building design tools, and energy retrofit tools as a supplementary dataset. BEPAT is developed by modifying EnergyPlus source code as the energy simulation engine using C++, which only requires Input Data File (IDF) and weather file to perform the energy simulation and automatically provide detailed output. To validate the BEPAT results, a computer model is developed in Revit for use in BEPAT. Validating BEPAT's output with EnergyPlus "advanced output" shows a difference of less than 2% and thus establishing the capability of this tool to facilitate the provision of detailed output on the quantity of heat transfer through walls, fenestrations, roofs, and floors.
ABSTRACT This research is mainly focused on the experimental measurement of R-value by several di... more ABSTRACT This research is mainly focused on the experimental measurement of R-value by several different models. Building energy consumption accounts for about 40% of the total energy use in the U.S, and therefore accurate energy simulation is desired. The R-value is one of the key parameters that can influence the energy simulation results and therefore is of great importance. The Average Model has long been the most widely accepted method to measure the thermal properties of building components. However, its steady-state assumption and dependence on temperature difference limit its use especially for in-situ measurement. In this study, several dynamic models, including the Pentaur Model and R-C Network Models, are studied with test data obtained from a series of hot box tests performed in the Building Enclosure Testing Laboratory. The results show that the 3R2C model has the best performance and a desirable stability of accuracy with respect to different levels of temperature difference, and therefore is recommended for practical measurement. The results also indicate that unlike the Average Model, the accuracy of dynamic models does not necessarily depend on the level of temperature difference.
WIT Transactions on the Built Environment, Aug 29, 2001
Racking motions during an earthquake can lead to serviceability failure (e.g., glazing gasket pul... more Racking motions during an earthquake can lead to serviceability failure (e.g., glazing gasket pullout. sealant damage. glass edge damage and glass cracking) or even ultimate failure (in the form of glass fallout that presents a threat to life safety) in conventionally glazed wall systemseven those that meet current building code provisions for nonstructural elements. A new approach to mitigation of seismic risk in conventionally glazed wall systems with architectural glass panels has been developed a t the Building Envelope Research Laboratory (BERL) at The Pennsylvania State University. The essence of the approach is t o modify the rectangular geometry of architectural glass panels at the corners through rounding. A pilot study at BERL has shown that rounding the corners of architectural glass panels can increase the drift capacity of the panels significantly and that maximum effectiveness is achieved by employing rounded corners with a 1 in. radius of curvature along with beveled and polished glass edges. Results of these inplane dynamic racking tests performed on full-scale mock-ups of curtain wall sections glazed with architectural glass panels of different glass types. employing various radii of curvature a t the corners, various glass edge conditions. and varying glass-to-frame clearances are presented.
Abstract: This chapter reviews lessons learned from the seismic response of glass in windows, sto... more Abstract: This chapter reviews lessons learned from the seismic response of glass in windows, storefronts, and curtain walls in actual earthquakes, as well as in laboratory experimental studies involving in-plane cyclic racking tests. New developments in analytical methods to predict the response of architectural glass in earthquakes (e.g. drift that causes glass cracking) are discussed. The authors also discuss methods to mitigate architectural glass damage during earthquakes, including the use of sufficient glass-to-frame clearance, fully tempered and/or laminated glass, structural silicone glazing (SSG), adhered and anchored safety films, and rounded corner glass.
A research project was undertaken recently at Penn State University to study the simulated seismi... more A research project was undertaken recently at Penn State University to study the simulated seismic performance of “Structural Sealant Glazing” (SSG) used to adhere glass panels to common curtain wall framing systems. In the most common type of SSG curtain wall construction, referred to as “two-side” SSG, two glass panel edges (typically opposing vertical edges) are adhered to the support framing using structural sealant, while the other glass panel edges are mechanically fastened to the support framing. In this study, full-scale two-side SSG curtain wall mock-ups consisting of three, side-byside glass panels were subjected to cyclic racking displacements to characterize their performance and to identify sealant and glass component failure modes under serviceability and ultimate racking displacement conditions. Attempts were also made to develop kinematic-based models to predict failure states (e.g., structural sealant failure) of the SSG curtain walls. This paper discusses the details of the predictive model and its evaluation on the basis of comparisons with mock-up test data. The model developed appears to give good estimates of the observed sealant failure drift. Conclusions and recommendations regarding appropriateness and limitations of the predictive model are provided.
