Stress distribution, strength and the effects of eccentric load path in single-lap adhesive joints have been investigated. Also, the characteristics of acoustic emission with surface pretreatment and strength were studied for the evaluation of joint strength. In this work, aluminium alloy 2024-T3 clad was used as adherend material and Araldite AW 106(resin) & HV 953U(hardener) as adhesive material. The stress concentration in the joints with considering the bending moment was higher at both edges of overlap than that with neglecting it. The max. shear stresses showed nearly same value in the joints with same overlap length and different adherend thickness. On the other hand, the max. shear stress was increased with the increase of overlap length in the joints with same adherend thickness. This is considered to be caused by the different residual stress and plastic zone size. There were intimate relationships between surface pretreatment, shear strength, failure mode and the characteristics of Acoustic emission. The etched specimens showed the highest strength. The weaker the adhesive joints were, the more they released AE at earlier stage of load application. In addition, total AE release was higher in poor joints than in good joints at the same small load. The peak amplitude generated in strong adhesive joints was higher than that generated in weak adhesive joints. This was caused by the different modes of fracture (cohesive or adhesive).
Single-lap adhesive joints에서 응력분포, 파괴기준, 하중 전달편차에 의한 영향을 조사하였으며 Acoustic emission을 이용한 강도평가를 위해 표면처리방법 및 강도에 따른 AE특성을 연구하였다. Adherend 및 Adhesive 재료는 알루미뉴움 합금 2024-T3 clad, Araldite AW 106(resin), HV 953 U(hardener )를 각기 사용하였다. 굽힘 모우멘트를 고려했을 때의 응력은 고려하지 않았을 때 보다 Overlap양단에서 더 크게 나타났으며, Overlap길이가 동일하나 adherend 두께가 다를 경우 최대 전단응력은 동일하여 탄성해와 잘 일치되었다. adherend 두께가 동일하나 overlap길이가 다를 경우 최대 전단응력은 길이에 따라 증가하였는데 이는 overlap 양단의 소성영역 및 curing시의 shrinkage에 의한 잔류응력에 기인한다. 시편의 표면처리 방법, 강도, AE 특성은 상호 밀접한 관련이 있었으며 etching한 시편이 최대강도를 보였다. 약한 Adhesive joint의 경우 AE는 강한 Adhesive joint에서보다 작은 하중에서 먼저 방출되었으며 동일한 하중이면서 적은 하중에서의 총 AE양은 약한 adhesive joint에서 더 많이 방출되었다.
Etching한 시편에서 방출한 peak amplitude는 etching하지 않은 시편에서 방출한 peak amplitude보다 컸는데 이는 파괴가, 약한 joint의 경우 adhesive failure, 강한 joint의 경우 cohesive failure에 의해 지배되었기 때문이다.
