Kwon Bae Jun, Kim Chan-Jung
Stability, DNV AS Norway, 1363 Oslo, Norway.
School of Mechanical Engineering, Pukyoung National University, Busan 48513, Republic of Korea.
Polymers (Basel). 2024 Sep 19;16(18):2642. doi: 10.3390/polym16182642.
The orientation of carbon fibers significantly affects the dynamic properties of unidirectional carbon-based composites (UCBCs), with variations under different static loads. A previous study analyzed changes in the modal parameters of UCBC structures by using the static load influential factor (SLIF). This study introduces a revised SLIF, derived from a simplified formulation that accounts for shifts in resonance frequency and the in-phase relationship between static load and modal response. The revised SLIF is theoretically linked to the modal participation factor in UCBC structures. The dynamic behavior of UCBCs was studied across six modes-four bending and two torsional-using specimens with five carbon fiber orientations, from 0 to 90 degrees. The revised SLIF showed significant effects in two robust specimens, #1 and #2, and an isotropic SUS304 specimen subjected to uniaxial pre-static load, with resonance frequency variations under 0.16%. In contrast, the original SLIF gave negligible results in the fifth mode due to a damping term, which, when multiplied by the resonance frequency, led to an undetectable indicator. Therefore, the revised SLIF more effectively captures the static load's impact on UCBC dynamic behavior compared with the original method.
碳纤维的取向显著影响单向碳基复合材料（UCBC）的动态性能，在不同静态载荷下会有所变化。先前的一项研究通过使用静态载荷影响因子（SLIF）分析了UCBC结构模态参数的变化。本研究引入了一种修正的SLIF，它源自一个简化公式，该公式考虑了共振频率的变化以及静态载荷与模态响应之间的同相关系。修正后的SLIF在理论上与UCBC结构中的模态参与因子相关联。使用具有从0到90度的五个碳纤维取向的试样，研究了UCBC在六种模态（四种弯曲和两种扭转）下的动态行为。修正后的SLIF在两个坚固的试样#1和#2以及一个承受单轴预静态载荷的各向同性SUS304试样中显示出显著效果，共振频率变化在0.16%以下。相比之下，由于一个阻尼项，原始SLIF在第五种模态中给出的结果可忽略不计，该阻尼项与共振频率相乘后导致一个无法检测到的指标。因此，与原始方法相比，修正后的SLIF能更有效地捕捉静态载荷对UCBC动态行为的影响。