... Richard A. Behr, Paul A. Kremer, Ali M. Memari. ... The primary aspects of the invention are ... more ... Richard A. Behr, Paul A. Kremer, Ali M. Memari. ... The primary aspects of the invention are the removal of material at glass panel corners (eg, by rounding the glass corners) and subsequent finishing of the glass edges in the modified corner regions to minimize protrusions and ...
Abstract Understanding damage mechanisms and associated facility challenges for curtain wall syst... more Abstract Understanding damage mechanisms and associated facility challenges for curtain wall systems with different boundary conditions is critical in their performance evaluation and selection during the design stage of a building's lifecycle, in particular if vulnerable to earthquake effects. While many different styles and configurations exist, limited research has been conducted on unitized four-sided structural sealant glazing (4SSG) with re-entrant corners under dynamic racking testing conditions. As such, this paper details a study on full-scale unitized 4SSG curtain wall system mockups featuring a re-entrant corner and subjected to cyclic racking displacements. Racking tests were carried out in accordance with the American Architectural Manufacturers Association (AAMA) 501.6 protocol. Glass fallout, sealant adhesive or cohesive failure, and glass cracking failure modes were identified as limit states and corresponding drift levels were determined. Results of these tests on full-scale specimens are presented here and some of the challenges in data collection and accuracy when using a racking facility are discussed.
Results of cyclic racking tests on EN-WALL 7250 unitized curtain wall system mockups are presente... more Results of cyclic racking tests on EN-WALL 7250 unitized curtain wall system mockups are presented. Mockups had overall dimensions of 180 in. wide by 156 in. high and were comprised of nine glass panels adhered to aluminum framing with 3M™ VHB™ structural glazing tape structural seals and structural sealant weatherseals. Racking tests followed the AAMA 501.6 protocol to characterize the performance of the system. Tests were carried out in a step-wise manner in order to stop the test after each drift increment to inspect the mockup for any damage. A complete description of the unitized system design is presented along with test observations
Structural Engineering and Mechanics, Mar 10, 2007
... e q ( minimum principal strain ), -345.7, -217, -202.7, -224. ( angle between maximum princip... more ... e q ( minimum principal strain ), -345.7, -217, -202.7, -224. ( angle between maximum principal strain and rosette reference grid), 25.4, 40.1, 21.1, 38.5. Figure 1. General glazing details forcurtain wall mock-up tested. Figure 2. Dynamic Racking Test Facility schematic. ...
Driven by desire to reduce carbon footprint in building construction that in modern times has rel... more Driven by desire to reduce carbon footprint in building construction that in modern times has relied heavily on masonry and concrete whose production is associated with burning excessive amounts of fuel, use of wood offers the ideal alternative. Cross-Laminated Timber (CLT) is an esthetically pleasing, mass-timber panelized product that offers users a cost-effective, renewable, durable, fire-resistant alternative to traditional building materials, such as masonry, concrete, and light-framing. A significant benefit to developers and community stockholders in the USA is that the raw materials required to produce CLT can be obtained domestically in timber rich rural areas, helping job growth in those areas, shortening supply chains, and reducing reliance on imported materials. The prefabrication process used to fabricate CLT panels provide users of the construction materials access to all the advantages offered by off-site construction methods such as factory quality control, just-in-time delivery, and accelerated construction. In this chapter, the original light-framing system of a traditional style single-family residential dwelling is converted to a panelized CLT structural support system. The chapter provides the basis of design, typical design process, and explains the challenges associated with using the alternative framing system.
The performance of glazing systems in past (mostly US) earthquakes is reviewed. The mechanism of ... more The performance of glazing systems in past (mostly US) earthquakes is reviewed. The mechanism of glass failure in curtain walls and possible sources of seismic failure of glass is explained. In general, past earthquakes have revealed that glass held in punched window frames, storefronts, and curtain walls are vulnerable. Some approaches to reduce glass damage in earthquakes are also discussed. Such methods include the use of large glass-to-frame clearance, the use of safety film, and the use of structural silicone glazing. Recent research on innovative ways to mitigate seismic damage to architectural glass is also reviewed. Finally, current trends in curtain wall construction for improved seismic performance of architectural glass are discussed.
Journal of Computing in Civil Engineering, Jul 1, 2017
AbstractDuring the past decade, building information modeling (BIM) has significantly influenced ... more AbstractDuring the past decade, building information modeling (BIM) has significantly influenced the construction industry. However, none of the available BIM tools and frameworks focuses on modula...
