Data processing: structural design – modeling – simulation – and em – Simulating nonelectrical device or system – Mechanical
Reexamination Certificate
2000-10-10
2004-07-27
Paladini, Albert W. (Department: 2125)
Data processing: structural design, modeling, simulation, and em
Simulating nonelectrical device or system
Mechanical
C703S005000, C219S13700R, C228S101000, C228S103000
Reexamination Certificate
active
06768974
ABSTRACT:
TECHNICAL FIELD
This invention relates generally to a method for determining a model for a welding simulation and, more particularly, to a method for incorporating models of aspects of the welding simulation into a constitutive model, and a model thereof.
BACKGROUND ART
During a welding process, residual stresses and distortions are introduced into materials being welded as a result of the high temperatures involved with welding. These stresses and distortions may alter characteristics of the welded material in an adverse manner. For example, the structural integrity of the material may be compromised.
It is often desired to have the capability to predict the stresses and distortions associated with the welding process. This information may then be used to modify the welding process to minimize stresses and distortions during subsequent welds. A well known method to predict stresses and distortions is to simulate the welding process in a model. For example, it is common to use finite element analysis to model the welding process, and several commercial software packages are available.
However, a significant disadvantage of known welding process model packages is that they cannot adequately model some of the unique phenomena associated with welding. For example, these packages cannot account for history annihilation caused by melting/remelting as different weld passes are deposited. The inability of the known model packages to account for unique welding phenomena results in inaccurate computations. Therefore, it is desired to model the welding process by including unique phenomena, such as history annihilation, phase transformation, strain hardening, and the like. It is also desired to model the welding process in a method that is efficient and saves computational time and power; for example, by determining various models of the phenomena associated with the welding process, and incorporating these models into a constitutive model of the overall process.
In addition, many of the same unique phenomena are introduced during a thermal cutting process, such as cutting by means of oxyfuel, plasma, or laser. The models used for a welding process may also be used for a thermal cutting process.
The present invention is directed to overcoming one or more of the problems as set forth above.
DISCLOSURE OF THE INVENTION
In one aspect of the present invention a method for determining a model for a welding simulation is disclosed. The method includes the steps of determining a history annihilation model of a material being welded, determining a strain hardening model of the material being welded, determining a three-dimensional virtual elements detection model of the material being welded, and incorporating the above models into a constitutive model for the welding simulation.
In another aspect of the present invention a method for determining a model for a welding simulation is disclosed. The method includes the steps of determining a history annihilation model of a material being welded, determining a phase transformation model of the material being welded, determining a three-dimensional virtual elements detection model of the material being welded, and incorporating the above models into a constitutive model for the welding simulation.
In another aspect of the present invention a method for determining a model for a welding simulation is disclosed. The method includes the steps of determining a history annihilation model of a material being welded, determining a strain hardening model of the material being welded, determining a phase transformation model of the material being welded, determining a large deformation model of the material being welded, determining a three-dimensional virtual elements detection model of the material being welded, and incorporating the above models into a constitutive model for the welding simulation.
In another aspect of the present invention a constitutive model for a welding simulation is disclosed. The model includes a history annihilation model of a material being welded, a strain hardening model of the material being welded, a three-dimensional virtual elements detection model of the material being welded, and means for incorporating the above models into a constitutive model for the welding simulation.
In another aspect of the present invention a constitutive model for a welding simulation is disclosed. The model includes a history annihilation model of a material being welded, a phase transformation model of the material being welded, a three-dimensional virtual elements detection model of the material being welded, and means for incorporating the above models into a constitutive model for the welding simulation.
In another aspect of the present invention a constitutive model for a welding simulation is disclosed. The model includes a history annihilation model of a material being welded, a strain hardening model of the material being welded, a phase transformation model of the material being welded, a large deformation model of the material being welded, a three-dimensional virtual elements detection model of the material being welded, and means for incorporating the above models into a constitutive model for the welding simulation.
REFERENCES:
patent: 4596917 (1986-06-01), Nied et al.
patent: 4998663 (1991-03-01), Cakmak et al.
patent: 5552575 (1996-09-01), Doumanidis
patent: 406186141 (1994-07-01), None
Harold Chestnut, Systems Engineering Tools, 1965, John Wiley & Sons, pp. 108-109.*
A Constitutive Model for Welding Process Simulation Using Finite . . . Brust, et al., Battelle Memorial Institute.
A Model for Predicting Residual Stresses In Metal Cutting, Nagoya, 1990.
Applied Mechanics in grinding. VI. Residual stresses and surface hardening b coupled thermo-. . . , Nerac, Inc, 1999.
Brust Frederick W.
Dong Pingsha
Dong Yi
Nanjundan Ashok
Zhang Jinmiao
Caterpillar Inc
Fahlberg Robin S.
Lundquist Steve D.
Paladini Albert W.
LandOfFree
Method for determining a model for a welding simulation and... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Method for determining a model for a welding simulation and..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Method for determining a model for a welding simulation and... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3217020