FATIGUE SCREENING METHOD

1 . A method comprising:

generating a 3D computer-coded model of a component; and

performing simulations on the model to determine an onset of gross plastic deformation in a plurality of regions of the component;

wherein the model is stored in a computer-readable medium.

2 . A method of claim 1 , wherein the model of the component comprises:

a body; and

a load bearing interface, wherein the load bearing interface is designed to contain pressure or support a load;

wherein the simulations are performed at different pressures or loads on the load bearing interface.

3 . The method of claim 1 , wherein the component is a threaded connection with threads chosen from a group of either one or combination of sharp, ACME, knuckle, square, and other conventionally known shapes of threads.

4 . A method of claim 3 , wherein the plurality of regions comprises at least both of longitudinal ends and middle regions of the threads of the component.

5 . The method of claim 1 , wherein generating the model comprises delineating a mesh overlaid onto the model, wherein the mesh defines a plurality of mesh elements and nodal points at vertices of the mesh elements.

6 . The method of claim 5 , wherein the performing simulations comprises:

defining material properties of the component;

defining boundary conditions of the model;

defining loading conditions on the model; and

using an algorithm implemented in a computer to find an equilibrium solution on the nodal points of the model;

wherein the equilibrium solution comprises a force equilibrium of the nodal points of the model in the boundary conditions and the loading conditions; and

wherein the model at the force equilibrium condition results into a plastically deformed model.

7 . The method in claim 6 , wherein defining boundary conditions further defines stationary nodal points that are fixed during the simulations.

8 . The method in claim 6 , wherein defining loading conditions further defines initial conditions, working loads, and deformation patterns of the simulations of the model.

9 . The method of claim 1 , wherein the onset of gross plastic deformation is defined when a parameter across a region exceeds a maximum contour value obtained by an equation, wherein the region comprises the highest stress concentration.

10 . The method of claim 9 , wherein the parameter is a change in slope of a stress-strain curve during simulations.

11 . A method comprising:

determining an onset of gross plastic deformation of a component by performing simulations on a 3D computer-coded model of a plurality of regions of the component; and

dividing the onset of gross plastic deformation by a safety factor to calculate a working capability load of the model.

12 . The method of claim 11 , wherein the model of the component comprises:

multiple bodies; and

at least one load bearing interface between the multiple bodies.

13 . The method of claim 12 , wherein the plurality of regions comprises at least surfaces of the multiple bodies forming the at least one load bearing interface.

14 . The method in claim 12 , wherein the at least one load bearing interface comprises a threaded connection with threads chosen from a group of either one or combination of sharp, ACME, knuckle, square, and other conventionally known shapes of threads.

15 . The method in claim 12 , wherein the performing simulations comprises:

defining material properties of the multiple bodies;

defining boundary conditions of the model;

defining loading conditions of the model;

using an algorithm implemented in a computer to find an equilibrium solution on nodal points defined on the model;

wherein the equilibrium solution comprises a force equilibrium of the nodal points of the model in the boundary conditions and the loading conditions; and

wherein the model at the force equilibrium condition results into a plastically deformed model.

16 . The method in claim 15 , wherein defining boundary conditions further defines stationary nodal points that are fixed during the simulations.

17 . The method in claim 15 , wherein defining loading conditions further defines initial conditions, working loads, and deformation patterns of the simulations of the model.

18 . The method of claim 11 , wherein the onset of gross plastic deformation is defined when a parameter across a region exceeds a maximum contour value obtained by an equation, wherein the region comprises the highest stress concentration.

19 . The method of claim 18 , wherein the parameter is a change in slope of a stress-strain curve during simulations.

20 . The method of claim 11 further comprises determining if the model is safe under a load by comparing all of onset of gross plastic deformation of the plurality regions of the component.