Accession Number:

ADA288291

Title:

Process Control of Microstructure in Manufacturing.

Descriptive Note:

Final rept. 14 Sep 90-31 Dec 93,

Corporate Author:

WRIGHT STATE UNIV DAYTON OH

Personal Author(s):

• Grandhi, Ramana V.

Report Date:

1994-06-01

Pagination or Media Count:

252.0

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.

Descriptors:

• *VISCOPLASTICITY
• *MICROSTRUCTURE
• *MANUFACTURING
• *PROCESSING
• * FORGING
• THERMAL PROPERTIES
• VELOCITY
• COUPLING(INTERACTION)
• LINEAR SYSTEMS
• INPUT
• OUTPUT
• CONTROL
• REQUIREMENTS
• METHODOLOGY
• OPTIMIZATION
• MODELS
• TEMPERATURE
• PARAMETERS
• COMPOSITE MATERIALS
• FINITE ELEMENT ANALYSIS
• DEFORMATION
• CRITICAL TEMPERATURE
• DIES
• NODES
• QUADRATIC PROGRAMMING
• REDUCTION
• REGULATORS
• STRAIN RATE
• TIME
• VARIABLES
• VARIATIONS
• BILLETS(MATERIALS)
• LOAD DISTRIBUTION

Subject Categories:

• Inorganic Chemistry
• Manufacturing and Industrial Engineering and Control of Production Systems
• Manufacturing and Industrial Engineering and Control of Production Systems
• Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE