Structural insulated panels (SIPs) are a panelized building system composed of external oriented strandboard wood sheets bonded to a lightweight boardstock or pour-in-place foam core. This project investigated the structural behavior of OSB-faced SIPs subject to short-term out-of-plane transverse loading. A total of 35 panels with varying types of foam core, thickness and other construction details were subjected to partially distributed uniform loading. The results showed that the ultimate shear resistance of SIPs is proportional to the mechanical properties of the core, and inversely proportional to the thickness of the core. The observed relationship between core shear stress at failure and core thickness was used to calibrate a reliability-based design expression to predict the shear strength of full-size panels based on properties obtained from small-scale foam material tests. Sandwich panel theory can accurately predict the initial stiffness of SIPs when behavior remains in the linear range. Finally, recommendations regarding panel design and construction were made to improve the shear behavior of SIPs.
The demand for Structural Insulated Panels (SIPs) as an alternative to light frame construction in residential and light-commercial buildings is increasing, driving the the need for proper design requirements to satisfy regulatory agencies and building officials. A combined experimental and analytical study was conducted to investigate the structural behavior of OSB-faced Structural Insulated Panels (SIPs) subject to short-term axial loading. Panels with varying types of foam core, thickness, and other construction details were subjected to concentric and eccentric loading. Reliability-based design expressions were developed for the ultimate limit state of SIPs subjected to short duration concentric and eccentric axial loading. The results were also compared to current allowable stress design practices. In addition to presenting important test data for researchers, this study generated a number of practical manufacturing and design recommendations to improve the performance of SIPs.
Shock tube testing was used to assess the blast performance of a proprietary metal mesh drapery known as “GuardianCoil”. The system was used to stop projectiles from fragmentation of unreinforced masonry (URM) walls and glazed windows and was installed on the unloaded/interior side of these non-structural elements. Each test sample was subjected to a single, destructive pressure-impulse combination generating high velocity projectiles. The GuardianCoil contained the entirety of the unreinforced masonry block walls and prevented potentially life threatening projectiles from penetrating the test area. It also contained the entirety of the large glass fragments within the first meter of the drapery. The pieces of mortar or glass that penetrated the test area were limited to the weave size, and did not pose a life safety hazard.
Preliminary Seismic Risk Screening Tool A preliminary seismic risk screening tool was developed to exempt buildings from detailed seismic risk assessment if key exemption criteria are met. The exemption criteria are based on: a seismic categorization system linked to anticipated building damage and seismicity; whether or not the building was designed using modern seismic design provisions; and the remaining time that the building will be occupied. The tool also provides a second list of criteria, which if satisfied, will automatically trigger further detailed seismic risk assessment.
This study evaluated bond behavior of lap-spliced reinforced concrete beams subjected to high strain rates. Eleven companion pairs of beams, each consisting of two nominally identical specimens, were designed, built and tested. One beam from each companion pair was tested under static loads generating an average strain rate of 10-5 s-1 , while the other was subjected to high strain rates in the range of 1.0 s-1 generated using a shock tube. Average peak dynamic beam resistance increased by 30% relative to the reference static conditions due to high strain rate effects. Part of this increase was attributed to improvements in the load carrying capacity of the lap splices, which on average experienced a dynamic increase factor (DIF) applied to bond strength of 1.28. Regardless of strain rate, it was found that the bond strength of splices with and without transverse reinforcement increased in proportion to the ratios of the minimum cover depth and the splice length to bar diameter, respectively.
RCBlast was developed to conduct dynamic inelastic response history analysis of structural elements subjected to blast-induced shock waves. It can be used to quickly generate SDOF time histories and PI diagrams for user defined blast threats. The software has a built-in structural analysis module that can generate high fidelity resistance curves for common one-way reinforced concrete elements incorporating: advanced material models; externally bonded FRP retrofits; variable axial load; compression membrane arching action; non-linear behavior; and more. Free download from http://www.rcblast.ca/
OverPressure abbreviated is an easy-to-use software tool designed to compute the blast effects caused by the surface detonation of high explosive using UFC 03-0340-02 (2008) blast parameter data. The tool can generate incident and reflected pressure time-histories suitable for use in single-degree-of-freedom (SDOF) analysis. The pressure-time histories generated by can be imported directly into RCBlast (2013) for inelastic dynamic analysis of blast-loaded structures. The software can also be used to back-calculate TNT charge-weight and stand-off distance, given a specific pressure-impulse combination. OverPressure is available as a free download.