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Modeling of Coupled-Fields Problem in Materials Processing with Ultrasonic Vibrations. Chunbo (Sam) Zhang, Leijun Li. Materials Processing & Testing Laboratory. Mechanical & Aerospace Engineering Department. Utah State University. Supported by NSF Grant DMI-0522908. Introduction.
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Modeling of Coupled-Fields Problem in Materials Processing with Ultrasonic Vibrations Chunbo (Sam) Zhang, Leijun Li Materials Processing & Testing Laboratory Mechanical & Aerospace Engineering Department Utah State University Supported by NSF Grant DMI-0522908
Introduction • A revolutionary process technology that uses sound to merge layers of metal drawn from featureless foil stock • A complicated process with coupled mechanical and thermal fields under ultrasonic wave. • Produces true metallurgical bonds with full density • Works with a variety of metals
Benefits of UC • Low process heat enables electronics embedding • Non-destructive, fully-encapsulating fiber embedding • Complex internal geometries • Fully enclosed, sealed internal cavity creation and object embedding • Dissimilar material joining • Rapid manufacturing
Schematic and Device of UC • SolidicaTM Form-Action ultrasonic consolidation system purchased by Utah State University Schematic of UC Process
Applications of UC 3-D Complex Geometries Metal-Matrix Composites Real-time Sensing (Non-invasive, Non-destructive) Metal Composite Shields (Dissimilar Metal Joining)
ANSYS Model for UC Simulation 3-D Thermo-Mechanical Coupled Dynamic Model (a) solid model, (b) meshed model
ANSYS Simulation Conditions • Normal pressure: 1800 N • Vibration amplitude: 16 µm • Vibration frequency: 20 KHz • Preheat temperature : 300 oF
Governing Equations in ANSYS for UC Linear Material Behavior Von-Mises Yielding Criteria Plastic Strain equation
Governing Equations in ANSYS for UC Isotropic Hardening Rule Transient Dynamic Equation for a Linear Structure
Governing Equations in ANSYS for UC Conduction and Convection Heat Flow
Simulation Results – Temperature Field Distribution of Temperature at the 700th Vibration Cycle (X-Y Plane, oF)
Simulation Results – Plastic Strain Field Distribution of von-Mises Plastic Strain at the 700th Vibration Cycle (X-Y Plane)
Conclusions • The friction heat flux at contact surface increases initially and decreases in the later period of ultrasonic bonding. • In the plastic region, three concentration areas occur at the contact surface, one in the central and other two at the two extremes of the sonotrode vibration.