Process Control of Microstructure in Manufacturing.

Abstract

This report presents a systematic methodology for the design of optimal process parameters for forging processes. The procedure for construction of a state space model utilizing nonlinear rigid-viscoplastic finite element formulation is developed. A coupled state space model is built to represent the deformation and thermal behavior of the material, with nodal velocities and nodal temperatures as the state variables, and die velocity as input to the system. The output variables of the state space system are the effective strain rate and critical nodal temperature. The linear quadratic regulator (LQR) theory with finite time control is used in designing the ram velocity and initial die temperature. Model reduction schemes are adopted in generating reduced order analytical models from the full size state space representation. The methodology developed is demonstrated on axisymmetric and plane strain forging cases. The performance of the procedure is evaluated using measures such as temperature and strain rate variation within the billet, load requirement, and total process time.

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Document Details

Document Type
Technical Report
Publication Date
Jun 01, 1994
Accession Number
ADA288291

Entities

People

  • Ramana V. Grandhi

Organizations

  • Wright State University

Tags

Communities of Interest

  • C4I
  • Energy and Power Technologies
  • Ground and Sea Platforms

DTIC Thesaurus Topics

  • Computational Science
  • Construction
  • Control Systems
  • Convection
  • Coordinate Systems
  • Equations Of State
  • Finite Element Analysis
  • Heat Transfer
  • Manufacturing
  • Materials
  • Mechanical Properties
  • Mechanics
  • Phase Transformations
  • Regulators
  • Space Systems
  • Temperature Gradients
  • Two Dimensional

Readers

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  • Structural Dynamics.

Technology Areas

  • Space