Patent ID: 7702494

Claim:
A method of simulating motions of a rigid body from a set of known rigid body orientations, using a finite element analysis model, the method comprising: (a) receiving, in a computer system having a finite element analysis application module installed thereon, a set of known rigid body orientation time history definitions; (b) updating a current simulation time for current solution cycle; (c) converting the definitions to a set of direction cosine time histories, when the definitions are other than direction cosine; (d) obtaining a direction cosine matrix for the current solution cycle by interpolating the set of direction cosine time histories at the current simulation time; (e) calculating time derivative of the direction cosine matrix and corresponding angular velocity matrix; (f) calculating the rigid body's motions at the current solution cycle using the finite element analysis model and the calculated angular velocity matrix and the interpolated direction cosine matrix, wherein the calculated rigid body's motions are saved into a file on a storage device and are graphically displayed on a monitor based on user's instructions; and (g) if the current simulation time is less than a pre-defined total simulation time, repeating (b) to (g).