Numerical Simulations of Thermal Detection of Disbonds in Lap Joints
The detection of disbonds in riveted lap joints is of increasing interest to the aerospace community. For some cases a disbonded lapjoint gives rise to cracks at the rivets due to stress concentrations in the aluminum skin when the lapjoints are loaded. When a number of these cracks exist they have been known to suddenly link up and cause sudden failure of the part. Thermographic detection of these disbonds has advantages over other methods in that it is a noncontacting, quantitative method which can inspect large areas in a short period of time. By even application of heat to the outer surface of the lap joint, details of the inner structure become thermographically detectable. A disbond between layers of a laminated structure will prevent heat from penetrating from the surface layer to the subsurface layers and will result in an increase in surface temperature over the disbond.
KeywordsLawrence Livermore National Laboratory Heating Pulse Data Reduction Technique Flux Heat Input Quantitative Nondestructive Evaluation
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