hybrid simulation of structural collapse n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Hybrid Simulation of Structural Collapse PowerPoint Presentation
Download Presentation
Hybrid Simulation of Structural Collapse

Loading in 2 Seconds...

play fullscreen
1 / 18

Hybrid Simulation of Structural Collapse - PowerPoint PPT Presentation


  • 104 Views
  • Uploaded on

Hybrid Simulation of Structural Collapse. Andreas Schellenberg , Tony Yang, Stephen Mahin and Boza Stojadinovic. Department of Civil and Environmental Engineering University of California, Berkeley. Motivation. Outline of Presentation.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Hybrid Simulation of Structural Collapse' - allen-bruce


Download Now An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
hybrid simulation of structural collapse

Hybrid Simulation of Structural Collapse

Andreas Schellenberg, Tony Yang,

Stephen Mahin and Boza Stojadinovic

Department of Civil and Environmental Engineering

University of California, Berkeley

outline of presentation
Outline of Presentation
  • Hybrid Simulation and OpenFresco middleware
  • Second-Order Effects and Structural Collapse
  • Implementation in OpenSees and OpenFresco
  • Structural Collapse of Portal-Frame
  • Summary and Conclusions
hybrid simulation

Advantages:

Loading (RHS) is defined analytically

Dynamic testing of full-scale specimens withfewer restrictions on size, weight and strength

Quasi-static testing equipment sufficient

Geographically distributed for testingexceeding the capacity of one lab

Incorporate geometric nonlinearities into analytical portion of hybrid model

Hybrid Simulation
  • Dynamic Loading:
  • Seismic
  • Wind
  • Blast/Impact
  • Wave
  • Traffic
  • Static Loading:
  • Gravity
  • Prestress

analytical model of structural energy dissipation and inertia

physical model of

structural resistance

analytically add nonlinear geometric effects to measured resisting forces

hybrid simulation1
Hybrid Simulation
  • Model the well understood parts of a structure in a finite element program on one or more computers, including nonlinearity, multi-support excitation and soil-structure interaction
  • Leave the construction and testing of the highly nonlinear and/or numerically hard to model parts of the structure in one or more laboratories
  • Can be considered as a conventional finite element analysis where physical models of some portions of the structure are embedded in the numerical model
implementation strategy

Proper numerical model uncertain

NUMERICAL ELEMENT 1

NUMERICAL ELEMENT 3

NUMERICAL ELEMENT 2

?

Implementation Strategy
  • Embed test specimen(s) in an existing computational framework of users choice

ADMINISTRATIVE

FUNCTIONS

RECORDERS

COMMUNICATION

Typical features of an analysis framework

NODAL

GEOMETRY

BOUNDARY

CONDITIONS

MASS AND

DAMPING

PROPERTIES

LOADING

ELEMENT TYPES

AND LOCATIONS

SOLUTION

METHODS

ELEMENT PROPERTIES

STATE DETERMINATION

implementation strategy1

NUMERICAL ELEMENT 1

NUMERICAL ELEMENT 2

OpenFresco

OpenFresco

LABORATORY

CONTROLLERS

AND DAQS

Laboratory

Implementation Strategy
  • Embed test specimen(s) in an existing computational framework of users choice

ADMINISTRATIVE

FUNCTIONS

RECORDERS

COMMUNICATION

Typical features of an analysis framework

NODAL

GEOMETRY

BOUNDARY

CONDITIONS

MASS AND

DAMPING

PROPERTIES

LOADING

ELEMENT TYPES

AND LOCATIONS

SOLUTION

METHODS

ELEMENT PROPERTIES

Define element as an “Experimental Element”

STATE DETERMINATION

EXPERIMENTAL ELEMENT 1

slide8

Simulation of Structural Collapse

  • On shaking tables, simulation of collapse is dangerous and expensive
  • In hybrid simulations
    • Gravity loads and resulting geometric nonlinearities can be modeled analytically
      • Therefore, no complex active or passive gravity load setups are necessary
    • Actuator movements will limit displacements during collapse (safety)
      • Thus, there is no need to protect expensive test equipment from specimen impact
    • Only critical, collapse-sensitive elements of a structure need to be physically modeled
slide9

Second-Order Effects

  • Definition: effect of loads on the deformed geometry (satisfy equilibrium in deformed configuration)
  • P-Δ: change of global geometry (structural level)
  • P-δ: change of member geometry (element level)
  • P-M, P-V interaction (section level) also local buckling
implementation in a hybrid model
Implementation in a Hybrid Model
  • Physical portion of the model:
    • Test material and cross-section level response
  • Analytical portion of the model:
    • Apply the gravity and/or prestress loads
    • Provide the geometric transformations such that the second-order effects due to axial loads are accounted for
    • Model the rest of the structure
slide12

Structural Collapse of Portal Frame

  • Crd-Trans: P-Delta, Corotational
  • ExpElements: EEBeamColumn2d
  • ExpSetups: ESOneActuator
  • ExpControl: ECxPCtarget
  • SACNF01: pga = 0.906g
  • Properties of Model:
  • NDOF = 8(2 with mass)
  • Period: T1 = 0.49 sec
  • Damping: ζ1 = 0.05
  • P = 50% of φPn
slide13

OpenSees/OpenFresco Details

OpenSees Finite Element Model

OpenFresco

Middleware

xPC-Target real-time

Predictor-Corrector

MTS 493 real-time Controller

Physical Specimen

in μNEES Lab

slide14

Hybrid Simulations

Without Gravity Load

With Gravity Load

conclusions
Conclusions
  • Benefits:
    • Second-order effects can be simulated without applying the axial force on the physical specimen
    • The specimens and test setups are less expensive
    • The physical setups are protected from falling structural components
  • Shortcomings:
    • Interaction of axial force and element resistance at the local level is not yet accounted for (local buckling, P-M interaction)
    • Rate effects are not accounted for
questions thank you

Questions?Thank you!

http://openfresco.neesforge.nees.org

The development of OpenFresco has been sponsored in parts by the National Science Foundation through grants from the NEES Consortium, Inc.