胶焊搭接接头的应力分布和疲劳行为研究

考察了胶焊接头焊点区的结构组成和硬度分布，建立了胶焊接头的计算模型，模型中计人了若干结构细节，使之与实际接头更为接近。计算并对比研究了胶焊和点焊、胶焊和胶接接头中的应力。通过疲劳试验获得了三种接头的－Ｎ曲线，研究了三种接头的疲劳性能和断裂特征。结果表明，数值分析所得应力与疲劳性能试验结果及试验现象吻合良好。在电阻点焊接头中采用胶粘剂，可大大改善电阻点焊接头的疲劳性能，而焊点对胶接接头的疲劳性能有不利影响。

STUDIES ON STRESS DISTRIBUTION AND FATIGUE BEHAVIOR OF WELDBONDED LAP SHEAR JOINTS

Structural constituent and hardness distribution of weld spot zone in the weldbonded joints are investigated. A computational model for weldbonded joints is established, which is composed of four parts, i. e. base metal, heat effected zone, nugget and adhesive layer, and several structural details are taken into account in the model, making it more close to actual joint. Stresses in spot welded joints, adhesive bonded joints and weldbonded joints are calculated and studied using the computational model established. Finally, -N curves of these three types of joints are Obtained by high frequency fatigue tests, fatigue behavior and fracture characteristics of the joints are studied. Results show that stresses from numerical analysis are identical with experimental results and phenomena. The application of adhesives in spot welding greatly improves the joint fatigue performance,while the presence of weld spots in adhesive bending has negative effect on joint fatigue performance.