胶层厚度对胶连接接头承载力的影响机理与控制

Mechanism of layer thickness on bearing capacity of adhesive bonding joints and control

为了明晰胶层厚度对胶连接接头承载力的影响机理,采用试验、数值模拟和理论分析相结合的方法研究了胶连接接头承载力与胶层厚度的关系,据此提出了控制技术,并通过试验证明了该技术的有效性。试验发现,随着胶层厚度的增加,初期承载力增加,但是进一步增加胶层厚度,接头破坏模式由剪切破坏变为剥离破坏,承载力明显下降。研究表明,当胶层较薄时,剪应力是接头破坏的控制因素,胶层厚度增加会降低剪应力集中,故承载力提高;而当胶层厚度增加到一定程度时,剥离应力成为接头破坏的控制因素,剥离应力明显增加,故承载力下降。

Based on experiment, FEM simulation and theoretic analysis, a systematical research was con- ducted to clarify the mechanism of the layer thickness on the bearing capacity of the aclhesive bonding joints. Accordingly, a control technology was put forward for adhesive bonding joints and verified by ex- periment. The experiment shows that the initial bearing capacity increases when the layer thickens,but the peeling destruction occurs rather than the shear failure, and that the bearing capacity declines obviously when the layer further thickens. It is found that the shear stress is the main controlling factor with a thin- ner layer and that the peeling stress is the main with a thicker one. The stress concentration relaxes with the layer thickening when it is thin, so the bearing capacity increases. When the layer is thick enough, the peeling stress increases obviously, so the bearing capacity shows a declining tendency with the layer thickening.