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<p class="MsoNormal" style="margin:0in;font-size:12pt;font-family:"Calibri",sans-serif"><b>Webinar: Higher-Mode Force Demands in Systems Employing Elastic
Strongback Spines<span></span></b></p>

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<p class="MsoNormal" style="margin:0in;font-size:12pt;font-family:"Calibri",sans-serif">NHERI Lehigh Seminar Series<span></span></p>

<p class="MsoNormal" style="margin:0in;font-size:12pt;font-family:"Calibri",sans-serif">March 31, 2021 | 12:00 pm – 1:00 pm EST<span></span></p>

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<p class="MsoNormal" style="margin:0in;font-size:12pt;font-family:"Calibri",sans-serif">Speaker: <a href="https://cce.oregonstate.edu/simpson" style="color:rgb(5,99,193);text-decoration:underline">Barbara
Simpson</a>, Assistant Professor, Oregon State University<b><span></span></b></p>

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<p class="MsoNormal" style="margin:0in;font-size:12pt;font-family:"Calibri",sans-serif">Register <a href="https://www.designsafe-ci.org/learning-center/training/workshops/lehigh-ef/2021/higher-mode-force-demands/" style="color:rgb(5,99,193);text-decoration:underline">online
at DesignSafe</a>.<span></span></p>

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<p class="MsoNormal" style="margin:0in;font-size:12pt;font-family:"Calibri",sans-serif">About the webinar:<span></span></p>

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<p class="MsoNormal" style="margin:0in;font-size:12pt;font-family:"Calibri",sans-serif">Research has identified the potential advantages of pivoting
seismic force-resisting systems that employ an elastic spine, or “strongback”.
The strongback is represented by a truss or stiff column that is designed to
remain essentially elastic, thus providing an elastic load path to
re-distribute seismic demands across the building height. As such, strongback
systems are expected to result in more uniform drift distributions, reduced
peak inelastic demands, and improved design flexibility compared to
conventional seismic force-resisting systems.<span></span></p>

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<p class="MsoNormal" style="margin:0in;font-size:12pt;font-family:"Calibri",sans-serif">However, since the strongback is designed to remain elastic
in every mode, systems employing strongback spines can be highly influenced by
higher- mode force and acceleration demands that are not well-constrained by
inelastic response. These higher-mode demands can affect acceleration-sensitive
nonstructural components. A series of investigations were aimed at
understanding the nonlinear dynamic response of strongback systems, including
higher-mode mitigation strategies.<span></span></p>

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<p class="MsoNormal" style="margin:0in;font-size:12pt;font-family:"Calibri",sans-serif">At the E-Defense shake-table in Japan, an international team
of U.S. and Japanese researchers tested a moment- resisting frame (MRF)
retrofitted with an elastic spine. The specimen included acceleration-sensitive
hospital equipment. The MRF-spine system was then subsequently modified with
force-limiting connections to alleviate higher- mode accelerations through
controlled yielding. Results demonstrate the influence of higher-mode effects
on strongback and similar systems.<span></span></p>

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<p class="MsoNormal" style="margin:0in;font-size:12pt;font-family:"Calibri",sans-serif">Find more details and register <a href="https://www.designsafe-ci.org/learning-center/training/workshops/lehigh-ef/2021/higher-mode-force-demands/" style="color:rgb(5,99,193);text-decoration:underline">on
the DesignSafe website</a>.</p><p class="MsoNormal" style="margin:0in;font-size:12pt;font-family:"Calibri",sans-serif"><br></p><p class="MsoNormal" style="margin:0in;font-size:12pt;font-family:"Calibri",sans-serif"><br></p><div style="text-align:center"><img src="cid:ii_kmghg9540" alt="Lehigh.png" style="margin-right: 0px;" width="319" height="80"><br></div>

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