摘要
为了解夹芯复合材料T型接头在弯曲疲劳载荷作用下的损伤特征模式及剩余强度特性,以疲劳加载试验机和万能材料试验机为测试平台,开展了该型接头的弯曲疲劳试验以及疲劳加载前后的静力弯曲破坏对比试验。通过接头疲劳加载前的静力弯曲破坏试验,获取了结构初始破坏载荷并观测了损伤特征模式。试验研究结果表明,在弯曲疲劳载荷作用下,接头结构刚度呈现渐进退化特征且随疲劳载荷峰值的上升呈加速趋势,接头的疲劳损伤模式主要为水平基座夹芯板两侧简支边界位置泡沫芯材的剪切损伤,泡沫芯材力学性能的退化导致结构刚度的渐进式下降。进一步的试验结果对比分析表明,该型接头的疲劳安全峰值载荷可取为结构初始损伤载荷的70%,在疲劳安全峰值载荷范围内并经历105次弯曲疲劳循环后,接头的初始刚度和极限承载弯矩与疲劳承载前基本相当。
To understand the fatigue damage behavior and residual strength of composite sandwich T-joint subject to bending loads, the bending fatigue tests were performed, including the static bending failure tests before and after the fatigue tests on fatigue loading test machine and universal material testing machine. The static bending failure tests were carried out before fatigue loading to obtain the initial failure load of the structure, and the damage characteristic mode was observed. The experimental results show that the stiffness of the composite sandwich T-joint presents a progressive degradation, and the acceleration trend increases with the rise of the peak load; The shear damage of foam core is the main damage mode of the composite sandwich T-joint on the side of the horizontal panel~ Thedegradation of mechanical property of the foam leads to a progressive decrease in the structural stiffness. Further comparative analysis shows that the stiffness and the ultimate bearable bending moment of the composite sandwich T-joint after 10s fatigue loading circles are approximately equal to that before fatigue loading is imposed under the condition that the fatigue peak load is 70% of the initial failure load.
出处
《西安交通大学学报》
EI
CAS
CSCD
北大核心
2017年第9期125-130,共6页
Journal of Xi'an Jiaotong University
基金
国家自然科学基金资助项目(51479205)
