INTEGRITY OF ADHESIVE JOINTS

INHOMOGENEITIES AND/OR DEGRADATION IN ENGINEERING MATERIALS, PARTICULARLY ADHESIVE JOINTS, PRESENTS AN AREA OF CONSTANT AGGRAVATION TO BOTH DESIGNERS AND MANUFACTURERS. PREVIOUS RESEARCH HAS SHOWN THAT THE RESPONSE OF STRUCTURAL COMPONENTS TO IMPOSE VIBRATIONS CAN BE USED TO CHARACTERIZE THEIR INTEGRITY. THIS PROPOSAL OUTLINES A RESEARCH PROGRAM TO EXPLORE THE POSSIBILITY OF USING THE PREVIOUSLY DEVELOPED IMPULSE FREQUENCY RESPONSE VIBRATION TECHNIQUE AS A MECHANISTIC TOOL FOR EVALUATION OF THE STRUCTURAL INTEGRITY OF ADHESIVE BONDED JOINTS. PHASE I OF THE PROGRAM WOULD BE A FEASIBILITY STUDY TO VALIDATE THE VIBRATION INDUCED RESPONSE IN A MATERIAL WILL PROVIDE A PRACTICAL MEANS OF APPLYING MECHANICAL STRESSES THROUGH SMALL AMPLITUDE VIBRATION AND EVALUATING THEIR EFFECTS ON ADHESIVE BOND INTERFACES. THE TECHNIQUE HAS THE POTENTIAL FOR USING DURING MANUFACTURE (BY SETTING "ACCEPT-REJECT" LIMITS IN THE QUALITY OR PROCESS CONTROL OPERATIONS) AND FOR MONITORING DEGRADATION DURING THE SERVICE LIFE OF ADHESVIE JOINTS. THE UTILITY AND SIMPLICITY OF THIS APPROACH IS A DEFINITE ASSET FOR FULFILLING THE DEMANDS OF A NON-DESTRUCTIVE IN-SITU TEST TECHNIQUE IN VARIOUS APPLICATIONS.