Design of Iosipescu Shear Test for Applying to a Bi-Modulus Ceramic-Fiber-Reinforced SiO2 Aerogel

作者：Sun Yantao; Shi Duoqi; Yang Xiaoguang^*

来源：Journal of Testing and Evaluation, 2014, 42(5): 1288-1295.

DOI：10.1520/JTE20130023

• SiO2 aerogel
• finite-element analysis
• bi-modulus
• shear test
• notch

Tension and compression tests were conducted on a ceramic-fiber-reinforced SiO2 aerogel (CFRSA). The material exhibits different tension and compression modulus, i.e., bi-modulus. The objective of present research is to establish guidelines for preparing shear tests of this CFRSA. Finite-element analysis (FEA) on various Iosipescu specimens is presented for four bi-modulus materials, including the CFRSA. It is found that the major concerns for specimen design of bi-modulus materials are: the uniformity of shear stress and the longitudinal normal stress concentration at notch tips. These concerns are all dependent on material properties. For material with E-t numerically close to E-c, the normal stress concentration near notch tips is of less significance. However, for material with high tension-compression asymmetry, including this CFRSA, the normal stress concentration near notch tips is significant. The round-notch specimen with small normal stress concentration seems to be favorable for these materials.

• 出版日期2014-9
• 单位北京航空航天大学