金属面复合材料波纹夹层结构多次冲击性能及其剩余强度

Performance and residual strength of metal-faced composite corrugated sandwich structure under multiple impacts

  • 摘要: 金属面复合材料波纹夹层结构结合了金属耐冲击和复合材料高比强度/比刚度的优点,是一种优异的新型结构形式,在服役过程中夹层结构会遭受多次冲击工况,而其多次冲击损伤模式及损伤后剩余强度规律目前尚未明确。为此通过多次冲击试验和CT无损扫描分析方法,对其在低速冲击动力学响应、内部失效模式、载荷-位移特性以及能量吸收特征进行了深入研究,并在此基础上,通过对冲击后的试件开展平面压缩试验,对多次冲击后的剩余压缩强度及失效模式进行了分析。结果表明:首次冲击造成了大部分的伤害,随着冲击次数的提高将导致夹层结构的吸能性降低,抗冲击性下降。多次冲击中,夹层结构的损伤模式以芯材的基体开裂、分层和纤维断裂为主,大能量的多次冲击总是造成更大的损伤。此外,随着冲击次数的增多,损伤累积接近饱和,剩余压缩强度趋近阈值。

     

    Abstract: The metallic-faced composite corrugated sandwich structure, which combines the impact resistance of metals with the high specific strength and stiffness of composites, represents an exemplary form of innovative construction. During its service life, the sandwich structure is subjected to multiple impact conditions, yet the patterns of damage from repeated impacts and the post-damage residual strength are not yet clearly understood. To address this, a comprehensive study was conducted through a series of impact tests and CT non-destructive scanning analyses, delving into the dynamic response to low-velocity impacts, internal failure modes, load-displacement characteristics, and energy absorption features. Furthermore, based on these findings, plane compression tests were carried out on impacted specimens to analyze the residual compressive strength and failure modes after multiple impacts. The findings indicate that the initial impact inflicts the most damage, and with increasing impact frequency, the energy-absorbing capacity and impact resistance of the sandwich structure diminish. In multiple impacts, the predominant damage modes in the sandwich structure include matrix cracking, delamination, and fiber breakage in the core material, with higher energy impacts invariably causing more extensive damage. Moreover, as the number of impacts increases, the accumulation of damage approaches saturation, and the residual compressive strength trends towards a threshold value.

     

/

返回文章
返回