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Experimental tests of cross-laminated timber (CLT)-concrete composite floor panels were conducted. The tests consisted of linear-elastic tests of square CLT-concrete composite panels with a novel shear connector to determine elastic orthotropic plate properties. After the linear-elastic tests, the panels were subjected to a patch load at the center of the panel and tested to failure. To investigate load transfer across longitudinal joints between adjacent panels, nonuniform bending tests were conducted. Results from the experimentally measured orthotropic plate properties showed that the shear connector increased the bending stiffness in the weak direction of the panel compared to prior test results using conventional shear connectors. The tests to failure exhibited larger differences in behavior between the strong and weak orientations of the specimens, with both showing substantial inelastic behavior prior to failure. Numerical finite element models of the patch-load test showed good agreement with experimental results. Analytical formulas using the obtained orthotropic plate properties did not agree with experimental results for the patch-load at linear scales, suggesting the simplified method is currently not suited for CLT-concrete two-way bending. Load-transfer tests found that the reinforced concrete topping is capable of transferring load across the longitudinal joint of two parallel panels to enable two-way bending of composite timber–concrete floors and that the addition of a plywood spline with closely spaced screws enables a higher degree of force transfer. [ABSTRACT FROM AUTHOR]

• A 1:6 laboratory model of an elevated building was tested to collapse under surge and wave loading. • System identification is used to quantify out-of-water and in-water frequencies and damping. • Lidar point clouds were used to quantify damage following hydrodynamic testing. • OpenFOAM and OpenSees coupled simulations captured experimental acceleration responses. • Finite element model updating provides insights on parameters influencing structural response. An experimental program of a 1:6 scale elevated wood frame shear-wall residential building was developed to model the damage progression of buildings subjected to increasing hurricane surge depth and wave conditions until collapse. This paper presents testing and system identification methods used to characterize structural engineering properties of the physical model that accumulated damage during hydrodynamic testing under increasing surge depth and wave heights. Methods used include (a) quasi-static lateral load-deformation testing, (b) out-of-water dynamic structural characterization testing under free vibration, ambient vibration, and forced vibration, conducted on the test specimen prior to hydrodynamic testing, (c) in-water dynamic structural characterization during hydrodynamic testing, (d) quantification of accumulated damage in hydrodynamic testing through observed changes in the laser scan point cloud data of the specimen, and (e) finite element model updating. The accumulated damage in the test specimen is correlated to changes in modal features (frequency, damping, and mode shapes) assessed using two output-only system identification (SID) methods. In addition, finite volume numerical models are used to determine detailed pressure distributions on the test specimen which are coupled with finite element (FE) models that are updated, in a phased manner, to understand the contribution of structural and nonstructural components on the modeled stiffness and strength of the physical model. Lastly, the impact of the damage on the modal features of the physical model of the building and their sensitivity to FE model assumptions are presented. [ABSTRACT FROM AUTHOR]

This paper presents an analytical study evaluating the influence of ground motion duration on structural damage of 3-story, 9-story, and 20-story SAC steel moment resisting frame buildings designed for downtown Seattle, WA, USA, using pre-Northridge codes. Two-dimensional nonlinear finite element models of the buildings are used to estimate the damage induced by the ground motions. A set of 44 ground motions is used to study the combined effect of spectral acceleration and ground motion significant duration on drift and damage measures. In addition, 10 spectrally equivalent short-duration shallow crustal ground motions and long-duration subduction zone records are selected to isolate duration effect and assess its effect on the response. For each ground motion pair, incremental dynamic analyses are performed at at least 20 intensity levels and response measures such as peak interstory drift ratio and energy dissipated are tracked. These response measures are combined into two damage metrics that account for the ductility and energy dissipation. Results indicate that the duration of the ground motion influences, above all, the combined damage measures, although some effect on drift-based response measures is also observed for larger levels of drift. These results indicate that because the current assessment methodologies do not capture the effects of ground motion duration, both performance-based and code-based assessment methodologies should be revised to consider damage measures that are sensitive to duration. Copyright © 2016 John Wiley & Sons, Ltd [ABSTRACT FROM AUTHOR]

The use of empirically calibrated moment-rotation models that account for strength and stiffness deterioration of steel frame members is paramount in evaluating the performance of steel structures prone to collapse under seismic loading. These deterioration models are typically used as zero-length springs in a concentrated plasticity formulation; however, a calibration procedure is required when they are used to represent the moment-curvature behavior in distributed plasticity formulations because the resulting moment-rotation response depends on the element integration method. A plastic hinge integration method for using deterioration models in force-based elements is developed and validated using flexural stiffness modifications parameters to recover the exact solution for linear problems while ensuring objective softening response. To guarantee accurate results in both the linear and nonlinear range of response, the flexural stiffness modification parameters are computed at the beginning of the analysis as a function of the user-specified plastic hinge length. With this approach, moment-rotation models that account for strength and stiffness deterioration can be applied in conjunction with force-based plastic hinge beam-column elements to support collapse prediction without increased modeling complexity. [ABSTRACT FROM AUTHOR]

This paper investigates the effects of different factors on the performance of nonlinear model updating for a seven-story shear wall building model. The accuracy of calibrated models using different data features and modeling assumptions is studied by comparing the time and frequency responses of the models with the exact simulated ones. Simplified nonlinear finite element models of the shear wall building are calibrated so that the misfit between the considered response data features of the models and the structure is minimized. A refined FE model of the test structure, which was calibrated manually to match the shake table test data, is used instead of the real structure for this performance evaluation study. The simplified parsimonious FE models are composed of simple nonlinear beam-column fiber elements with nonlinearity infused in them by assigning generated hysteretic nonlinear material behaviors to uniaxial stress–strain relationship of the fibers. Four different types of data features and their combinations are used for model calibration: (1) time-varying instantaneous modal parameters, (2) displacement time histories, (3) acceleration time histories, and (4) dissipated hysteretic energy. It has been observed that the calibrated simplified FE models can accurately predict the nonlinear structural response in the absence of significant modeling errors. In the last part of this study, the physics-based models are further simplified for casting into state-space formulation and a real-time identification is performed using an Unscented Kalman filter. It has been shown that the performance of calibrated state-space models can be satisfactory when reasonable modeling assumptions are used. [ABSTRACT FROM AUTHOR]

• A framework for post-earthquake response assessment of Pagoda temples is developed and outlined. • Lidar data are used for post-earthquake geometry and damage (crack) quantification. • Dynamic characterization tests informed the computational model development. • The Applied Element Method is compared to the Finite Element Method for a historic masonry pagoda style temple. This paper presents a linear applied element method (AEM) modeling approach for investigating the effects of the Mw 7.8 2015 Gorkha Nepal earthquake on a historical Pagoda temple. The impact of the earthquake is also investigated using linear FEM models and the results from both modeling approaches are compared. The numerical models are developed and calibrated using pre- and post-earthquake data collected from ambient vibration testing, lidar scans and data processing, and visual damage assessment. The numerical results indicate that the linear AEM models are as reliable as the finite element method (FEM) models to predict the modal response of the case study temple. In addition, the AEM models can potentially be further developed to estimate the damage from future earthquakes through nonlinear analyses. The present study not only informs the present health status of the masonry temple, but it also estimates how acceleration at the base of the temple is propagated through the height of the temple through comparison of floor response spectra, which could provide valuable insights into the force distribution over the height of the temple for the design of future retrofits. [ABSTRACT FROM AUTHOR]