Virginia Tech
    • Log in
    View Item 
    •   VTechWorks Home
    • ETDs: Virginia Tech Electronic Theses and Dissertations
    • Masters Theses
    • View Item
    •   VTechWorks Home
    • ETDs: Virginia Tech Electronic Theses and Dissertations
    • Masters Theses
    • View Item
    JavaScript is disabled for your browser. Some features of this site may not work without it.

    Topology Optimization of Steel Shear Fuses to Resist Buckling

    Thumbnail
    View/Open
    Avecillas_JA_T_2019.pdf (60.54Mb)
    Downloads: 1081
    Date
    2019-02-01
    Author
    Avecillas, Javier Andres
    Metadata
    Show full item record
    Abstract
    Shear-acting structural fuses are steel plates with cutouts subjected to in-plane lateral displacements during extreme loading events such as earthquakes, that dissipate energy through localized shear or flexural yielding mechanisms. Although previous studies have reported that fuses with specific geometry can develop a stable hysteretic behavior, their small thickness makes them prone to buckling, reducing strength and energy dissipation capacity. In this work, topology optimization using genetic algorithms is performed to find optimized shapes for structural fuses with a square domain and constant thickness. The objective function uses the fuse's shear buckling load VB obtained from a 3D linear buckling analysis, and shear yield load VY obtained from a material nonlinear, but geometrically linear 2D plane-stress analysis. The two analyses are shown to be computationally efficient and viable for use in the optimization routine. The variations VY/VB=0.1,0.2,0.3 are investigated considering a target volume equal to 30%, 40% and 50% the fuse's original volume. A new set of optimized topologies are obtained, interpreted into smooth shapes, and evaluated using finite elements analyses with models subjected to monotonic and cyclic displacements histories. It was found that the drift angle when out-of-plane buckling occurs can be controlled using the VY/VB ratio, with optimized topologies buckling at drift angles (when subjected to a cyclic displacement protocol) as large as 9% as compared to 6% for previously studied fuses.
    General Audience Abstract
    Shear-acting structural fuses are steel plates with cutouts that dissipate energy during extreme loading events such as earthquakes. These structural fuses have a fixed edge and an opposing edge subjected to in-plane lateral displacements. Although previous studies have reported that fuses with specific geometry have a good cyclic performance, their small thickness makes them prone to bend or buckle, reducing strength and energy dissipation capacity. Considering a structural fuse with a square domain and constant thickness, a mathematical method called topology optimization is implemented to optimize the distribution of material with the goal of controlling the amount of yielding in the structural fuse before it buckles. The optimization routine uses the fuse’s shear buckling capacity (VB) and shear yield strength (VY ) obtained from relative simple and computationally inexpensive procedures that are also valid to characterize the potential for buckling in a structural fuse. The variations VY /VB = 0.1, 0.2, 0.3 are investigated considering a target volume equal to 30%, 40% and 50% the fuse’s original volume. A set of optimized topologies are interpreted into smooth shapes and evaluated using finite elements analyses. It was found that the drift angle when out-of-plane buckling occurs can be controlled by using the VY /VB ratio, with optimized topologies buckling at drift angles (when subjected to a cyclic displacement protocol) as large as 9% as compared to 6% for previously studied fuses.
    URI
    http://hdl.handle.net/10919/87407
    Collections
    • Masters Theses [20950]

    If you believe that any material in VTechWorks should be removed, please see our policy and procedure for Requesting that Material be Amended or Removed. All takedown requests will be promptly acknowledged and investigated.

    Virginia Tech | University Libraries | Contact Us
     

     

    VTechWorks

    AboutPoliciesHelp

    Browse

    All of VTechWorksCommunities & CollectionsBy Issue DateAuthorsTitlesSubjectsThis CollectionBy Issue DateAuthorsTitlesSubjects

    My Account

    Log inRegister

    Statistics

    View Usage Statistics

    If you believe that any material in VTechWorks should be removed, please see our policy and procedure for Requesting that Material be Amended or Removed. All takedown requests will be promptly acknowledged and investigated.

    Virginia Tech | University Libraries | Contact Us