Patent ID: 6186011
Filing Date: 2001-02-13
Classification: B23K,G01N

Abstract:
A method of analyzing spot welded sheet metal structures subjected to forces that promote one or more basic failure modes of either shear tension, in-plane rotation, coach peel, normal tension, or any combination of such basic modes, the method comprising the steps of:(a) providing spot-welded sheet metal test coupons for analysis of the selected failure mode for the structure to be analyzed and subjecting such test coupons to progressively increasing forces that eventually achieve failure in the selected failure mode to thereby generate measured load and displacement test data;(b) analyzing such test data from the non-combined failure mode coupons to derive and extract spot weld strength and stiffness information;(c) establishing a computer math model for simulating each spot welded failure mode of the structure and populating the database thereinto to enable simulated physical tests of the structure;(d) creating a cumulative-damage failure criterion for the spot welded structure that ratios (i) resultant strength from the populated math model for selected combinations of load and selected combinations of time and structure thickness with (ii) strength information derived from the measured test data; and(e) solving such criterion by use of such resultant strength information to determine whether the criterion indicates failure for the combination of resultant strength and other values selected.