CAJ | 학술논문

胶接接头中总存在胶瘤,由于建模复杂,胶接接头有限元分析中胶瘤常被忽略.但胶瘤能减少峰值应力,提高结构强度和刚度.为此,提出一种简化的胶接有限元模型,即用壳单元代表胶瘤,体单元代表被粘体和胶层,并用弹性理论建立壳单元等效厚度公式.以体单元精细模型结果作为对比的真实解,考察五种载荷工况下,单搭接头简化有限元模型的胶层应力和刚度.分析表明,壳单元等效厚度公式正确,胶接简化有限元模型精度高,可用于诸如汽车等大型结构中;用壳单元简单模型可定量分析胶瘤大小和形状对接头应力和总体刚度性能的影响.
효접접두중총존재효류,유우건모복잡,효접접두유한원분석중효류상피홀략.단효류능감소봉치응력,제고결구강도화강도.위차,제출일충간화적효접유한원모형,즉용각단원대표효류,체단원대표피점체화효층,병용탄성이론건립각단원등효후도공식.이체단원정세모형결과작위대비적진실해,고찰오충재하공황하,단탑접두간화유한원모형적효층응력화강도.분석표명,각단원등효후도공식정학,효접간화유한원모형정도고,가용우제여기차등대형결구중;용각단원간단모형가정량분석효류대소화형상대접두응력화총체강도성능적영향.
Spew-fillet is always present in an adhesive joint, but is usually neglected in structural analysis due to its finite element(FE) modeling complexity. As known, the presence of spews can reduce peak stresses and therefore increase the joint strength and stiffness. To this end, a simplified finite element model was developed for adhesive bonded joints, in which the spew-fillet was modeled by means of the equivalent shell elements and an adherend/adhesive-layer through solid elements. The equivalent thickness formula of the spew shell-element was presented based on the classical elasticity theory. A comparison between the simplified analyses and detailed 3D models was made by a linear elastic finite element analysis with isotropic materials (MSC.NASTRAN). To evaluate the accuracy of such simplified modeling approach under various loading conditions, the adhesive stress and stiffness of the bonded joint were analyzed respectively. The simplified formula is verified in the numerical experiment and a fairly good agreement is observed between the simple and the refined model results,which could be applied to large-scale FE models such as automotive structures. The coarse model proposed here enables quantification of the effects of the size and shape of the spew on the stress and stiffness performance of adhesive bonded joints.