Method of initializing bolt pretension in a finite element analysis

A computer-readable storage medium containing instructions for controlling a computer system to perform initializing bolt pretension independent of axial strain in a finite element analysis for simulating structural responses of a structure with bolted joints included therein by a method comprising:

• defining one or more bolts, each as a beam element in a finite element analysis model of the finite element analysis;
• defining at least one pretension-versus-time curve for specifying desired pretension of said each of the one or more bolts, wherein the at least one pretension-versus-time curve comprises a ramp portion, a desired pretension portion and an optional unloading portion;
• conducting a first series of quasi-static analyses at solution cycles covering the ramp portion of the pretension-versus-time curve in the finite element analysis;
• conducting a second series of quasi-static analyses at solution cycles covering the desired pretension portion of the pretension-versus-time curve in the finite element analysis;
• and
• achieving of the initializing bolt pretension by terminating the second series of quasi-static analyses when either of first and second bolt pretension termination conditions has been detected and determined.

A system for initializing bolt pretension independent of axial strain in a finite element analysis for simulating structural responses of a structure with bolted joints included therein, the system comprising:

• a main memory for storing computer readable code for an application module;
• at least one processor coupled to the main memory, said at least one processor executing the computer readable code in the main memory to cause the application module to perform operations of:
• defining one or more bolts, each as a beam element in a finite element analysis model of the finite element analysis;
• defining at least one pretension-versus-time curve for specifying desired pretension of said each of the one or more bolts, wherein the at least one pretension-versus-time curve comprises a ramp portion, a desired pretension portion and an optional unloading portion;
• conducting a first series of quasi-static analyses at solution cycles covering the ramp portion of the pretension-versus-time curve in the finite element analysis;
• conducting a second series of quasi-static analyses at solution cycles covering the desired pretension portion of the pretension-versus-time curve in the finite element analysis;
• and
• achieving of the initializing bolt pretension by terminating the second series of quasi-static analyses when either of first and second bolt pretension termination conditions has been detected and determined.