Muflikhun Muhammad Akhsin, Fiedler Bodo
Mechanical and Industrial Engineering Department, Gadjah Mada University, Jl. Grafika No. 2, Yogyakarta 55281, Indonesia.
Center for Advanced Manufacturing and Structural Application (CAMSE), Gadjah Mada University, Jl. Grafika No. 2, Yogyakarta 55281, Indonesia.
Polymers (Basel). 2022 Oct 14;14(20):4322. doi: 10.3390/polym14204322.
The present study explores the failure and surface characteristics of Glass Fiber-Reinforced Polymers (GFRP). Stepwise loading was applied in this study to understand the multi-static loading effect on the laminates before final failure. The loading was set three times to reach 10 kN with loading-unloading movement before final load until failure. The results showed that the angle of the GFRP UD laminates' position significantly impacts the system's failure. The results were analyzed using theoretical calculation experiment analysis, and then the failure sample was identified using ASTM D3039 standard failure. The laminates with 0° layer on edge ([0/90] laminates) underwent preliminary failure before final failure. The mechanism of stepwise loading can be used to detect the effect of preliminary failure on the laminates. The [0/90] laminates are subjected to stress concentration on the edge due to fiber alignment and discontinued fibers in the 0-degree direction. This fiber then fails due to debonding between the fiber and the matrix. The laminates' strength showed that [90/0] specimens have an average higher strength with 334.45 MPa than the [0/90] laminates with 227.8 MPa. For surface roughness, the value of Ra increases more than six times in the 0° direction and three times in the 90° direction. Moreover, shore D hardness showed that the hardness was decreased from 85.6 SD then decreased to 70.4 SD for [0/90] and 65.9 SD for [90/0]. The matrix debonding, layer delamination and fiber breakage were reported as the failure mode behavior of the laminates.
本研究探讨了玻璃纤维增强聚合物（GFRP）的失效及表面特性。本研究采用逐步加载来了解在最终失效前多层板的多静态加载效应。加载设置三次，在最终加载直至失效前通过加载-卸载运动达到10 kN。结果表明，GFRP单向层压板的位置角度对系统失效有显著影响。使用理论计算实验分析对结果进行分析，然后根据ASTM D3039标准失效来识别失效样本。边缘带有0°层的层压板（[0/90]层压板）在最终失效前经历了初步失效。逐步加载机制可用于检测初步失效对层压板的影响。由于纤维排列以及0度方向上纤维的间断，[0/90]层压板在边缘处受到应力集中。然后，这种纤维由于纤维与基体之间的脱粘而失效。层压板的强度表明，[90/0]试样的平均强度更高，为334.45 MPa，而[0/90]层压板的平均强度为227.8 MPa。对于表面粗糙度，在0°方向上Ra值增加了六倍多，在90°方向上增加了三倍。此外，邵氏D硬度表明，[0/90]层压板的硬度从85.6 SD下降到70.4 SD，[90/0]层压板的硬度下降到65.9 SD。基体脱粘、层间分层和纤维断裂被报告为层压板的失效模式行为。
