The Experts below are selected from a list of 2424 Experts worldwide ranked by ideXlab platform

Tara C Hutchinson - One of the best experts on this subject based on the ideXlab platform.

B W Schafer - One of the best experts on this subject based on the ideXlab platform.

  • modeling seismic response of a full scale cold formed Steel Framed Building
    Engineering Structures, 2017
    Co-Authors: Jiazhen Leng, Kara D Peterman, Stephen G Buonopane, Guanbo Bian, B W Schafer
    Abstract:

    Abstract The objective of this paper is to present finite element modeling protocols and validation studies for the seismic response of a two-story cold-formed Steel-Framed Building with oriented strand board sheathed shear walls. Recently, shake table testing of this Building was completed by the authors. The Building provides an archetype for modern details of cold-formed Steel construction, and provides benchmarks for the seismic response of the Building system, subsystem, and components. The seismic response of Buildings Framed from cold-formed Steel has seen little study in comparison with efforts on isolated members and shear walls. Validated Building-scale models are needed to expand our understanding of the seismic response of these systems. Finite element models corresponding to the archetype Building during its various test phases are developed in OpenSees and detailed herein. For cold-formed Steel Framed Buildings accurate seismic models require consideration of components beyond the isolated shear walls, e.g. the stiffness and capacity of the gravity framing is included in the model. Such decisions require model refinement beyond what is typically performed and details for completing this effort accurately and efficiently are described herein. In addition, nonstructural components, including exterior sheathing of the gravity framing, interior gypsum sheathing for the shear walls and gravity framing, and interior partition walls, are included in the Building model based on nonlinear surrogate models that utilize experimental characterization of member-fastener-sheathing response. Comparisons between the developed models and testing for natural period, story drift, accelerations, and foundation hold-down forces validate the model. Performance of the tested archetype Building is better than predicted by design or typical engineering assumptions. The model developed herein provides insights into how the Building achieves its beneficial performance and will be used to further quantify the lateral resistance of each subsystem and the extent of their coupling. In addition, the protocols used to develop the model herein provide a first examination of the necessary modeling characteristics for wider archetype studies of cold-formed Steel-Framed Buildings and the development and substantiation of seismic response modification coefficients.

  • design component and system reliability in a low rise cold formed Steel Framed commercial Building
    Engineering Structures, 2016
    Co-Authors: B H Smith, B W Schafer, Sanjay R Arwade, Cristopher D Moen
    Abstract:

    Abstract Target structural reliabilities are implicit in most modern design codes and yet efficiency of design and construction as well as the presence of constraints on the design space mean that structural components in a Building system may have as-designed reliabilities that differ from the target reliabilities. This paper presents an investigation of this phenomenon through a detailed examination of the two story cold-formed Steel Framed Building designed and tested as part of the CFS-NEES project and seeks to use this case study to elucidate features of the component and system reliabilities that may prevail in typically designed Buildings. Specifically, for the gravity load system of the second floor and the lateral force resisting system the demand to capacity ( D / C ) ratios and reliabilities ( β ) are calculated. The results of these calculations illustrate the excess and highly variable D/C ratios and reliabilities that result from efficient design procedures. Since the ultimate goal of structural design is to ensure performance of the structural system at a target level of reliability the influence of excess and variable component reliability on reliability of the lateral force resisting system is examined by making assumptions about series and parallel-type interaction of the floor diaphragm and shear walls. Finally, discussion is presented about the role of load combinations and their associated coefficients of variation in determining component and system reliability in a cold-formed Steel Framed Building. Future considerations include more robust, high fidelity, modeling of the system effects and evaluation of excess capacity and variability of reliability across suites of other Building designs and structural systems such as roof trusses.

  • experimental seismic response of a full scale cold formed Steel Framed Building ii subsystem level response
    Journal of Structural Engineering-asce, 2016
    Co-Authors: Kara D Peterman, Matthew Stehman, R L Madsen, Stephen G Buonopane, Narutoshi Nakata, B W Schafer
    Abstract:

    AbstractThe objective of this paper is to employ the results from the extensive instrumentation installed on recently tested full-scale cold-formed Steel (CFS)-Framed Buildings to reveal a deeper understanding of the behavior of the Building under seismic excitations. In particular, this paper complements a companion paper that focuses on system-level design and response. Here, utilizing strategically located string potentiometers, strain gauges, and accelerometers, the responses of the walls and diaphragms are isolated from the overall Building response and studied. The interaction of shear walls along a wall line, as well as across stories is studied through measured data on strains in hold-down anchors, strains on floor-to-floor strap connecting shear-wall chord studs, and displacements across shear-wall sheathing and openings. The behavior of the floor diaphragm is studied through displacements measured perpendicular to the plane of one wall of the Building and accelerometers throughout the floor of t...