Energy simulation tools can provide information on the amount of heat transfer through building e... more Energy simulation tools can provide information on the amount of heat transfer through building envelope components, which are considered the main sources of heat loss in buildings. Therefore, it is important to improve the quality of outputs from energy simulation tools and also the process of obtaining them. In this paper, a new Building Energy Performance Assessment Tool (BEPAT) is introduced, which provides users with granular data related to heat transfer through every single wall, window, door, roof, and floor in a building and automatically saves all the related data in text files. This information can be used to identify the envelope components for thermal improvement through energy retrofit or during the design phase. The generated data can also be adopted in the design of energy smart homes, building design tools, and energy retrofit tools as a supplementary dataset. BEPAT is developed by modifying EnergyPlus source code as the energy simulation engine using C++, which only requires Input Data File (IDF) and weather file to perform the energy simulation and automatically provide detailed output. To validate the BEPAT results, a computer model is developed in Revit for use in BEPAT. Validating BEPAT's output with EnergyPlus "advanced output" shows a difference of less than 2% and thus establishing the capability of this tool to facilitate the provision of detailed output on the quantity of heat transfer through walls, fenestrations, roofs, and floors.
ABSTRACT This research is mainly focused on the experimental measurement of R-value by several di... more ABSTRACT This research is mainly focused on the experimental measurement of R-value by several different models. Building energy consumption accounts for about 40% of the total energy use in the U.S, and therefore accurate energy simulation is desired. The R-value is one of the key parameters that can influence the energy simulation results and therefore is of great importance. The Average Model has long been the most widely accepted method to measure the thermal properties of building components. However, its steady-state assumption and dependence on temperature difference limit its use especially for in-situ measurement. In this study, several dynamic models, including the Pentaur Model and R-C Network Models, are studied with test data obtained from a series of hot box tests performed in the Building Enclosure Testing Laboratory. The results show that the 3R2C model has the best performance and a desirable stability of accuracy with respect to different levels of temperature difference, and therefore is recommended for practical measurement. The results also indicate that unlike the Average Model, the accuracy of dynamic models does not necessarily depend on the level of temperature difference.
WIT Transactions on the Built Environment, Aug 29, 2001
Racking motions during an earthquake can lead to serviceability failure (e.g., glazing gasket pul... more Racking motions during an earthquake can lead to serviceability failure (e.g., glazing gasket pullout. sealant damage. glass edge damage and glass cracking) or even ultimate failure (in the form of glass fallout that presents a threat to life safety) in conventionally glazed wall systemseven those that meet current building code provisions for nonstructural elements. A new approach to mitigation of seismic risk in conventionally glazed wall systems with architectural glass panels has been developed a t the Building Envelope Research Laboratory (BERL) at The Pennsylvania State University. The essence of the approach is t o modify the rectangular geometry of architectural glass panels at the corners through rounding. A pilot study at BERL has shown that rounding the corners of architectural glass panels can increase the drift capacity of the panels significantly and that maximum effectiveness is achieved by employing rounded corners with a 1 in. radius of curvature along with beveled and polished glass edges. Results of these inplane dynamic racking tests performed on full-scale mock-ups of curtain wall sections glazed with architectural glass panels of different glass types. employing various radii of curvature a t the corners, various glass edge conditions. and varying glass-to-frame clearances are presented.
Abstract: This chapter reviews lessons learned from the seismic response of glass in windows, sto... more Abstract: This chapter reviews lessons learned from the seismic response of glass in windows, storefronts, and curtain walls in actual earthquakes, as well as in laboratory experimental studies involving in-plane cyclic racking tests. New developments in analytical methods to predict the response of architectural glass in earthquakes (e.g. drift that causes glass cracking) are discussed. The authors also discuss methods to mitigate architectural glass damage during earthquakes, including the use of sufficient glass-to-frame clearance, fully tempered and/or laminated glass, structural silicone glazing (SSG), adhered and anchored safety films, and rounded corner glass.
A research project was undertaken recently at Penn State University to study the simulated seismi... more A research project was undertaken recently at Penn State University to study the simulated seismic performance of “Structural Sealant Glazing” (SSG) used to adhere glass panels to common curtain wall framing systems. In the most common type of SSG curtain wall construction, referred to as “two-side” SSG, two glass panel edges (typically opposing vertical edges) are adhered to the support framing using structural sealant, while the other glass panel edges are mechanically fastened to the support framing. In this study, full-scale two-side SSG curtain wall mock-ups consisting of three, side-byside glass panels were subjected to cyclic racking displacements to characterize their performance and to identify sealant and glass component failure modes under serviceability and ultimate racking displacement conditions. Attempts were also made to develop kinematic-based models to predict failure states (e.g., structural sealant failure) of the SSG curtain walls. This paper discusses the details of the predictive model and its evaluation on the basis of comparisons with mock-up test data. The model developed appears to give good estimates of the observed sealant failure drift. Conclusions and recommendations regarding appropriateness and limitations of the predictive model are provided.
