ABSTRACT

Adhesive bonding is increasingly used in numerous industrial branches (aeronautics, space, etc.) for the many advantages this technique features. The quality of the adhesive bonds depends on diversified factors, and bonding defects within the joints are common. These defects may take the shape of pores, of various sizes, which are a possible threat to the good mechanical strength of the joints. These pores may create unwanted stress concentrations, and they are susceptible to locally weaken the adhesive joints. As they are created during the bonding process, the hypothesis that the bonding and curing conditions should influence their properties is well-founded. In order to validate this assertion, adhesively bonded samples were made, for different adhesives and different curing cycles. In particular, the influence of the peak temperature reached during the curing cycle was studied. The pores in the joints were then observed and studied using X-ray microtomography. The performances of the segmentation technique developed for the data processing were studied beforehand on synthetic data, in order to identify the limitations of the suggested methodology and to quantify the uncertainty on the computed quantities. It was found that a higher curing temperature may induce noticeable pore growth phenomena (mainly dilation and coalescence). In particular, this growth seems to be predominant halfway-through the thickness of the joints, resulting in an observable decrease in the effective section.

摘要

粘合剂越来越多地用于众多工业领域（航空、航天等）.) 该技术具有许多优点。粘接的质量取决于多种因素，接头内的粘接缺陷很常见。这些缺陷可能呈现出各种大小的孔隙形状，这可能对接头的良好机械强度构成威胁。这些孔可能会产生不需要的应力集中，并且它们容易局部削弱粘合接头。由于它们是在粘合过程中产生的，因此粘合和固化条件会影响其特性的假设是有根据的。为了验证这一说法，针对不同的粘合剂和不同的固化周期制作了粘合样品。特别地，研究了在固化循环期间达到的峰值温度的影响。然后使用 X 射线显微断层扫描观察和研究关节中的孔隙。为数据处理开发的分割技术的性能事先在合成数据上进行了研究，以确定所建议方法的局限性并量化计算量的不确定性。研究发现，较高的固化温度可能会引起明显的孔隙增长现象（主要是膨胀和聚结）。特别是，这种增长似乎在接头厚度的一半处占主导地位，导致有效截面的明显减少。以确定建议方法的局限性并量化计算量的不确定性。研究发现，较高的固化温度可能会引起明显的孔隙增长现象（主要是膨胀和聚结）。特别是，这种增长似乎在接头厚度的一半处占主导地位，导致有效截面明显减少。以确定建议方法的局限性并量化计算量的不确定性。研究发现，较高的固化温度可能会引起明显的孔隙增长现象（主要是膨胀和聚结）。特别是，这种增长似乎在接头厚度的一半处占主导地位，导致有效截面明显减少。