Fracture Prediction of Navy Steels Fracture Prediction of Navy Steels A System Approach A System Approach Tomasz Wierzbicki Presentation at the NNR Review Meeting, St. Louis, June 2nd, 2004 Impact & Crashworthiness Lab, MIT Impact & Crashworthiness Lab, MIT MIT team members: Professor Frank McClintock Dr. Yingbin Bao Mr. Young-Woong Lee Mr. Xiaoqing Teng Mr. Yuanli Bai
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Fracture Prediction of Navy SteelsFracture Prediction of Navy SteelsA System ApproachA System Approach
Tomasz WierzbickiPresentation at the NNR Review Meeting, St. Louis, June 2nd, 2004
Impact & Crashworthiness Lab, MITImpact & Crashworthiness Lab, MIT
MIT team members: Professor Frank McClintockDr. Yingbin BaoMr. Young-Woong LeeMr. Xiaoqing TengMr. Yuanli Bai
Impact & Crashworthiness Lab, MITImpact & Crashworthiness Lab, MIT
Damaged Area as a Measure of Ships SurvivabilityDamaged Area as a Measure of Ships Survivability
USDHUSDH
x
y
L0
0.0 0.1 0.2 0.3 0.4 0.50.0
0.1
0.2
0.3
0.4
0.5
Water rushes into the hole
Adpative (ηcb = 0.0002)
USDH (ηcb = 0.0761)
ηcb : Normalized cracked area of bottom plate
ξ0 = 0.5; V = 1.14; τ = 0.55; Bottom face plate; 1/4 model
Nor
mal
ized
dis
tanc
e ζ
= y
/ L0
Normalized distance ξ = x / L0
MIT Simulation
Impact & Crashworthiness Lab, MITImpact & Crashworthiness Lab, MIT
Fracture at Six Different LevelsFracture at Six Different Levels
5. Bay
4. Stiffeners & Panels
1. Microvoids
3. Specimens & Weldment
2. Unit Cube with defects
6. Ship
VirginiaTech/MIT
MIT
Michigan/MIT
5. Bay
4. Stiffeners & Panels
1. Microvoids
3. Specimens & Weldment
2. Unit Cube with defects
6. Ship
VirginiaTech/MIT
MIT
Michigan/MIT
MURI project : Development of blast resistance adaptive ship structures (Harvard University and MIT)Level 3 & 4
NNR project : Fracture prediction of navy steels (MIT through ATI )Level 2 & 3
NNR Project : Design of ships for survivability (jointly between Virginia Tech., UMich and, MIT )Level 1, 2, 5, & 6
ONR Project : DURIP instrumentation grant (awarded to MIT)Level 3
Impact & Crashworthiness Lab, MITImpact & Crashworthiness Lab, MIT
Deliverables under NNR Funding Deliverables under NNR Funding through ATI ( 7/03through ATI ( 7/03--6/04)6/04)
Five technical reports (out of which, three have been submitted to major international journals)
Installation of three new pieces of equipment in the Impact and Crashworthiness Lab for fracture testing (3-D optical strain measuring device, Instron 9250NH DynatupDrop Tower, Zeiss microscope for fracture surface examination)
Completion of the design of 50 kN biaxial testing machine (joint project with Instron)
Design and manufacture of a universal specimen for fracture testing under combined loading
Study of physical aspects of ductile fracture (Report #112, 120)Study of numerical aspects of ductile fracture (Report # 114,
127)
Impact & Crashworthiness Lab, MITImpact & Crashworthiness Lab, MIT
Deliverables under NNR Funding through ATI ( 7/03-6/04) (cont.)
Presentations and discussions of the industrial approach to fracture at :•Sandia National Labs Albuquerque and Livermore •Stanford Research Institute •Applied Research Associates •Weidlinger Associates•Earnst Mach Institute in Freiburg, Germany•BMW R&D Center in Munich, Germany•EuroPAM Conference in Mainz, Germany•AmeriPAM Conference in Warren, MI•ABAQUS User Meeting in Cambridge, MA
Two new US citizen graduate students admitted
Impact & Crashworthiness Lab, MITImpact & Crashworthiness Lab, MIT
Publications of the MIT Team Completed for NNR Funding through ATI ( 7/03-6/04)
Necking, Fracture Initiation, and Crack Propagation in Flat Tensile Specimen, Y.W. Lee, T. Wierzbicki and Y. Bao, February, 2004, Impact andCrashworthiness Lab., Report #114 (to be submitted to Mechanics of Materials)
Bridgman Revisited: On the History Effects on Ductile Fracture, T. Wierzbicki and Y. Bao, January, 2004, Impact and Crashworthiness Lab., Report #112 (Submitted to Journal of the Mechanics and Physics of Solids)
Evaluation of the Wilkins (and other) Fracture Model, Y. Bao, Y.W. Lee and T. Wierzbicki, May 2004 Impact and Crashworthiness Lab., Report #120 (Submitted to Engineering Fracture Mechanics)
A Comparative Study of Shell Element Deletion and Element Split, H. Alsos, June, 2004, Impact and Crashworthiness Lab., Report #127 (MS Thesis)
Prediction of High Velocity Impact Fracture of Large Structural Systems, T. Wierzbicki, March, 2004, Impact and Crashworthiness Lab., Report #118 (Summary Report)
Impact & Crashworthiness Lab, MITImpact & Crashworthiness Lab, MIT
Equipment Recently Purchased under DURIPEquipment Recently Purchased under DURIPInstrumentation Grant to ICLInstrumentation Grant to ICL
Zeiss microscope
Instron 9250NH Dynatup Drop
Tower
3-D optical strain
measuring device
Impact & Crashworthiness Lab, MITImpact & Crashworthiness Lab, MIT
Custom Made 50 Custom Made 50 kNkN Biaxial Testing RigBiaxial Testing Rig
Impact & Crashworthiness Lab, MITImpact & Crashworthiness Lab, MIT
New Types of Specimens for Biaxial TestingNew Types of Specimens for Biaxial Testing
2nd generation 3rd generation
Impact & Crashworthiness Lab, MITImpact & Crashworthiness Lab, MIT
Testing to FractureTesting to Fracture
Steel specimen under tension
Al 2024 in combined shear/compression
Impact & Crashworthiness Lab, MITImpact & Crashworthiness Lab, MIT
Fracture vs. No FractureFracture vs. No Fracture
Round specimens subjected to hydrostatic pressure and tension
Impact & Crashworthiness Lab, MITImpact & Crashworthiness Lab, MIT
Experimentally Determined Fracture LocusExperimentally Determined Fracture Locus
12 34 5
6 7 8
9 10 11
Bao-Wierzbicki fracture locus
Impact & Crashworthiness Lab, MITImpact & Crashworthiness Lab, MIT
Calibration of BW ModelCalibration of BW ModelEvaluation of Calibration Constant Evaluation of Calibration Constant DDc c (high stress triaxiality)(high stress triaxiality)