BF-SHCC动态拉伸性能试验研究

Study on dynamic tensile properties of BF-SHCC

为探讨玄武岩纤维高延性水泥基复合材料(Basalt Fiber Strain-Hardening Cementitious Composites, BFSHCC)动态拉伸性能,自行研发设计了适用于BF-SHCC高速拉伸试验的试件尺寸和连接方式,并采用高速拉伸试验机进行高速拉伸试验;采用电子万能试验机对BF-SHCC进行了低速拉伸试验;研究分析了4种应变率下BF-SHCC动态拉伸性能。结果表明:BF-SHCC在4种应变率下,均表现出应变硬化现象,试件在低速拉伸试验条件下均表现出多缝开裂现象,在高速拉伸试验条件下,表现为单缝开裂破环;BF-SHCC的初裂强度和极限强度均随应变率的增加而增大,初裂强度的应变率敏感性高于极限强度的应变率敏感性;在低速拉伸试验条件下,BF-SHCC的极限延伸率和峰值韧性,随应变率的增加而降低,在高速拉伸试验条件下,BF-SHCC的极限延伸率和峰值韧性有明显提高。

In order to investigate the dynamic tensile properties of BF-SHCC, the size and connection method of the test pieces suitable for the high-speed tensile test of BF-SHCC were independently developed, and a high-speed tensile tester was used in the high-speed tensile test. BF-SHCC was subjected to the low-speed tensile test;the dynamic tensile properties of BF-SHCC under four strain rates were analyzed. The results show that BF-SHCC exhibits strain hardening at four strain rates, and under low-speed tensile testing conditions, the specimen appears multi-slit cracking, and under highspeed tensile test conditions, it appears as a single-slit cracking;the initial crack strength and ultimate strength of the material increase with the increase of the strain rate, and the strain rate sensitivity of the initial crack strength is higher than the strain rate sensitivity of the ultimate strength;under low-speed tensile test conditions, the ultimate elongation and peak toughness of the material decrease with the increase of the strain rate. Under high-speed tensile test condition,the ultimate elongation and peak toughness of the material has greatly improved.