... Richard A. Behr, Paul A. Kremer, Ali M. Memari. ... The primary aspects of the invention are ... more ... Richard A. Behr, Paul A. Kremer, Ali M. Memari. ... The primary aspects of the invention are the removal of material at glass panel corners (eg, by rounding the glass corners) and subsequent finishing of the glass edges in the modified corner regions to minimize protrusions and ...
Abstract Understanding damage mechanisms and associated facility challenges for curtain wall syst... more Abstract Understanding damage mechanisms and associated facility challenges for curtain wall systems with different boundary conditions is critical in their performance evaluation and selection during the design stage of a building's lifecycle, in particular if vulnerable to earthquake effects. While many different styles and configurations exist, limited research has been conducted on unitized four-sided structural sealant glazing (4SSG) with re-entrant corners under dynamic racking testing conditions. As such, this paper details a study on full-scale unitized 4SSG curtain wall system mockups featuring a re-entrant corner and subjected to cyclic racking displacements. Racking tests were carried out in accordance with the American Architectural Manufacturers Association (AAMA) 501.6 protocol. Glass fallout, sealant adhesive or cohesive failure, and glass cracking failure modes were identified as limit states and corresponding drift levels were determined. Results of these tests on full-scale specimens are presented here and some of the challenges in data collection and accuracy when using a racking facility are discussed.
Results of cyclic racking tests on EN-WALL 7250 unitized curtain wall system mockups are presente... more Results of cyclic racking tests on EN-WALL 7250 unitized curtain wall system mockups are presented. Mockups had overall dimensions of 180 in. wide by 156 in. high and were comprised of nine glass panels adhered to aluminum framing with 3M™ VHB™ structural glazing tape structural seals and structural sealant weatherseals. Racking tests followed the AAMA 501.6 protocol to characterize the performance of the system. Tests were carried out in a step-wise manner in order to stop the test after each drift increment to inspect the mockup for any damage. A complete description of the unitized system design is presented along with test observations
Structural Engineering and Mechanics, Mar 10, 2007
... e q ( minimum principal strain ), -345.7, -217, -202.7, -224. ( angle between maximum princip... more ... e q ( minimum principal strain ), -345.7, -217, -202.7, -224. ( angle between maximum principal strain and rosette reference grid), 25.4, 40.1, 21.1, 38.5. Figure 1. General glazing details forcurtain wall mock-up tested. Figure 2. Dynamic Racking Test Facility schematic. ...
Driven by desire to reduce carbon footprint in building construction that in modern times has rel... more Driven by desire to reduce carbon footprint in building construction that in modern times has relied heavily on masonry and concrete whose production is associated with burning excessive amounts of fuel, use of wood offers the ideal alternative. Cross-Laminated Timber (CLT) is an esthetically pleasing, mass-timber panelized product that offers users a cost-effective, renewable, durable, fire-resistant alternative to traditional building materials, such as masonry, concrete, and light-framing. A significant benefit to developers and community stockholders in the USA is that the raw materials required to produce CLT can be obtained domestically in timber rich rural areas, helping job growth in those areas, shortening supply chains, and reducing reliance on imported materials. The prefabrication process used to fabricate CLT panels provide users of the construction materials access to all the advantages offered by off-site construction methods such as factory quality control, just-in-time delivery, and accelerated construction. In this chapter, the original light-framing system of a traditional style single-family residential dwelling is converted to a panelized CLT structural support system. The chapter provides the basis of design, typical design process, and explains the challenges associated with using the alternative framing system.
The performance of glazing systems in past (mostly US) earthquakes is reviewed. The mechanism of ... more The performance of glazing systems in past (mostly US) earthquakes is reviewed. The mechanism of glass failure in curtain walls and possible sources of seismic failure of glass is explained. In general, past earthquakes have revealed that glass held in punched window frames, storefronts, and curtain walls are vulnerable. Some approaches to reduce glass damage in earthquakes are also discussed. Such methods include the use of large glass-to-frame clearance, the use of safety film, and the use of structural silicone glazing. Recent research on innovative ways to mitigate seismic damage to architectural glass is also reviewed. Finally, current trends in curtain wall construction for improved seismic performance of architectural glass are discussed.
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