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Structural insulated panel (SIP) wall systems have been used in residential and light commercial buildings for the past 60 years. Lack of sufficient published research results on racking load performance and understanding of the influence of fastener types on seismic response has been a deterrent in the widespread use of the wall system in seismically active areas. This paper summarizes the results of a full-scale racking load testing study in which a total of 17 2.4×2.4-m (8×8-ft) SIP wall panels were tested under monotonic and cyclic loading. Four 114-mm (4.5-in.) thick SIP specimens were tested under monotonic loading, while 13 114-mm (4.5-in.) thick SIP specimens were tested under the Consortium of Universities for Research in Earthquake Engineering loading protocol. Parameters such as fastener type, spline design, hold-down anchor location, and sheathing bearing were adjusted throughout the testing to determine their effects on the SIP’s performance. Performance parameters such as peak load a...

A research project was undertaken at Pennsylvania (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-sided 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-sided SSG curtain wall mock-ups consisting of three, side-by-side 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. In addition to testing, kinematic-based models were developed to predict failure states (e.g., structural sealant failure) of the SSG curtain walls. This paper discusses the details of the pred...

This paper summarizes the findings of an experimental study to characterize the cyclic racking and monotonic loading performance of wood-stud and steel-stud wall specimens, which were sheathed on both faces with gypsum wall board (GWB). Some specimens were finished with joint compound at the GWB joints and over screw heads. The study provided data on monotonic and cyclic hysteresis load-displacement relationships. Based on the visual inspection of the specimens during the tests, several aspects of the failure modes were noted. Shear-load capacity and drift capacities were determined based on the envelope curves of the hysteresis cycles. A comparison of the envelope curves for steel-stud and wood-stud specimens provided insight as to the relative behaviors of the two wall system types, including capacity, measures of ductility, and energy dissipation. Finally, the study provided better understanding of the effects of finishing GWB joints on the shear capacity of the wall systems.

A series of 11 tests of full-scale partition walls were conducted to determine the behavior of nonstructural gypsum wallboard partition walls during lateral deformation as might be expected during a major earthquake. The partition walls were constructed as double-sided, 1/2 in. (13 mm) gypsum wallboard partition walls with wood stud framing. The walls deformed laterally in one of two ways: either as a joint-failure mode with racking of the individual gypsum wallboard panels, or by a pier-rotation mode where all the gypsum wallboard panels in a pier rotated as a unit. In all of the tests, the fasteners failed by pulling through the back of the wallboard panel, cutting of the gypsum, or tearing out through the edge of a wallboard panel. In some tests, the strength of the tape and compound was seen to provide adequate support to cause the walls to roll as a single unit, especially when the spacing of fasteners was large. The maximum load resisted varied from 512 N/m (378 lb/ft) to 1,177 N/m (869 lb/ft) and occurred at drifts between 0.68 and 1.87%. The drift when specific damage thresholds occurred was monitored during testing. Damage initiated with slight cracking of the panels at the wall opening at drifts of 0.25%, followed by increasing damage up to drifts of 2%, and minimal additional damage at drifts above 2%. Damage thresholds for cyclic loading often occurred at lower drifts than comparable specimens under monotonic loading.

Laboratory experiments subjected full-scale autoclaved aerated concrete (AAC) cladding panel specimens to static monotonic loading and incrementally increased displacement amplitudes of cyclic racking movements. The objective of the study was to characterize the seismic performance of cladding panel walls made up of the newly introduced AAC in the U.S. market. The study found that conventional connectors used to attach AAC cladding panels to structural systems have not been designed for in-plane seismic resistance and would need to be redesigned in order to safely satisfy building code’s allowable drift.

Results are presented of a pilot study conducted recently at the Pennsylvania State University Building Envelope Research Laboratory (BERL) to investigate the response of curtain wall mock-ups glazed with 6 mm (1/4 in.) annealed monolithic architectural glass panels fitted with anchored applied film under simulated earthquake conditions. Three common film-to-frame anchoring methods were evaluated: (1) structural silicone adhesive [13 mm (1/2 in.) triangular cross section] application along the entire glass panel perimeter; (2) an aluminum bar extrusion to anchor the film to the frame horizontal along only the top of the glass panel; and (3) two aluminum bar extrusions to anchor the film to the frame verticals along the two vertical edges of the glass panel. Serviceability (glass cracking) and ultimate (glass fallout) limit-state data were collected during in-plane dynamic racking tests. Other performance characteristics, such as cohesive failure of the structural silicone adhesive, loss of film-to-glass adhesion, film tearing, damage to aluminum anchor bars, pullout of the filmed glass unit from the frame glazing pockets, and eventual entire unit fallout, were also recorded. These preliminary tests indicated that anchorage type can demonstrably influence both the serviceability (initial glass cracking) and ultimate (glass fragment fallout and entire unit fallout) limit states of “unweathered” filmed glass panels. In this study, the structural silicone anchor provided the best serviceability limit-state performance of the three anchor methods tested, and the top anchor provided the best entire-unit glass fallout resistance.

In-plane dynamic racking crescendo tests were performed on full-scale curtain wall mock-ups dry glazed with six different insulating glass unit (IGU) configurations and one laminated glass unit configuration. The tests were conducted to determine the serviceability and ultimate limit state behaviors of these configurations tested under simulated earthquake-induced lateral drifts. All IGU configurations tested were manufactured with an annealed monolithic pane and a laminated pane with an argon fill and an anodized aluminum spacer between the panes. Several parameters were varied in the laminated pane of each configuration including glass lite thickness and glass type in the laminated pane (annealed, heat strengthened, and fully tempered), and PVB interlayer thickness for the laminated pane. Properties of the annealed inside pane were not varied. For each configuration, average drift values for the occurrence of glass cracking in each IGU pane, glass fallout from the monolithic pane, and pullout and fallout of the entire glass unit are reported. Relevant damage to the aluminum framing is also reported. Results of these tests can be used to assess the seismic resistance of similarly glazed architectural glass panels in practice and to improve the design of asymmetric IGU configurations for use in seismic regions.

The point fixed glass facade system (PFGFS), also known as a spider glass system, is popular because it is the most transparent facade system available for buildings. The glass facade system is fixed to the support structure at minimal points using bolts and spider arms. Generally, the racking performance of these systems is not considered at the design stage. The facade system will be vulnerable to racking actions mainly during severe earthquakes and wind actions if the system does not have sufficient in-plane drift capacity. A unique real-scale in-plane racking laboratory test on a typical PFGFS was conducted to assess the in-plane racking performance. A maximum drift of 2.1% was measured, which was much larger than initially anticipated because of the rigid-body articulation of the system and higher than typical maximum allowable interstory drift for buildings in regions of lower seismicity. A sophisticated nonlinear finite-element (FE) model was developed and conservatively benchmarked against...

This paper describes an innovative wall system for use in residential and commercial construction projects that is reusable, uses less dimensional lumber, and is faster to assemble and install compared to traditional stud wall systems. The wall system is an engineered wall design composed of components fabricated from 5.08 × 5.08 cm (2 in.) (nominal dimensions) nailing strips and oriented strand board fins located in the midsection of the nailing strip. Components can be connected to one another by hinges allowing the system to be collapsible. Laboratory testing has shown that this wall system has significantly improved racking capabilities compared to the traditional stud wall system both with and without sheathing. Additional research is required, however, to enhance this wall system's structural characteristics in bending and axial loads. An economic analysis showed that material costs are cheaper for this wall and assembly, and installation times are less compared to traditional stud wall construction...