The Carbon Nanotubes Effect into Single-lap Joint Failure Modes and Load Capacity: a Macromechanical Analysis

This study investigates the influence of the adhesive (epoxy resin) thickness and the dispersions of non-functionalized carbon based nanostructures (carbon nanotubes - CNT) on mechanical properties of single-lap bonded joints. To achieve this goal, three CNT concentrations (0.5%, 1.0% and 2.0% m/m); and three different bondline thicknesses (0.05 mm, 0.15 mm and 0.40 mm) were evaluated. The mechanical properties were measured using the apparent shear tensile test, based on ASTM D5868. The results showed that the addition of 1.0 wt% CNTs improved the interface strength, leading to an increase on delaminated areas in failure region up to 55.36% and also improving the peak force up to 13.85%. Decrease in adhesive thickness from 0.40 mm to 0.05 mm promoted a stress redistribution inside adhesive layer improving the peak force up to 13.91%. CNT seems to promote changes in failure modes, light fiber tear (LFT) failure significantly increases up to 45.96%, indicating that interface strength between adhesive and adherent was improved.

本研究探究了胶粘剂（环氧树脂，epoxy resin）厚度与非功能化碳基纳米结构（碳纳米管，CNT）的分散性对单搭接胶接接头力学性能的影响。为实现该研究目标，实验设置了三种碳纳米管浓度（0.5%、1.0%与2.0% m/m）以及三种不同胶层厚度（0.05 mm、0.15 mm与0.40 mm）开展评估。力学性能通过基于ASTM D5868标准的表观剪切拉伸试验进行测定。结果显示，添加1.0 wt%的碳纳米管可提升界面强度，使失效区域的分层面积最高提升55.36%，同时将峰值力最高提升13.85%。将胶粘剂厚度从0.40 mm降至0.05 mm，可促进胶层内部的应力重分布，使峰值力最高提升13.91%。碳纳米管似乎会改变失效模式，轻纤维撕裂（LFT）失效占比最高提升45.96%，表明胶粘剂与被粘物之间的界面强度得到了改善。