两种纤维加筋模拟月壤地聚合物动态劈裂试验研究

Dynamic splitting tests of simulated lunar soil geopolymer reinforced with two types of fibers

为了解纤维加筋模拟月壤的动态劈裂力学特性,选用聚丙烯纤维和玄武岩纤维制备了纤维加筋模拟月壤地聚合物圆盘试件,利用分离式霍普金森压杆(split Hopkinson pressure bar,SHPB)装置开展了冲击劈裂试验,并使用扫描电子显微镜观察地聚合物断裂面处纤维的分布排列情况。试验结果表明:当聚丙烯纤维掺量为0.4%时试件的劈裂拉伸强度达到最大,较未掺时提高22.9%~27.3%;相同纤维掺量下,聚丙烯纤维对试件劈裂拉伸强度的增益效果要优于玄武岩纤维;纤维掺量一定时,试件动态劈裂拉伸强度与冲击气压呈正相关,纤维对劈裂拉伸强度的增益效果与冲击气压呈负相关;试件在冲击荷载作用下沿轴向劈裂为相对完整的两半,纤维的掺入减小了试件的破坏程度,改善了脆性破坏;试件的劈裂破碎块度平均粒径随纤维掺量的增加而增大。研究结果为未来月球基地建造材料的选择提供参考。

Here,to understand dynamic splitting mechanical properties of fiber-reinforced simulated lunar soil,polypropylene fibers and basalt fibers were used to prepare geopolymer disc specimens of fiber-reinforced simulated lunar soil.Impact splitting tests were conducted using a split Hopkinson pressure bar(SHPB)device,and distribution and arrangement of fibers at fracture surface of geopolymer were observed using a scanning electron microscope.Test results showed that when content of polypropylene fiber is 0.4%,splitting tensile strength of specimen reaches the maximum,it is 22.9%-27.3%higher than that without polypropylene fiber adding;under the condition of the same fiber content,the increase effect of polypropylene fiber on splitting tensile strength of specimen is better than that of basalt fiber;when fiber content is constant,dynamic splitting tensile strength of specimen is positively correlated with impact pressure,while the increase effect of fibers on splitting tensile strength is negatively correlated with impact pressure;specimen splits into relatively intact halves along axial direction under impact load,and adding fibers reduces failure degree of specimen and improves brittle failure;average particle size of splitting fragmentation of specimen increases with increase in fiber content;the study results can provide a reference for selecting construction materials of future lunar bases.