  • modeling the seismic response of cold formed Steel Framed Buildings model development for the cfs nees Building
    2013
    Co-Authors: Jiazhen Leng, B W Schafer, Stephen G Buonopane
    Abstract:

    The objective of this paper is to investigate the response of a cold-formed Steel Framed Building subjected to earthquake excitation primarily through nonlinear time history analysis employing the incremental dynamic analysis (IDA) framework. The two-story archetype Building from the Cold-Formed Steel ‐ Network for Earthquake Engineering Simulation (CFS-NEES) project is analyzed using OpenSees. In the current ‘state-of-the-art’ model, fully nonlinear hysteretic pinching models for the shear walls are parameterized directly based on shear wall test data conducted as an earlier phase of the CFS-NEES project. Nonlinear behavior of the shear wall hold downs in tension and compression, shear anchors, and rigid diaphragm are also captured in the model. The normalized far field ground motion suite from FEMA P695 is employed as the input excitation. A series of analyses using scaled ground motions are completed up through large enough drift levels to insure collapse in the Building models. The IDA procedure provides information about the performance of the Building under general earthquake loading so that drift and other limits for collapse prevention (i.e. loss of stability for the Building) can be explored. Comparison of the predicted inelastic base shear vs. elastic base shear provides a direct understanding of the relationship between IDA analysis and seismic response modification factors (e.g., R or more specifically R d ) as utilized in design practice and within the FEMA P695 procedure. Further refinement of the Building model is underway; particularly, with respect to modeling the gravity framing, diaphragm, and non-structural elements. The fully developed model will be calibrated with test data from full scale shaking table tests of this Building to be conducted in the summer of 2013. Modeling and analysis guidelines based on the sensitivity of the results to model fidelity will be developed as a resource to promote simulation in seismic design of cold-formed Steel Buildings.

Xiang Wang - One of the best experts on this subject based on the ideXlab platform.

Brian J Meacham - One of the best experts on this subject based on the ideXlab platform.

Kara D Peterman - One of the best experts on this subject based on the ideXlab platform.

  • modeling seismic response of a full scale cold formed Steel Framed Building
    Engineering Structures, 2017
    Co-Authors: Jiazhen Leng, Kara D Peterman, Stephen G Buonopane, Guanbo Bian, B W Schafer
    Abstract:

    Abstract The objective of this paper is to present finite element modeling protocols and validation studies for the seismic response of a two-story cold-formed Steel-Framed Building with oriented strand board sheathed shear walls. Recently, shake table testing of this Building was completed by the authors. The Building provides an archetype for modern details of cold-formed Steel construction, and provides benchmarks for the seismic response of the Building system, subsystem, and components. The seismic response of Buildings Framed from cold-formed Steel has seen little study in comparison with efforts on isolated members and shear walls. Validated Building-scale models are needed to expand our understanding of the seismic response of these systems. Finite element models corresponding to the archetype Building during its various test phases are developed in OpenSees and detailed herein. For cold-formed Steel Framed Buildings accurate seismic models require consideration of components beyond the isolated shear walls, e.g. the stiffness and capacity of the gravity framing is included in the model. Such decisions require model refinement beyond what is typically performed and details for completing this effort accurately and efficiently are described herein. In addition, nonstructural components, including exterior sheathing of the gravity framing, interior gypsum sheathing for the shear walls and gravity framing, and interior partition walls, are included in the Building model based on nonlinear surrogate models that utilize experimental characterization of member-fastener-sheathing response. Comparisons between the developed models and testing for natural period, story drift, accelerations, and foundation hold-down forces validate the model. Performance of the tested archetype Building is better than predicted by design or typical engineering assumptions. The model developed herein provides insights into how the Building achieves its beneficial performance and will be used to further quantify the lateral resistance of each subsystem and the extent of their coupling. In addition, the protocols used to develop the model herein provide a first examination of the necessary modeling characteristics for wider archetype studies of cold-formed Steel-Framed Buildings and the development and substantiation of seismic response modification coefficients.

  • experimental seismic response of a full scale cold formed Steel Framed Building ii subsystem level response
    Journal of Structural Engineering-asce, 2016
    Co-Authors: Kara D Peterman, Matthew Stehman, R L Madsen, Stephen G Buonopane, Narutoshi Nakata, B W Schafer
    Abstract:

    AbstractThe objective of this paper is to employ the results from the extensive instrumentation installed on recently tested full-scale cold-formed Steel (CFS)-Framed Buildings to reveal a deeper understanding of the behavior of the Building under seismic excitations. In particular, this paper complements a companion paper that focuses on system-level design and response. Here, utilizing strategically located string potentiometers, strain gauges, and accelerometers, the responses of the walls and diaphragms are isolated from the overall Building response and studied. The interaction of shear walls along a wall line, as well as across stories is studied through measured data on strains in hold-down anchors, strains on floor-to-floor strap connecting shear-wall chord studs, and displacements across shear-wall sheathing and openings. The behavior of the floor diaphragm is studied through displacements measured perpendicular to the plane of one wall of the Building and accelerometers throughout the floor of t...