Effects of voids on the mechanical strength and ultrasonic attenuation of laminated composites
Effects of voids on the mechanical strength and ultrasonic attenuation of laminated composites
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DOI：
10.1177/002199839703100303
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发表时间：
1997-01-01
影响因子：
2.9
通讯作者：
Jeong, H
中科院分区：
文献类型：
--
作者：
Jeong, H
本文研究了含大量孔隙的复合材料层合板的力学强度和超声衰减特性。分别采用单向胶带和机织预浸料制备了石墨纤维增强复合材料试样，测量了其层间剪切强度和频率依赖性超声衰减，并对其微观结构进行了研究。测得的强度和衰减斜率被发现不仅取决于空隙含量，但与复合材料的预浸料结构的空隙的几何形状。一个剪切断裂准则类似于Mar-Lin方程的缺口拉伸断裂应力被成功地用来关联多孔层合板的断裂强度。单向层合物显示出比织物层合物高得多的空隙敏感性，即，对于给定的空隙含量，剪切强度降低更多，衰减斜率更高。结果表明，孔隙含量可以估计从测量的衰减斜率和衰减斜率和多孔复合材料层合板的剪切强度之间存在良好的相关性。
The effects of voids on the mechanical strength and ultrasonic attenuation have been investigated on a number of laminated composite systems containing a wide range of void content. Graphite fiber reinforced specimens were fabricated both from unidirectional tape and woven fabric prepreg and their interlaminar shear strength and frequency dependent ultrasonic attenuation were measured together with a careful study of microstructure. The measured strength and attenuation slope were found to depend not only on the void content but on the void geometry associated with the prepreg structure of composites. A shear fracture criterion similar to the Mar-Lin equation for notched tensile fracture stresses was used successfully to correlate the fracture strength of porous laminates. The unidirectional laminates showed much higher void sensitivity than the fabric laminates, i.e., more reduction in shear strength and higher attenuation slope for a given void content. It was shown that the void content may be estimated from the measured attenuation slope and that a good correlation exists between the attenuation slope and the shear strength of porous composite laminates.