AISI NHERI Diaphragm Supplement June 30, 2020 Update to AISI Hernan - PowerPoint PPT Presentation

AISI NHERI Diaphragm Supplement June 30, 2020 Update to AISI Hernan Castaneda 1 and Kara D. Peterman 2 1 Graduate Research Assistant, University of Massachusetts Amherst 2 Assistant Professor, University of Massachusetts Amherst

General Project Update • We are all healthy and productive! • Frontloading modeling efforts during Work From Home Journal paper 1 (joist-ledger connections) on path to publication – coming soon This summer, extended to full diaphragm system models  predictions for future specimens • Cantilever test rig (supported by SDI + Verco/Vulcraft) fabrication delayed due to COVID, design complete Movement happening now things are opening up a bit • Lab @UMass re-opened 06/22 at 25% capacity • UCSD “latest and greatest” timeline: testing (in 6 DOF) Dec 2021/Jan 2022.

Brack Lab (UMass): Diaphragm Test Rig Top view Fix End Pin Connection Strong Floor Specimen Frame Actuator Roller Free End Front view

Brack Lab (UMass): Actuator and Roller Connection Bracket Roller Attachment Actuator Support Beam

Brack Lab (UMass): Rollers • Roller support aimed at 10% of actuator capacity: 10 kips Prevent Uplift Roller Dolly, Swivel Platform, 25000 lb. 3 ¼" Wheel Dia.

Brack Lab (UMass): Rig – Fix Connection Rig-Fixed Support

Brack Lab (UMass): Rig – Actuator Connection Rig-Actuator

Brack Lab (UMass): Rig - Attachments Rig-Specimen Rig-Actuator Actuator-Support Beam Rig-Fixed Support

Brack Lab (UMass): Rig – Specimen Width Flexibility

Brack Lab (UMass): Test Rig [15’X15’] – Motion • 10 in Stroke • Δz = 0.26 in • Tilt angle = 1 ° Click to play videos

Brack Lab (UMass): Test Rig [10’X15’] – Motion • 10 in Stroke • Δz = 0.26 in • Tilt angle = 1 ° Click to play videos

Brack Lab (UMass): Test Rig Estimation of Weight, W: Fix Transverse Beam Support Test Rig Frame W Component (lbs) (Kg) Roller Free Beam 2834 1286 Support Fix Beam Fix Beam 2558 1160 2 Transverse Beam 4019 1823 Total 9412 4269 Supports + Attachments + Plates W Component (lbs) (Kg) Actuator Support 1002 455 Actuator 2 Fix Support 1223 555 Free Beam Support Roller Support 551 250 Total 2776 1259 Note: Weight is calculated assuming a density value of 0.2836 lbs/in 3 - Nominal thickness of components varies between ¾” and ½” - - Some dimensions are approximated

Diaphragm FEM 9/16” Deck on CFS Joist: Geometry • A three-dimensional Finite Element Model (FEM) was developed using ABAQUS. Joist Ledger (1200S200-97) (1200T200-97) Ledger (1200T200-97) Clip-Angle (1.5X1.5-54) - ν = 0.3 - E = 29500 ksi • Shell Elements: S4R • Material properties steel: - Fy = 50/60 ksi (EPP)

Diaphragm FEM: Contact Interactions Deck Side-Lap Clip-Angle Deck Joist Web Joist Web Ledger Flange Clip-Angle Ledger Web Ledger Web Joist Flange Ledger Flange Deck Joist Flange - Tangential: - Normal: • Contact behavior: C.O.F. = 0.2 Non-linear penetration pressure

Diaphragm FEM: Fastener Connections • Connector elements: Ledger Flange - Wires Joist Flange (Screw #10) Clip-Angle Multi-Linear Joist Web Elastic Node Node (Screw #10) j i Failure Damage Clip-Angle Connector Element Behavior Ledger Web Fastener Pull-Out 97-54 3 (Screw #10) Pull-Out P peak (Castaneda 2020) P 3 Force, P [kN] 2 z P 2 x Shear P 1 (Tao 2017) 9754-R1 1 9754-R2 Ledger Flange 9754-R3 ABAQUS Shear P final y Joist Flange 0 (Tao 2017) 0 6 12 18 (Screw #10) Displacement, δ [mm] Fastener elastic behavior Experimental response

Diaphragm FEM: Fastener Connections Side-Lap Connection @ 12” o.c. (Screw #10) Support Connection (Screw #12) Pattern 30/4 Edge Connection @ 8” o.c. 30” (Screw #12) Support Connection Pattern

Diaphragm FEM: Loading and Boundary Conditions Load strips [Uy=Uz=0; Ux=Applied Displacement] End Ledger Web [Uz=0] P x z “Fix” strips @ 2 ft o.c. [Ux=Uy=Uz=0] End Ledger Web [Uz=0]

Stress Contour Diaphragm FEM: Results Failure @ Side-Lap Fastener Failure @ Corner Fastener Connector Resultant Force

Diaphragm FEM: Results • Effect on fastener modeling shear behavior: - Ductile: Consider post peak experimental response - Brittle: Fastener suddenly fails upon reaching peak experimental response

Diaphragm FEM: Results Field Connection @15” Edge Connection @7.5” 3/8”

Diaphragm FEM: Results Joist @ 2ft Warping Joist @ 4ft Warping Buckling Joist @ 8ft

Diaphragm FEM: Results Joist Ledger Specimen 10ftX8ft: Joist @ 8ft

Comments / Questions? Email me: kdpeterman@umass.edu