一种考虑胶瘤的胶接简化有限元模型:应力与刚度分析  

STRESS AND STIFFNESS ANALYSIS OF A SIMPLIFIED ADHESIVE BONDED FINITE ELEMENT MODEL CONSIDERING SPEW-FILLETS

作　　者：赵波[1] 岳鹏 吕毅宁[3] 田黎明 孙永祥 

机构地区：[1]清华大学汽车工程系汽车安全与节能国家重点实验室,北京100084 [2]驻航天二院二○六所军事代表室,北京100854 [3]中国船级社技术研究开发中心,北京100007

出　　处：《机械强度》2009年第6期939-946,共8页Journal of Mechanical Strength

摘　　要：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。Spew-fillet is always present in an adhesive joint, bat 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-fiUet 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 isotropie 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 struetures. 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.

关 键 词：胶瘤 简化模型 应力 刚度 胶接 单搭接头 有限元分析 

分 类 号：TG494[金属学及工艺—焊接] TB115[理学—数学]